biology of the rattlesnakes symposium - Dr. William Hayes

BIOLOGY OF THE RATTLESNAKES SYMPOSIUMOrganizersA symposium of this nature would not be possible without the thoughtful planning anddecision-making by a number of individuals. Fortunately, we are blessed with a cadre of researchers havinginterest and enthusiasm for organizing a successful symposium. They include the following:Co-organizers of the symposium (from left to right):Michael CardwellSean BushKent BeamanWilliam HayesLocal Members of Organizing Committee:William Hayes, chairSean BushMichael CardwellRonald CarterEric DuganAlex FigueroaScott HerbertConsulting Members of Organizing Committee:Gordon SchuettKelley Kissner3

BIOLOGY OF THE RATTLESNAKES SYMPOSIUMSponsorsWe are grateful to the following organizations who have generously sponsored the symposium. Theircontributions have made possible many of the special events and meals that participants will enjoy.FougeraMarketer and distributor of CroFab antivenomRed Rock BiologicsMarketer and distributor of rattlesnake venom vaccine for dogsAnimal Capture Equipment, Inc.Provider of handling and capture equipmentVendors and ExhibitorsBe sure to visit these companies and individuals to expand your horizons...Avid Microchip I.D. SystemsImplantable microchip identification systemsAVM Instrument Company Ltd.Radiotracking equipment and servicesDonald E. Hahn / Natural History BooksHerpetological and other natural history booksEagle Mountain PublishingPublisher of specialty herpetology booksHolohil Systems Ltd.Radiotracking equipment and servicesMidwest tongs.comSnake and reptile handling equipmentWilliam MontgomeryOriginal herpetology artZoo Book SalesNatural history books from around the worldECO Herpetological Publishing &DistributionHerpetological clothing, books, and arts4

BIOLOGY OF THE RATTLESNAKES SYMPOSIUMSpecial EventsSaturday Evening: Registration and Authors' EveningYou won’t want to miss this event. After receiving your registration materials, you can enjoy a socialmixer with several unique highlights. A number of book authors will be present and willing to autograph yourbooks (that you can purchase on-site from vendors). We will also feature a slide presentation by MannyRubio, a well-known rattlesnake photographer and author.Below is a list of book authors expected to be present and willing to autograph books:Daniel BeckRonald Carter& William HayesHarold De LisleCarl ErnstHenry FitchJoseph GennaroLee GrismerJeffrey LovichManny RubioFindlay RussellRobert StebbinsAnthony TuBiology of the Gila Monsters and Beaded LizardsIguanas: Biology and ConservationThe Natural History of Monitor LizardsVenomous Reptiles of North America, Snakes of the United States and Canada,Snakes of Eastern North America, Turtles of the World, Turtles of the UnitedStates and Canada (Dr. Ernst expects to arrive on Sunday)Autecology of the Copperhead, Sexual Size Differences in Reptiles, ReproductiveCycles in Tropical Reptiles, A Kansas Snake CommunitySmall Worlds Close UpAmphibians and Reptiles of Baja CaliforniaTurtles of the United States and CanadaRattlesnakes, Portrait of a Predator; ScorpionsSnake Venom PoisoningA Field Guide to Western Reptiles and AmphibiansRattlesnake Venoms; Reptile Venoms and Toxins; Chemical Terrorism; andothersSunday Morning: Keynote Speaker, David Chiszar (University of Colorado)Cruising for herps. David Chiszar and Hobart Smith setout on a collecting trip. Photograph: Joan Chiszar.Dr. Chiszar, the much-beloved authority on rattlesnake feeding behavior, willdazzle the audience with anecdotes of remarkable discoveries and amusingexperiences accumulated during a career devoted to the study of thingscold-blooded.Born in Iowa to a military pilot and raised in New Jersey, Dr. Chiszar earnedall of his advanced degrees from Rutgers University (B.A. 1966, M.S. 1969,Ph.D. 1970). Ever since, he has been a faculty member in the Department ofPsychology at Colorado University.His specialties include animal behavior and statistics, but in his own words,"Rattlesnakes were my first love and they remain my greatest love." Hisstudies have focused largely on the unique feeding specializations ofrattlesnakes. Of more than 800 publications to his credit (including papers,chapters, and abstracts), more than 240 have dealt in whole or in part with5

attlesnakes. He continues to work very closely with his dear friend, Hobart Smith, with whom he hascollaborated on many publications. Among his favorite pastimes, he recalls with fondness the manycollecting expeditions they enjoyed together--sometimes by motorcycle--traveling as far as Texas andMexico.Sunday Night: Banquet with Janet Klauber and Emeritus PanelThis extraordinary event will never be forgotten!The program will open with Janet Klauber giving a 30-minutepresentation on her late grandfather, Laurence Klauber, whosetwo-volume masterpiece, Rattlesnakes: Their Habits, Life Histories, andInfluence on Mankind, continues to inform and inspire researchers today.The presentation, entitled “Laurence M. Klauber 1883-1968: RenaissanceMan in San Diego,” will include a recording of him speaking.The remainder of the program will feature a panel of retiredresearchers who will be honored for their significant contributions to ourunderstanding of rattlesnake biology. David Chiszar, the keynote speaker,will host a stimulating question-and-answer session with the panelmembers. Questions can be submitted by symposium participants duringthe morning and afternoon sessions preceding the banquet. A slide showfeaturing images of panel members during their illustrious careers willaccompany the event.Laurence M. Klauber.Courtesy of Janet Klauber.The panel will tentatively include the following individuals:William S. Brown (Professor Emeritus, Skidmore College) - Since 1978, Dr. Brown has collected26 years of data on the natural history and ecology of Timber Rattlesnakes, earning The NatureConservancy's (Eastern New York Chapter) annual Oak Leaf Award in 2003. He currently leads agroup of research biologists preparing the Conservation Action Plan for the Timber Rattlesnake.Henry S. Fitch (Professor Emeritus, University of Kansas) - In the 1940's, Dr. Fitch conducted thefirst major field studies of rattlesnakes in the foothills of California's Sierra Mountains. Hesubsequently studied a wide range of organisms, including Timber Rattlesnakes, at the Universityof Kansas ecological reserve which now bears his name.Peter H. Hartline (Retired Professor, Massachusetts) - As members of the pitviper subfamilyCrotalinae, rattlesnakes possess heat-sensitive infrared pits that function much as eyes do, allowingsnakes to "see" endothermic (warm-blooded) targets in complete darkness. Dr. Hartline publisheda remarkable series of articles exploring the neuroanatomy and physiology of these unique organs.Findlay E. Russell (Professor Emeritus, University of Arizona) - During decades committed topatient treatment and research on rattlesnake bites and venom biochemistry, Dr. Russell authoredhundreds of publications, including the widely-acclaimed book, Snake Venom Poisoning. Dr. Russellactually earned his M.D. from Loma Linda University, and thus returns as an alumnus.Robert C. Stebbins (Professor Emeritus, University of California, Berkeley) - Dr. Stebbins hasauthored more than a dozen books, including the highly influential A Field Guide to Western Reptilesand Amphibians. As a gifted artist, his numerous paintings and prints of reptiles and amphibians areprized by collectors.6

11:45 am Miklós Sahin-Tóth and Zoltan TakacsSurviving between infrequent meals: Enhanced stabilization of rattlesnake (Crotalus)trypsinogens12:00 pm LUNCH – Provided to registered participants; sponsored by Fougera1:00 pm SPECIAL LECTUREAnthony T. TuForty years of venom research1:15 pm SESSION 3: BEHAVIOR & ECOLOGY OF CALIFORNIA RATTLESNAKESChairpersons: Donald H. Owings and Richard G. Coss1:15 pm Harold F. De LisleSharing the resource: Six species of rattlesnake in Joshua Tree National Park1:30 pm Eric A. Dugan and William K. HayesComparative ecology of Red Diamond (Crotalus ruber) and Southern Pacific (Crotalushelleri) Rattlesnakes in southern California1:45 pm Tracey K. Brown, Jeff Lemm, J. P. Montagne, and Allison AlbertsMovement, denning, and relocations of Red Diamond Rattlesnakes (Crotalus ruberruber) at the San Diego Wild Animal Park2:00 pm Michael D. CardwellHabitat utilization and behavior of the Mohave Rattlesnake (Crotalus scutulatusscutulatus) in the Western Mohave Desert2:15 pm David B. GreenbergThe effects of surface insolation on shelter site selection by Crotalus mitchelli and C.ruber2:30 pm Kenneth J. Halama, Adam J. Malisch, Tracy Tennant, Michael Aspell, and John T.RotenberryModeling the landscape niche characteristics of the Red Diamond Rattlesnake (Crotalusruber) utilizing a partitioned Mahalanobis D 2 statistic: Implications for biology andconservation2:45 pm Ali M. RabatskyRattle loss in insular rattlesnake species3:00 pm BREAK – Sponsored by LLU Department of Earth & Biological Sciences3:15 pm Donald H. Owings and Richard G. CossHunting ground squirrels: Constraints and opportunities for rattlesnakes3:30 pm Barbara Clucas, Matthew P. Rowe, and Donald H. OwingsSheep in wolves’ clothing?: Snake scent application in ground squirrels3:45 pm Aaron R. Rundus and Donald H. OwingsInfrared communication: The use of a snake-directed infrared signal by CaliforniaGround Squirrels (Spermophilus beecheyi) during predatory encounters with NorthernPacific Rattlesnakes (Crotalus viridis oreganus)4:00 pm RECESSWe have to clear the facility to allow banquet set-up7:00 pm BANQUET – Sponsored by Fougera and Red Rock BiologicsJanet Klauber – Granddaughter of the late Laurence M. KlauberLaurence M. Klauber 1883-1968: Renaissance man in San DiegoEmeritus Panel – Lively discussion with the retired experts!William S. Brown, Henry S. Fitch, Peter H. Hartline, Findlay E. Russell, Robert C.Stebbins, Anthony T. Tu10

1:00 pm POSTER SESSION – Sponsored by FougeraJoseph Agugliaro and Howard K. ReinertA comparison of skin permeability within and between two populations of the TimberRattlesnake (Crotalus horridus)Craig S. Berg and Armund BartzWinter biology of Timber Rattlesnakes, Crotalus horridus, in WisconsinCraig S. Berg, Richard A. Sajdak, and Armund BartzReproductive cycles of female Timber Rattlesnakes, Crotalus horridus, in the upperMississippi River ValleyRobert W. Bryson, Jr. and David LazcanoObservations on the thermal ecology of montane Mexican RattlesnakesSean P. Bush, Steven M. Green, Torrey A. Laack, William K. Hayes, Michael D.Cardwell, and David A. TanenPressure-immobilization delays mortality and increases intra-compartmental pressureafter artificial intramuscular rattlesnake envenomation in a porcine modelMichael D. Cardwell, Sean P. Bush, and Robin T. ClarkMales biting males: Does testosterone shape both sides of the snakebite equation?Tim ColeColor/pattern morphs in rattlesnakes with emphasis on central Texas Crotalus atroxMichael J. Dreslik, Thomas G. Anton, Michael J. Dreslik, Christopher A. Phillips,David Mauger, Thomas P. Wilson, Donald B. Shepard, Alan Resetar, and Benjamin C.JellenMonitoring the continuing decline of the Eastern Massasauga (Sistrurus catenatus) inIllinoisDaniel D. FogellStatus of the Prairie Rattlesnake (Crotalus viridis) in the Loess Hills of northwest IowaWilliam K. HayesThe snake venom-metering controversy: Levels of analysis, assumptions, and evidenceCraig S. Ivanyi and Hugh K. McCrystal.Translocation of venomous reptiles in Pima County, Arizona: Advice and consent ordissent?Kate Jackson and Bruce YoungFunctional specialization of the extrinsic venom gland musculature in crotaline snakes:What is the role of the M. Pterygoideus Glandulae?John P. LaBonteInnate prey preference in neonatal Southern Pacific Rattlesnakes (Crotalus viridis helleri)and changes with ontogenyKim Lovich, Kent R. Beaman, and Clark R. MahrdtA curator and his rattlesnakes: The history of Laurence Monroe Klauber at the San DiegoZooMichael A. MalawyThermal biology of Crotalus atroxMatthew McMillan and Carl S. LiebMorphological variation in Crotalus basiliscus and Crotalus molossus (Serpentes:Viperidae) with an evaluation of hybridizationEstrella Mociño Deloya, Kirk Setser, and David Lazcano VillarrealCannibalism of non-viable offspring by post parturient female Crotalus polystictusZia Nisani, William K. Hayes, Joseph Banishek, and Joseph Banishek, Jr.Factors associated with nocturnal activity in the western Mojave Desert: Rattlesnakesversus nonvenomous snakesTommy OwensFire ecology of a southern California rattlesnake: A case of survivalTracy J. Patten, Daniel D. Fogell, and James D. FawcettConservation of the Massasauga (Sistrurus catenatus) in southeast Nebraska12

Michael S. PriceGeographic variation in Crotalus lepidus lepidus from Texas.Ali M. RabatskyCaudal luring as a precursor in rattle evolution: A test using an ancestral rattlesnake,Sistrurus miliarius barbouriRichard A. Sajdak, Craig S. Berg, and Robert W. HayTimber Rattlesnake (Crotalus horridus) dens in WisconsinJustin SchoferPopulation modeling of Arizona Black Rattlesnakes (Crotalus oreganus cerberus) at aden site near Flagstaff, ArizonaRonald M. Smith, Walter F. Bien, and James R. SpotilaSpatial ecology of the Timber Rattlesnake in the pinelands of southern New JerseyTamara L. Smith and Kenneth V. KardongBinary cues in rattlesnake poststrike trailingRobert E. Weaver and M. E. LahtiDiet of the Northern Pacific Rattlesnake (Crotalus viridis oreganus) in the Yakima RiverCanyon of central Washington stateSteven D. WermanA phylogenetic perspective on the evolution of the biological properties of rattlesnakevenom1:55 pm SESSION 6: SNAKEBITE & TREATMENTChairperson: Sean P. BushWELCOMERoger Hadley - Dean, School of Medicine, Loma Linda University2:00 pm FEATURED SPEAKERRichard C. DartResearch needs in snake envenomationSponsored by Fougera2:45 pm Sean P. BushPre-hospital, first aid, and field considerations in rattlesnake bite3:00 pm Jude McNallySnake bite: Not just a young man’s disease, part I3:15 pm Leslie BoyerSnake bite: Not just a young man’s disease, part II3:30 pm Steven A. SeifertRecurrence phenomena in antivenom-treated crotaline bites3:45 pm Daniel E. KeylerTimber Rattlesnake (Crotalus horridus) envenomations in the Upper Mississippi RiverValley4:00 pm William K. Hayes, Sean P. Bush, Shelton S. Herbert, G. Curtis Rehling, Michael D.Cardwell, and Eric A. DuganDefensive bites by rattlesnakes (genus Crotalus): Venom expenditure, envenomationseverity, and the importance of snake size4:15 pm Donald N. Janes, Jr., Sean P. Bush, Thomas Schilling, and Gita R. KolluruLarge snake size suggests increased snakebite severity in patients bitten by rattlesnakes insouthern California4:30 pm BREAK – Sponsored by LLUMC Department of Emergency Medicine4:45 pm SESSION 7: RATTLESNAKE BEHAVIORChairpersons: Kenneth V. Kardong and Tamara L. Smith13

A telemetric study of the survivorship, behavior, and spatial ecology of neonatal TimberRattlesnakes, Crotalus horridus11:00 am Daniel D. Fogell and James D. FawcettEcology and conservation of the Timber Rattlesnake (Crotalus horridus) in Nebraska11:15 am Robert T. Zappalorti and Howard K. ReinertHabitat use, foraging behavior, and overwintering sites of Timber Rattlesnakes(Crotalus horridus) in the New Jersey Pine Barrens11:30 am Earl E. Possardt, William H. Martin, William S. Brown, and John SealyA range wide action plan for the Timber Rattlesnake (Crotalus horridus): Hope for actualconservation progress or more paper?11:45 am SESSION 10: RATTLESNAKE BEHAVIORChairperson: Matthew P. Rowe11:45 am Shelton S. Herbert and William K. HayesVenom expenditure by rattlesnakes: Optimality, risk assessment, and protection affordedby blue jeans12:00 pm LUNCH – Provided to registered participants; sponsored by Fougera1:00 pm SESSION 10: RATTLESNAKE BEHAVIOR (continued)Chairperson: Matthew P. Rowe1:00 pm Charles I. Abramson and Aaron J. PlaceLearning in snakes I: A program of research on learning in rattlesnakes1:15 pm Aaron J. Place and Charles I. AbramsonLearning in snakes II: Empirical studies of learning in rattlesnakes1:30 pm Edwin M. McGowanA composite record of mating behavior in free-ranging Timber Rattlesnakes, Crotalushorridus1:45 pm Melissa Amarello, Kevin Bonine, and David LazcanoDefensive behavior of Crotalus polystictus (Mexican Lance-headed Rattlesnake) towardshumans2:00 pm Alex Figueroa, Eric A. Dugan, and William K. HayesBehavioral ecology of neonate Southern Pacific Rattlesnakes (Crotalus helleri) insouthern California2:15 pm Matthew P. Rowe and John B. SealyHibernaculum or bust: Species preferences in the scent-trailing behavior of neonataltimber rattlesnakes (Crotalus horridus)2:30 pm SESSION 11: ECOLOGY OF NORTHWESTERN RATTLESNAKESChairperson: Charles R. Peterson2:30 pm Christopher L. Jenkins and Charles R. PetersonLinking landscape disturbance to population level variation in western rattlesnake lifehistories2:45 pm Dennis Jorgensen and C. Cormack GatesDifferential movement patterns among non-gravid female Prairie Rattlesnakes (Crotalusv. viridis) at the northern extent of their range3:00 pm Harry Parsons and Mike SarellManaging a landscape with rattlesnakes3:15 pm Jeffery R. Brown (University of Guelph), Christine A. Bishop, Brenda Baptiste, andRonald J. BrooksThe effects of short-distance translocation on the Northern Pacific Rattlesnake (Crotalusoreganus) in southern British Columbia, Canada: Preliminary results and observations15

3:30 pm BREAK – Sponsored by Animal Capture Equipment, Inc.3:45 pm Vincent A. Cobb and Charles R. PetersonThermal ecology of hibernation in the Great Basin Rattlesnake (Crotalus oreganuslutosus)4:00 pm Bryan HamiltonUse of solar models and GIS to evaluate potential hibernacula in the Great BasinRattlesnake (Crotalus lutosus)4:15 pm SESSION 12: ECOLOGY & CONSERVATION OF SISTRURUSChairperson: Terence M. Farrell4:15 pm Terence M. Farrell, Peter G. May, and Melissa A. PilgrimAnnual variation in yearling recruitment to a population of Sistrurus miliarius4:30 pm Bruce A. Kingsbury (Indiana-Purdue University), Joseph R. Sage, Jennifer V. Manning,and John MarshallSpatial ecology and conservation of the Eastern Massasauga4:45 pm Yu Man Lee, Lori G. Sargent, and Bruce A. KingsburyDeveloping a conservation strategy for the Eastern Massasauga in Michigan5:00 pm Andrew T. Snider, Yu Man Lee, Daria Hyde, and Rebecca ChristoffeThe Eastern Massasauga, Sistrurus c. catenatus, in Michigan: Conservation througheducation5:15 pm Robert L. CarmichaelThe grass is rattling: A grass roots conservation education program to bring publicawareness about rattlesnakes and their importance to the environment5:30 pm AFTERWORDSymposium OrganizersConcluding remarks and comments for contributors to the volume (we’ll be very brief)16

Snake defensive behavior can vary with sex,reproductive condition, size, and temperature. Wecharacterized defensive behavior of Crotalus polystictus(Mexican Lance-headed rattlesnake) during laboratorybehavioral trials to investigate the influence ofreproductive condition and temperature. C. polystictusis a little studied pit viper endemic to the MexicanPlateau. Much of their habitat has been converted foragricultural use, and dense populations live in closeproximity to humans. Frequent encounters betweenhumans and snakes often lead to bites and death of thesnake. Male C. polystictus were more defensive thangravid females, while temperature had little effect ontheir behavior. We discuss the ecological causes andconsequences of the observed differences.Beaupre, Steven J. Department of Biological Sciences,601 Science-Engineering Building, University ofArkansas, Fayetteville, AR, 72701.Rattlesnakes as model systems for understandingenvironmental change: Responses of TimberRattlesnakes to variation in food availability.Observations of complex behavioral and physiologicalresponses of individuals and populations to naturalenvironmental variation can yield valuable insight forunderstanding potential responses to directionalenvironmental change. Rattlesnakes are excellent modelsystems for such observations because the use ofradiotelemetry facilitates behavioral and physiologicalsampling over extended periods. I measured behavioraland physiological responses of radio-tagged TimberRattlesnakes (Crotalus horridus) in Northwest Arkansasduring periods of high and low food availability. Underconditions of low food availability, snakes exhibitedmore time foraging, fewer ingested meals, reducedgrowth, lower field metabolic rates (FMR), poorer bodycondition, and no evidence of reproductive activity(mate search, courtship, or follicular development).Conversely, under conditions of high food availability,snakes foraged less, consumed more food, grew faster,had increased FMR, improved body condition, andexhibited extensive mate search, courtship, and folliculardevelopment. Analysis of environmental and bodytemperatures suggests that thermal effects contributedlittle (if any) to the causal basis of observed differences.I conclude that there is strong but circumstantialevidence that food availability is a fundamental factordriving individual and population responses of lowenergyadapted Timber Rattlesnakes. These data matchwell with predictions from simulation modeling, and arelikely to be typical of low-energy crotaline snakes.Beck, Daniel D. Department of Biological Sciences,Central Washington University, Ellensburg, WA 98926,USA.Ambush-site selection by Sonoran desertrattlesnakes: a field experimentNocturnal desert rodents are important prey forrattlesnakes. During the summer rainy season in theSonoran desert Crotalus spp. often move from coverunder shrubs and rocks during the day to lie coiled andalert in the open at night. I addressed whetherrattlesnakes selected these "ambush postures" at randomby testing their ability to respond to experimenterinducedrodent trails. I used radiotelemetry to monitormovements of six rattlesnakes (C. atrox and C. tigris) onan Arizona Upland site near Tucson, AZ. I filled seedtrays with millet dusted with florescent powder, thenarranged the trays on a grid within areas occupied byradio-equipped snakes. Pocket mice (Perognathus spp.)and kangaroo rats (Dipodomys spp.) removed seeds fromthese trays, leaving conspicuous trails detectable at nightwith an ultraviolet lantern. I measured the distance fromsnake "ambush sites" to the nearest rodent trail andcompared them with sites potentially chosen if snakeshad moved in random directions on the grid. Snakes thatremained on the seed-tray grids chose ambush locationsthat were significantly closer to the induced rodent trailsthan were randomly-selected ambush sites. Directobservations of foraging movements suggest thatrattlesnakes actively search for appropriate foraginglocations before settling on an ambush site. My resultsindicate that in nature rattlesnakes show the same preyodor discrimination when choosing ambush sites as theydo when following chemical trails after striking andenvenomating their prey. Other researchers mightbenefit from using this field technique to investigateforaging behavior of rattlesnakes and the potentialresponses shown by their prey.Berg 1 , Craig S. and Armund Bartz 2 .1 Department ofBiological Sciences, University of Wisconsin-Milwaukee, 3209 N. Maryland Ave, Milwaukee, WI53211, Milwaukee County Zoological Gardens, 10001W. Blue Mound Rd., Milwaukee WI 53226, 2 WisconsinDepartment of Natural Resources Endangered ResourcesProgram, 3550 Mormon Coulee Road, La Crosse, WI54601.Winter biology of Timber Rattlesnakes, Crotalushorridus, in Wisconsin.Between 1999 and 2004, the body temperature (T B s) of15 timber rattlesnakes were recorded at 6 hibernacula(N=518 records) using temperature sensitive transmittersimplanted into the coelomic cavity. Entrances to thehibernacula were located adjacent to bluff prairies onwest facing slopes. Most individuals enter dens duringlate September and early October and exit during May.The earliest recorded ingress occurred on September 10.The latest ingress occurred on October 19. The earliestrecord of emergence was April 04 and the latestemergence occurred after June 1. The average T B for all18

ecords was 10.3ºC (range 5.0ºC - 18.9ºC). The averageT B at all 6 dens (October 2003 to May 2004) was 10.7ºC.The average T B at the main study site, recorded betweenOctober and May (3 years, N= 175 records) was 11.1ºC.At this site, the approximate location of each snake inthe den was recorded by localizing the source of thestrongest radio signal. The yearly minimum T B wasreached during March in all six years of this study.Movements toward the den entrance begin in late March.Weight loss during brumation for 11 snakes averaged10.2% (range 3.7 - 19.4%, N= 24 records). Females(N=5, 11 records) lost an average of 9.9% while males(N=6, 13 records) lost an average of 10.5% of their fallbody weight. Percent weight loss was not correlatedwith differences in size class (by weight). Temperatureprofiles will be displayed.Berg, Craig S. 1,2 , Richard A. Sajdak 3 and ArmundBartz 4,2 1 Department of Biological Sciences, Universityof Wisconsin-Milwaukee, 3209 N. Maryland Ave,Milwaukee, WI 53211, 2 Milwaukee County ZoologicalGardens, 10001 W. Blue Mound Rd., Milw. WI 53226,34 Callingham Road, Pittsford, NY 14534, 4 WisconsinDepartment of Natural Resources, EndangeredResources Program, 3550 Mormon Coulee Road, LaCrosse, WI 54601.Reproductive cycles of female Timber Rattlesnakes,Crotalus horridus, in the upper Mississippi RiverValley.Between 1999 and 2004, 7 radio-equipped female timberrattlesnakes (35 snake/years) at several sites in westernWisconsin produced 15 clutches. Mean inter-clutchinterval was 3.14 years (range 2-5 years). Thiscontradicts the findings of a previous study of Wisconsintimber rattlesnakes (Keenlyne, K.D. 1978), who reporteda biennial reproductive cycle. Keenlyne’s results wereskewed by an overestimation of shedding frequency,resulting in over estimates of growth rates and frequencyof reproductive episodes. He estimated snakes with asmany as 8 rattle segments to be in their third summer ofgrowth, 6 or more sheds in 2+ years. Our results, based16 rattlesnakes (12 %%, 4 &&) recaptured after at least 1year, demonstrate a much lower rate, mean sheds/year =1.74 (range 1-2.7). Juvenile snakes (> 65cm SVL at firstcapture) shed most frequently (1.85 sheds/yr). Malesshed more frequently than females (1.80 vs. 1.54sheds/yr). Reanalyzing Keenlyne’s published data usingan annual shedding frequency of two or less, shifts ageat first reproduction to 7-9 years (vs. his estimate of 4years) and a triennial or greater reproductive cyclewhich better fits both his data set and our findings.Biardi, James E. PROF Postdoctoral Program,University of California Davis, 1 Shields Ave., Davis,CA 95616The ecological and evolutionary context ofmammalian resistance to snake venomsSnake venoms are a complex mixture of proteins,polypeptides, biogenic amines, and other componentsthat may have neurotoxic, hemostatic, and/orhemorrhagic effects on prey. Their primary functions areto immobilize prey and initiate the process of digestion.However, some mammals are able to neutralize at leastsome of the toxins in snake venoms through an innate,not an induced, response to predation. For prey, thehemostatic and hemorrhagic effects of snake venommetalloproteases pose a significant threat apart fromdeath, since they can reduce fitness due to tissuedestruction and necrosis. In some mammals (includingfive marsupials, two hedgehogs, a shrew, a mole, fourmongoose, a raccoon, two mustelids, and 15 rodents[three sciurid and eight murid rodents]) this threat hasbeen met by endogenous serum proteins that areeffective snake venom metalloprotease inhibitors.However, there are significant gaps in our knowledge ofinnate defenses against venomous snakes, and acomparative approach will lead to new insights abouttoxicity and resistance that results from the arms racebetween these predators and their prey. An examinationof the literature from an evolutionary and ecologicalperspective reveals previously unexplored patterns invenom resistance. Current research on California groundsquirrel (Spermophilus beecheyi) and rock squirrel(Spermophilus variegatus) resistance to rattlesnakevenom is presented as an example of how a comparativeapproach can lead to new insight into the coevolution ofvenomous snakes and their prey.Boyer, Leslie V. 1 and Jude T. McNally 2 . 1 Departmentof Pediatrics1 and Arizona Poison and Drug InformationCenter, 1,2 University of Arizona Health Sciences Center,1501 N. Campbell Ave., Tucson AZ 85724.Snakebite: Not just a young man’s diseaseIn the United States, traditional medical teaching holdsthat snakebite is a disease primarily of risk-taking youngmen. As a result, many analyses of first aid measures,disease course, treatment and outcome presuppose thatthe great majority of victims are young, strong, andbitten on the finger. Anecdotal reports of snakebitesinvolving girls or 80-year-olds are commonly lumpedtogether as “legitimate,” or accidental, bites, from whichno pattern is presumed to emerge. But what do the actualdata show? In this presentation we will review findingsfrom 450 snakebite reports, over a 3-year-period, to theArizona Poison and Drug Information Center. Analysisof case reports demonstrates remarkable concordancebetween women and men in the occurrence of lowerextremity bites, but dramatic differences in upperextremity injuries. Trends with age show a peak in bitesfor men in early middle age, with the peak incidence forwomen occurring later. Specific attention to 50 cases19

involving victims over age 60 reveals that physicalimpairment and gardening activities appear to influencethe likelihood of envenomation among the elderly, butthat male-female differences in snake interactions persistthrough the 80’s. We conclude that accidentalsnake-stomping is independent of victim age and sex,that hand bites are primarily a male-victim phenomenon,that older gardeners should wear reading glasses, andthat maleness becomes, if anything, more severe withage.Brown 1 , Jeffrey R., Christine A. Bishop 2 , BrendaBaptiste 3 , Ronald J. Brooks 11Department of Zoology, University of Guelph, Guelph,ON, N1G 2W1, 2 Canadian Wildlife Service, 5421Robertson Rd., Delta, BC, V4K 3N2, 3 Nk’Mip Desertand Heritage Centre, 1000 Rancher Creek Rd., Osoyoos,BC, V0H 1V6.The Effects of Short-Distance Translocation on theNorthern Pacific Rattlesnake (Crotalus oreganus) inSouthern British Columbia, Canada: PreliminaryResults and ObservationsSeveral wildlife agencies in British Columbia currentlyrecommend short-distance translocation (SDT) as amanagement strategy in areas of human activity in anattempt to keep both rattlesnakes and humans safe.However, due to a lack of information, the effects ofSDT on rattlesnakes remain largely unknown. In 2004,we implanted 20 rattlesnakes with radio-transmitters andcontinued a mark-recapture program at the Nk’MipDesert and Heritage Centre in Osoyoos, BC, todetermine the effects of STD on rattlesnake movementpatterns and survival and to evaluate the effectiveness ofSDT as a management/conservation strategy.Rattlesnakes captured in areas of human activity wereprocessed and released in natural habitat at distancesbetween 200m and 1000m from initial capture locations.Preliminary results suggest SDT causes an increase inrattlesnake movements over the summer activity period,with movement distance increasing with translocationdistance. Observed mortality was significantly lower innatural habitat (n=0) compared to areas of humanactivity (n=8). All observed mortality was associatedwith human interaction. To date, no mortality has beenobserved in snakes implanted with radio-transmitters,which appears to be due to prompt removal from areasof human activity. A significant number of rattlesnakessubjected to SDT (71%) returned to the area of theirinitial capture. The mean time to return to areas ofhuman activity decreased with increasing translocationdistance (n=19 days at 500m and n=16 days at 1000m).Preliminary results suggest SDT does negativelyinfluence rattlesnakes through increased movementdistances but benefits rattlesnakes through decreasedmortality rates. SDT appears to be an effective strategyto gain “snake free” time in areas of human interactionbut does not entirely solve the problem of “nuisance”rattlesnakes in areas of human activity.Brown 1 , Tracey K., Lemm, Jeff 2 , Montagne, J.P. andAllison Alberts 2 . 1 Department of Biological Sciences,CSU San Marcos, San Marcos, CA 92096. 2 AppliedConservation Division, Conservation and Research forEndangered Species, 15600 San Pasqual Valley Road,Escondido, CA 92027.Movement, denning and relocations of Red DiamondRattlesnakes (Crotalus ruber ruber) at the WildAnimal Park.Approximately half of the Zoological Society of SanDiego’s Wild Animal Park (WAP) 1800 acre facility ismanaged as an ecological preserve. This land, which isalso part of San Diego’s Multiple Species ConservationProgram, supports an extremely rich biota and 16species of snake have been found at the site includingCrotalus ruber ruber, C. viridis helleri and C. mitchelliipyrrhus. We used radio-telemetry to follow severaladult C. r. ruber (“residents”; N=12) over a four yearperiod (2000 through 2003) to learn more about thisspecies’ movement ecology (especially with respect toroads) and overwintering habits. Furthermore, for safetypurposes these snakes are occasionally relocated awayfrom animal enclosures and pedestrian paths by WAPstaff. We used these opportunities to study the effects ofrelocation (both short and long-distance) on themovement ecology and survivorship of C. r. ruber(“relocates”; N=5). Home range sizes varied greatlybetween years, sexes and initially between relocated andresident snakes. Male resident snake home ranges werenearly triple that of females, and the males typicallymoved twice as far as females during an activity season.Resident MCP home ranges varied between 0.3 to 6.2 hawhile relocates used from 1.6 to 18 ha. The home rangeareas and distances moved by the relocated snakesdecreased with time. Most snakes at the WAP usedlarge rock outcrops as dens, with up to seven snakes ina den, for overwintering. Two of the snakes relocatedlong-distances (>1000 m) were able to locate dens usedby other snakes in their new areas. These and otherresults will be discussed in detail.Brown 1 , William S., Marc Kery 2 , and James E. Hines. 31Department of Biology, Skidmore College, SaratogaSprings, NY 12866, 2 Swiss Ornithological Institute,36204 Sempach, Switzerland, Patuxent WildlifeResearch Center, U.S. Geological Survey, Laurel, MD20708Long-term ecology of Crotalus horridus: dens,survival, and longevityIn the southeastern Adirondack Mountains of New Yorknear the northern limits of its range, timber rattlesnakedens occur in Appalachian oak-hickory forest within thenorthern hardwoods-boreal transition zone. A linear20

series of dens in steep rockslides under prominent SEfacingcliffs spanning 12 km has been under continuousstudy by the senior author since 1978. Here we discussthe timber rattlesnake's local population structure,survival estimates by capture-recapture modeling, andbody size and longevity. Through 2002, samplingtotaled 1466 field days over 25 years (mean 58 d/yr) andyielded 4025 captures of all ages and sizes. Denpopulations suggested by total captures vary widely,from 42 to 558 new individuals captured in adjacentdens; den population size is not clearly correlated withphysical size of the rockslide. Shifts (den interchanges)from one den to another totalled only about 1% of totalrecaptures. A microgeographic cline in color morphratios (57% black-morph in a northern den to 20% in asouthern den) suggests that reduced gene flow and/ordifferential human predation have occurred within thiscomplex of dens. We used capture histories of 588marked neonates, including lab-born (LAB, n=181) andfield-born (FLD, n=407) snakes, to estimate annualsurvival. The data satisfied goodness-of-fit tests andsupported assumptions of the general Cormack-Jolly-Seber (CJS) model, allowing use of AIC-ranked models.Recapture rates declined from about 20% over timewhile increasing among older age-classes. Estimatedfirst-year survival rates were 0.30 to 0.41 (LAB) and0.53 to 0.77 (FLD). Lower LAB birth weightscombined with a lack of field exposure until releaseapparently contributed to their lower survival rate. InFLD snakes, subsequent survival estimates were 0.83 to0.98 (years 2-4) and 0.80 to 0.93 (years 5+). Over this27-year study, recapture intervals of 22 and 23 years forsnakes initially marked as adults indicate the naturallifespan approaches 35 years. Over the years, theaverage body mass has increased by about 11% in gravidfemales and 12% in large (>1000 g) males.Bryan, Danny L., School of Arts and Sciences,Cumberland University, One Cumberland Square,Lebanon, TN 37087Foraging behavior by young of year timberrattlesnakes (Crotalus horridus).Timber rattlesnakes, Crotalus horridus, have beenfrequently described as ambush predators. Since there isnot any nurturing during the development of these youngrattlesnakes, the question arises as to how prey is locatedand captured. The foraging habits performed by youngof year timber rattlesnakes were observed and recordedfrom two feeding sessions in a laboratory setting. Twoseparate litters were utilized during the observations anddifferences were noted and analyzed. A simple T mazewas constructed and lab mice were allowed to leave atrail within the maze. Individual snakes were thenallowed to trail the scent and forage. A total of 18 snakeswere utilized in the trial from two litters, n =12 and n =8. Differences between the two litters were noted andwill be presented.Bryson 1 , Jr., Robert W. and David Lazcano 2 . 1 113Walnut St. #97, Neptune, New Jersey 07753,2 Laboratorio de Herpetología, Universidad Autónoma deNuevo León, Apdo. Post. 513, C.P. 66450, San Nicolasde los Garza, Nuevo León, México.Observations on the Thermal Ecology of MontaneMexican RattlesnakesThe thermal ecology of rattlesnakes inhabiting the highmountainous areas of Mexico is poorly known. Cloacal(body), air, and substrate temperatures were recorded forsix species of montane Crotalus from the Mexican statesof Durango (C. lepidus maculosus), Coahuila (C. p.miquihuanus), Nuevo León (C. p. miquihuanus, C. l.morulus), México (C. triseriatus triseriatus), Michoacán(C. tancitarensis, C. t. triseriatus), and Morelos (C.transversus, C. t. triseriatus). Data were recorded on apopulation of C. l. morulus and C. p. miquihuanus fromPeña Nevada, Nuevo León, over a two year period.Correlations between body temperature and airtemperature, and body temperature and substratetemperature, for active snakes of each taxa (sample sizepermitting) were analyzed and the results presented. Thetime of each observation was also recorded. Significantlinear relationships between body temperature and airtemperature and between body temperature and substratetemperature were present for most taxa. However, in afew species, only the regression of body temperature onsubstrate temperature was statistically significant. Thisdisparity may be attributed to environmental conditionspresent at the collecting sites. In addition, although asignificant linear relationship exists between bodytemperature and air temperature and between bodytemperature and substrate temperature in both species ofmontane Crotalus from Peña Nevada, C. p. miquihuanusappear to be active for a longer period of time over awider range of temperatures.Bush, Sean P. Department of Emergency Medicine,Loma Linda University School of Medicine, Children’sHospital & Medical CenterPre-hospital, first aid and field considerations inrattlesnake bite:The factors that most reduce snakebite-related injury andmortality in the US are rapid transport, intensive care,and antivenom. All patients with rattlesnake bitesshould be transported to the hospital as expeditiously assafely possible. En route, constricting rings, jewelry,and clothing should be removed; the border ofadvancing swelling should be marked and timed; anintravenous fluid bolus should be given; airway supportmay be necessary. All hospitals should stock at leastenough antivenom to treat one patient (although thisshould be confirmed ahead of time if possible). The21

following measures are not recommended for first aid:incision, suction, tourniquets, electric shock, ice directlyon wound, NSAIDS (e.g., aspirin, ibuprofen), alcohol orfolk therapies. Snakebite suction devices don’t removevenom—they just suck. The Sawyer Extractor Pumpremoves only minute quantities of venom and can causeadditional injury after rattlesnake envenomation.Insufficient evidence exists for splinting and/orpositioning (e.g., above or below the heart). Pressureimmobilizationresulted in significantly longer survival,but higher intracompartmental pressures after artificial,intramuscular C. atrox envenomation in an animalmodel. While it’s not recommended widely, certainscenarios may warrant its use. Once pressureimmobilizationis placed, it should not be removed untilantivenom is infusing because of a potential bolus effectafter its removal. It is difficult to predict snakebiteseverity at the time of the bite, but certain factors mayreflect increased likelihood of a more severeenvenomation: large snake size, dangerous snakespecies, small patient size, prolonged fang contact,previous snakebites (treated or not) or exposures tosnakes, or delays to medical care. Individuals withprevious exposure to snakes or venom (i.e., via injection,ingestion or inhalation) should consider the risks,benefits and alternatives of carrying injectableepinephrine in case of immediate, severe allergicreaction. Antivenom may be stable enough to carry inthe field, but it’s probably cost prohibitive to do so andside effects may make it dangerous to infuse in thissetting. Although it may be helpful for medicalpersonnel to identify the species of snake, transportingit (alive or dead) is discouraged because of inherentdangers; digital or Polaroid photography is preferred.On scene, snakes should be only be moved or containedif absolutely necessary; a snake hook or long shovel maybe helpful to move snake into a large, empty trashcanister. Some snakebites may be prevented byprotective clothing, such as boots, chaps, gaiters or evendenim jeans. Keepers of venomous snakes should havea contingency plan in case of snakebite. Have a partnerwhen venturing into snake country or working withdangerous snakes. Circumstances may necessitatehiking out of a wilderness setting. Meanwhile, the bestfirst aid for snakebite is a cell phone and a helicopter.Bush 1 , Sean P., Steven M. Green 1 , Torrey A. Laack 2 ,William K. Hayes 1 , Michael D Cardwell 1 , David A.Tanen 3 . 1 Department of Emergency Medicine, LomaLinda University, School of Medicine & MedicalCenter, Loma Linda, 2 California Division of MedicalToxicology, 3 Department of Emergency Medicine,University of California at San Diego Medical Centerand California Poison Control System, San Diego,CaliforniaPressure-Immobilization Delays Mortality andIncreases Intra-compartmental Pressure afterArtificial Intramuscular Rattlesnake Envenomationin a Porcine ModelWe determined the effect of pressure immobilization onmortality and intracompartmental pressure after artificialintramuscular Crotalus atrox envenomation in a porcinemodel. We prospectively studied 20 pigs using arandomized, controlled design. After anesthesia, C.atrox venom (20 mg/kg) was injected with a 22-gaugeneedle 10 mm deep into the tibialis anterior muscle ofthe hind leg. Pigs were randomized to receive eitherpressure immobilization (applied 1 minute afterenvenomation and maintained throughout the duration ofthe experiment) or no pressure immobilization. Wemeasured time to death, intracompartmental pressurebefore venom injection and at 2 hours after injection,and leg circumference at a standardized location beforeinjection and immediately postmortem. Duration ofsurvival was compared using Kaplan-Meier survivalanalysis. The dose of venom resulted in 100%mortality.The median survival was longer in the pressureimmobilization group (191 minutes, range 140 to 240minutes) than in the control group (median 155 minutes,range 119 to 187 minutes). The difference between thegroups was 36 minutes (95% confidence interval [CI] =2 to 64 minutes; P = 0.0122). The mean (± SD)intracompartmental pressures were 67 ± 13 mm Hg withpressure immobilization and 24 ± 5 mm Hg withoutpressure immobilization. The difference between groupswas 43 mm Hg (95% CI = 32 to 53 mm Hg). The meancircumferences were 14.3 cm in the pressureimmobilization group and 19.1 cm in the control group.The difference between groups was 4.8 cm (95% CI =5.7 to 3.9 cm). Compared with control animals withouttreatment, the pressure immobilization group had longersurvival, less swelling, and higher intracompartmentalpressures after artificial, intramuscular C. atroxenvenomation in our porcine model.Bushar 1 , Lauretta M., Howard K. Reinert 2 , Alan H.Savitzky 3 . 1 Department of Biology, Arcadia University,450 S. Easton Road, Glenside, PA 19038, 2 Departmentof Biology, The College of New Jersey, P. O. Box 7718,Ewing, NJ 08628-0718, 3 Department of BiologicalSciences, Old Dominion University, Norfolk, VA23529-0266.Isolation and reduced genetic variation in the TimberRattlesnake, Crotalus horridus, of the New JerseyPine BarrensThe Timber Rattlesnake, Crotalus horridus, isendangered or threatened in most northeastern states,and its range is highly fragmented compared to historicinformation. In southern New Jersey, the remainingpopulations of C. horridus exist in

Plain. The nearest extant populations to the north andeast are on the Appalachian Mountains in northern NewJersey (~150 km) and Pennsylvania (~150 km). Thenearest extant population to the south is on the AtlanticCoastal Plain of Virginia (~300 km). We usedmicrosatellite analysis to study the population geneticstructure of C. horridus in the Pine Barrens of NewJersey. We compared these populations with the nearestextant populations to the north, west, and south. Ourdata show that the Pine Barrens populations (1) are moreisolated from each other than expected based on thegeographic distance between the populations, and (2)have lower levels of genetic variability than their nearestneighbors. The isolation of these populations increasesthe likelihood of further reduction of genetic variation inthe future. The origin and affinities of the Pine Barrenspopulations have been questioned because of theirintermediate morphological and behavioralcharacteristics relative to Appalachian Mountain andAtlantic Coastal Plain populations. Our data indicate thatthe current Pine Barrens populations have a closergenetic affinity to montane populations in Pennsylvaniaand northern New Jersey than to coastal populations ofVirginia. Although this finding does not allow adefinitive conclusion regarding the origin of the PineBarrens population of C. horridus, our results clearlyindicate that existing Pine Barrens populations arecurrently suffering from isolation, fragmentation, andloss of genetic diversity. Such conditions will likelyresult in further population decline and an increased riskof extirpation.Cardwell, Michael D. 3150 Prince Henry Drive,Sacramento, CA 95833Habitat Utilization and Behavior of the MojaveRattlesnake (Crotalus scutulatus scutulatus) in thewestern Mojave DesertRadiotelemetry resulted in 3,777 observations of 19Crotalus s. scutulatus (9%/10&) over 39 months increosote bush (Larrea tridentata) scrub at an elevationof ca. 975 m in California’s Mohave Desert. Burrowsutilized on 819 occasions when specimens wereunderground during the active season (ca. March –October) included Dipodomys sp. and/orAmmospermophilus leucurus (92%), Vulpes macrotis(5%), Spermophilus beecheyi (1%), and burrows ofundetermined origin (2%). Thirty-seven winter refugeselections by 17 specimens (8%/9%) were documented,including 27 (73%) Dipodomys and/orAmmospermophilus burrows, 7 (19%) Vulpes burrows,2 (5%) in unidentified burrows under a collapsed Joshuatree (Yucca brevifolia) and 1 (3%) Spermophilus burrow.No evidence of communal denning, either withconspecifics or other species, was detected. Of 10specimens (5%/5&) monitored through multiple winters,one (Css61%) occupied the same burrow during twowinters and two (Css03% and Css24&) spent winters inburrows used during previous winters by otherspecimens (Css16& and Css25%, respectively). Severalanimals made late season visits to their own prior winterrefugia before becoming inactive in other nearbyburrows. Woodrat (Neotoma lepida) middens and nearbygranite rock outcrops were ignored in all seasons.Utilizing only specimens with > 365 d continuous data(mean 745 d; range 370-953), males were found tooccupy much larger areas than females (P = 0.001).Mean home ranges, computed by the 95% fixed kernelmethod, were 20.4 ha (SE = 2.59) for males (n = 6) and2.2 ha (SE = 0.43) for females (n = 8). A bimodalmating pattern was observed, with 11 pairs involved inaccompaniment, courtship and/or coitus observed insummer/fall (August, September, October) and 14observed in spring (March, April, May). Observed preyspecies included Dipodomys sp. Perognathus sp.,Ammospermophilus leucurus, and Cnemidophoroustigris.Cardwell, Michael D. 1 , Sean P. Bush MD 2 and RobinT. Clark. 2 1 3150 Prince Henry Drive, Sacramento, CA95833 USA; 2 Department of Emergency Medicine,Loma Linda University Medical Center, 11234Anderson Street, Loma Linda, CA 92354 USA.Males biting males: does testosterone shape bothsides of the snakebite equation?We correlate snakebite epidemiology recorded at amajor southern California trauma center withexaminations of the biting snakes and observations ofsurrounding wild rattlesnake populations. Of the 78rattlesnake bites presenting in 2003 and 2004, 83% (n =65) were male patients. 81% (n = 63) of all bites were tothe hands and/or forearms. Although more malessuffered hand/forearm bites, the difference betweensexes was not significant (P = 0.342). Most bitesoccurred in May (n = 17), June (n = 13), August (n = 11)and September (n = 11). A nearby 4-year field study ofMohave rattlesnakes (Crotalus scutulatus) hasestablished a bimodal mating period (March/April/Mayand August/September/October). During these monthsin 2003 and 2004, mean daily movement of maleMohave rattlesnakes (47 meters/day, SE = 6.93) wasmore than 3 times greater than the mean daily movementof females (14 meters/day, SE = 2.36) (P = 0.001).Similarly, the mean home range utilized by maleMohave rattlesnakes (20.4 hectares, SE = 2.59) wasnearly 10 times greater than that utilized by females (2.2hectares, SE = 0.43) (P = 0.001). Data for otherrattlesnake species responsible for the trauma center’sbites (C. helleri, C. ruber, C. atrox, C. cerastes) alsosuggest that males are much more motile than femalesduring their mating seasons. Of the 12 rattlesnakesresponsible for bites and for which sex could bedetermined, excluding neonates, 83% (n = 10) were23

determined to be males (P = 0.039). We conclude thatmale rattlesnakes are more likely than females to bitehumans at least partly because mature male rattlesnakesare far more active than females during their matingseasons and, therefore, encounter humans morefrequently. Consistent with previous investigators, weconclude that male humans are more likely to be bittenby rattlesnakes than females, probably because theymore often choose to interact with the snakes. Our study,while limited by small sample sizes, suggests that theseverity of a snakebite season may be predictable as thefactors that stimulate rattlesnake sexual behavior arebetter understood.Carmichael, Robert L. Wildlife Discovery Center atElawa Farm, 1401 Middlefork Drive, Lake Forest, IL60045.The grass is rattling: a grass roots conservationeducation program to bring public awareness aboutrattlesnakes and their importance to the environmentWith a grant from TAP Pharmaceuticals, the WildlifeDiscovery Center (WDC) is designing a curriculum formiddle school students that will teach natural history andconservation of rattlesnakes in general and featuring theEastern Massasauga as the focus conservation animal.The WDC is located next to the Middlefork Savanna, thefinest example of a black soil, tall grass savanna in theU.S. The WDC is completing a TC-VES to determinethe presence of Sistrurus catenatus which provided theimpetus for this program. The “Grass is Rattling”program will connect middle school students with theplight of rattlesnakes in general and the easternmassasauga as the primary case study component.Students will learn about the research that is currentlytaking place involving crotalines, and, they will evenincorporate this learned knowledge by applying GPS,radio telemetry, and pit tagging devices in the field.This program is scheduled to begin in the spring of2005. Students will spend time in the field and insidethe WDC where they will go through various stationsand inquiry-based simulations. The highlight of thisprogram will provide students with close up encounterswith the resident rattlesnakes that live in the WDC thatare used for public display and education. We will touchon how the WDC properly cares for an extensivecollection of crotalines that will further enhance thebasic understanding of their natural history. Thelearning experience will be extended beyond theprogram through teacher resource handouts and aninteractive website that will include professionalherpetological contributions and giving students andteachers the ability to track radio tagged snakes.Conservation education is the primary focus of thisprogram, however, it is our hope that future biologistsand herpetologists will be cultivated from this lifechanging program.Clark, Rulon W. Department of Ecology andEvolutionary Biology, Cornell UniversityThe use of fixed videography to monitor rattlesnakepredatory behaviorThe secretive and cryptic habits rattlesnakes make itdifficult to collect information on many aspects of theirnatural history. Although the use of radio telemetry hasprovided a means by which individuals may be reliablyrelocated for observation, it can still be infeasible todirectly observe rare (but critical) events, such aspredatory encounters. For this reason, most informationavailable on rattlesnake natural history comes fromanecdotal observations or laboratory experiments.However, because most rattlesnakes use an ambushstrategy to capture their prey, it is possible to usemodified video equipment to continuously monitor freerangingsnakes at natural ambush sites, thus collecting alarge body of information on foraging behavior. Iillustrate the use of this technique to study timberrattlesnakes (Crotalus horridus), and summarize keyinformation on their rate of prey encounters, successfulattacks, and site residence time. The resultantquantitative information is not only invaluable for adetailed understanding of the natural history anunderstudied group of widespread, top-level predators,but also can be used to inform a variety of ecologicaland physiological models.Clucas 1 , Barbara, Matthew P. Rowe 2 , and Donald H.Owings 1,3 . 1 Animal Behavior Graduate Group and3 Psychology Deparment, University of California, Davis,One Shields Avenue, Davis, CA 95616, 2 Department ofBiology, Appalachian State University, 572 RiversStreet, Boone, NC 28608.Sheep in wolves’ clothing?: Snake scent applicationin ground squirrelsChemical substances produced by one species aresometimes found on the integument of another species.In certain cases, animals acquire the interspecificmaterial by self-application. For example, we havefound that several species of ground squirrels(Spermophilus spp.) self-apply rattlesnake (Crotalusspp.) odors. Specifically, squirrels chew on rattlesnakesubstances (e.g., shed skins) and lick the masticatedmixture onto their fur. The function of such ‘snake scentapplication’ behavior may be part of the coevolvedpredator-prey relationship between rattlesnakes andground squirrels, an ancient interaction that hasgenerated several specialized defense mechanisms in thesquirrels (e.g. venom resistance, risk-sensitiveharassment strategies). The function of snake scentapplication, however, remains to be tested. We proposeseveral hypotheses for why ‘wearing’ snake scent maybe beneficial for ground squirrels, and how snake scentcould either mask ground squirrel odor or exploit fear ofrattlesnakes in conspecifics or heterospecifics. We24

present results from studies on California groundsquirrels (S. beecheyi) and rock squirrels (S. variegatus),which were tested with shed skins from Northern Pacificrattlesnakes (C. viridis oreganus) and Westerndiamondbacks (C. atrox), respectively. Both groundsquirrel species engaged in snake scent applicationbehavior. However, we found individual, population andspecies differences in the propensity of applicationbehavior, and discuss the presumed function(s) of snakescent application in light of this variability.Cobb 1 , Vincent A. and Charles R. Peterson 2 .1 Department of Biology, Middle Tennessee StateUniversity, Murfreesboro, TN 37132, 2 Department ofBiological Sciences, Idaho State University, Pocatello,ID 83209.Thermal ecology of hibernation in the Great BasinRattlesnake (Crotalus oreganus lutosus)Although many species of snakes spend a considerableamount of time hibernating, surprisingly little is knownabout body temperature (T b ) selection during this period.To measure T b variation and associated movementsduring hibernation, we surgically implanted temperaturesensitiveradiotransmitters into 21 adult Great BasinRattlesnakes (Crotalus oreganus lutosus) over a threeyearperiod. All snakes were captured and released at alarge den site in the desert on the Idaho NationalEngineering and Environmental Laboratory insoutheastern Idaho. Body temperatures were measuredonce per week and environmental temperatures weresampled continuously using thermocouples and adatalogger. Snake entrance into the hibernaculumranged from October 3 to November 15. Mean T b ’sdecreased from approximately 13/C in mid November toa minimum of 6/C in February through April and thenincreased to 8/C near emergence time in May. Thelowest T b experienced by any of the snakes was 4.2/C.During the winter, differences in T b ‘s among individualsmeasured at the same time were as great as 5/C. Year toyear variation in overall hibernation T b was less than0.5/C ( = 9.3/C). Although we could not see the snakesin hibernation, radiotelemetry allowed us to determinethe x, y coordinates of individuals. Undergroundmovements by snakes continued until January and, bymid winter most snakes had become relatively stationaryapproximately 10 m back from the den entrance.Movements from January through April were minimaluntil near emergence time. Hibernation emergencetimes varied from April 27 to June 15 with the majorityof snakes exiting in mid May. Durations of hibernationvaried from 189 to 253 days. Considerableinterindividual variation in T b ’s, undergroundmovements, and durations of hibernation suggest thatoverwintering in snakes is more than just a period oflethargy at low temperatures.Cochran, Philip A., Biology Department, Saint Mary’sUniversity, 700 Terrace Heights, Winona, MN 55987Phenology of the Timber Rattlesnake in SouthernMinnesota: Implications for ConservationTimber rattlesnakes in southern Minnesota hibernate indens associated with rock outcrops high on south orsouthwest slopes of bluffs. Most often the hibernaculaare found in or near “goat prairies.” Gravid femalesremain at dens or in nearby rocky habitat, whereas malesand nongravid females disperse during the summer andmay end up at lower elevations. Concern about loss ofgoat prairies through succession has spurred efforts toremove invasive shrubs and trees via cutting orcontrolled burns. Because logistical considerations limitburning to spring or autumn, it is important tounderstand the timing of when snakes enter and leaveparticular dens, including variability among and withinpopulations. Although this study focused on thephenology of timber rattlesnakes at one den during theperiod 2000-2004, supplemental data were collected onseveral other bluffs. Snakes were first observed in mid-May, but earlier dates have been reported by otherworkers. During most years, snakes were last seen inlate September, although in one year they were observedat one den site until October 10. Direct observation ofneonates and indirect evidence from the timing ofshedding indicated that births occurred from late Augustuntil late September, but most young were born duringa two-week period that varied among years from the firstand second weeks of September to the second and thirdweeks. Both adults and neonates were observed aboveground even after heavy frosts. Snakes were observedat lower elevations primarily from early July until earlySeptember, but a few records occurred as late as earlyOctober. Goat prairies should not be burned after April15 or before October 15. Trail maintenance in lowlandareas used by timber rattlesnakes, if it must occur duringthe warm season, should be concentrated in May orJune.Cole, Tim Austin Reptile Service 4500 Williams Dr.Ste. 212-113, Georgetown, Texas 78628Color/pattern morphs in rattlesnakes with emphasison Central Texas atroxThis will be an overview of color/pattern morphs ofCrotalus with known origins . These will consist ofalbinos, melanistic, hypomelanistic and unusual patternmorphs. These may be due to gene mutations orenvironmental issues. I will definitely be raising morequestions than answering them! Several types of albinogenes exist and some are not compatible with each other.Some are possibly sex linked such as the patternlessatrox morph. Some colors may be environmentallylinked to minerals, altitude, or seasonal activities. I amnot going to explain them but show examples of these25

animals with emphahsis on Central Texas specimens ofpatternless atrox, albino atrox, and hypomelanistic atrox.Dart, Richard C. Rocky Mountain Poison and DrugCenter, Denver Health and Department of Surgery(Emergency Medicine), University of ColoradoResearch Needs in Snake Envenomation:It has been over 100 years since the advent of antibodytherapy for envenomation. Building on the work ofSewall, Calmette, Brazil and many others, a remarkablebody of knowledge has been developed. Despite theadvances, the need for research on the treatment ofsnakebite has never been greater. Using clinical cases toillustrate, the presentation will focus on research needsof assessing and treating the snakebite patient. Somepatients develop injury immediately after snakebite,while others may have delayed onset of effects. What isthe cause for these variable courses? Is it the absorptionof venom? Why do some patients bitten by a species likethe Timber rattlesnake or Southern Pacific rattlesnakerespond to antivenom, but others respond only partially?Does this manifestation occur in all species, but researchhas been insufficient to detect it? A major source ofclinical concern (and medical malpractice claims) iscompartment syndrome. The data available seem to leadto opposing conclusions. How can this controversy besolved? The pharmacy acquisition cost of a course ofCroFab is $10,000 to $20,000. Why is antivenom soexpensive? Are there equally effective, but lessexpensive ways of using the antivenom? Is antivenomreally the best approach to treating some manifestationsof snakebite? Many antivenom products contain Fab 2instead of Fab alone. Is this a better choice? Why do wetreat the victim of crotaline snakebite? What are wetrying to achieve? At one time, improved survival wasadequate and this is how manufacturers of antivenomtest their products. However, most clinical concerns inthe United States arise from the local tissue effects ofvenom. Recent evidence suggests that we don’tunderstand well the true outcome of snakebite. Crotalinesnake venom effects are tremendously variable anddiverse. Interpreting the data available and planningfuture research to answer these questions require acoherent and comprehensive approach. Do animalstudies adequately address clinical issues in humans?Many extrapolations are made, are they clinicallyuseful? We need to define our thinking about venomcomponents in pharmacokinetic and pharmacodynamicterms. This leads to the conclusion that there aredifferent “compartments” in crotaline snake venompoisoning, which must be addressed independently.Central effects like coagulopathy are different than localeffects like swelling and hemorrhage. Taking thesediverse research issues into consideration, several largerstrategic issues emerge. A new paradigm is needed tounderstand and investigate the clinical effects of snakevenoms. As importantly, an effective clinical network isneeded to document the clinical presentation and courseof patients as well as study the effects of interventionssuch as first aid measures, drugs and antivenoms.De Lisle, Harold F. Joshua Tree National Park,Twentynine Palms, CA 92277Sharing the resource – Six species of rattlesnakes inJoshua Tree National ParkThe competitive exclusion principle would seem toapply to six species of the single genus Crotalus, feedingmostly on small mammals. In Joshua Tree NationalPark, California, six species of rattlesnakes are found inan area of just 400,000 ha. A pattern noted in ecology isthat diversity at one level begets diversity at other levels.Almost 70 years’ locality data combined with presentfield research was used to test the hypothesis that theserattlesnake species mostly avoid the competitiveexclusion principle by microhabitat differences withinthe great diversity of ecological communities in the parkThese long-term records may also indicate that thedynamics of the desert ecosystem may be changing,possibly the result of climate change and/or localurbanization. Ecological theory predicts that species inecological communities can coexist only if there aredifferences in the responses to limiting resources.Dreslik 1 , Michael J., Thomas G. Anton 2 , Christopher A.Phillips 1 , David Mauger 3 , Thomas P. Wilson 4 , Donald B.Shepard 5 , Alan Resetar 6 , and Benjamin C. Jellen 7 .1 Illinois Natural History Survey, Center for Biodiversity,607 East Peabody Drive, Champaign, IL 61820, USA,2 The Ecological Consulting Group, 800 Oak Street #3B,Winnetka, IL 60093, USA, 3 Forest Preserve District ofWill County, P.O. Box 1069, Joliet, IL 60434, USA,4 University of Tennessee, Tennessee AquariumResearch Institute, Department of Biological andEnvironmental Sciences, Chattanooga, TN 37403, USA,5Sam Noble Oklahoma Museum of Natural History,University of Oklahoma, 2401 Chautauqua Avenue,Norman, OK 73019, USA, 6 Field Museum, Division ofAmphibians and Reptiles, 1400 South Lakeshore Drive,Chicago, IL 60605, USA, 7 Western PennsylvaniaConservancy, 209 4 th Avenue, Pittsburgh, PA 15222,USA.Monitoring the Continuing Decline of the EasternMassasauga (Sistrurus catenatus) in Illinois.Once a widely distributed species in Illinois, the easternmassasauga (Sistrurus catenatus) has been in declinesince the early 1860s. In 1994, S. catenatus was affordedprotection as an Endangered Species in Illinois. Asurvey of historic populations found 19 valid localitiessupported with museum specimens or live captures.Only eight counties (Clinton, Cook, Knox, Lake,Madison, Piatt, Warren, and Will) had potentially extantpopulations as of 1998. The status of the populations in26

Knox and Warren counties remains unknown. Limitedsurveying has revealed the Madison County populationas extant. Intensive surveying in Clinton, Cook, Lake,Piatt, and Will counties over the last decade haverevealed that one of these populations faces imminentextirpation, one is potentially extirpated, and two arestable with low population sizes. Only one population,Clinton County, may be viable.Dugan, Eric A. and William K. Hayes. Department ofNatural Sciences, Loma Linda University, Loma Linda,CA, USA.Comparative Ecology of Red Diamond (Crotalusruber) and Southern Pacific (Crotalus helleri)Rattlesnakes in southern CaliforniaHabitat utilization, home range size, diet, and matingphenology were compared between sympatricpopulations of Crotalus ruber and C. helleri. Data willbe presented from the first two years of an on-goingradio telemetry project in the Chino Hills State Park.Home range size differences approached statisticalsignificance (p= 0.06), with C. helleri occupying morearea. Limited overlap of diet was observed between thetwo species. Crotalus ruber feeds predominately onlarger (150-1000g) prey species (Citellus, Neotoma,Sylvilagus), whereas C. helleri was observed feeding onsmaller (20-150 g) prey items (Microtus, Thomomys,Perognathus). Among the five habitat types occurringat the study site (cactus patches, coastal sage scrub, oakwoodland, riparian, and non-native grassland), C. helleriutilized primarily the non-native grassland and riparianareas, whereas C. ruber preferred the cactus patches andcoastal sage scrub. Movement data revealed a peak inactivity during both spring and fall for C. helleri, likelydue to a bi-modal reproductive cycle for this species. Incontrast, the activity of C. ruber peaked only in thespring, coinciding with its unimodal mating phenology.Radio-telemetry revealed a high predation rate for C.helleri and a low predation rate for C. ruber, likelyattributable to differences in life histories of the twospecies. Considering only telemetered snakes, 55% ofC. helleri were predated, compared to 0% for C. ruber.Results from the first two years shows limited nicheoverlap during the active season (Mar.-Nov.), withincreasing overlap of habitat utilization during thenon-active season (Dec.-Feb.).Ehret, Suzanne, Matt Goode, Dave Prival, and MelissaAmarello, School of Natural Resources, University ofArizona, 104 Biological Sciences East, Tucson, AZ85721Ecology of Banded Rock Rattlesnakes (Crotaluslepidus klauberi) in the Chiricahua Mountains ofsoutheastern ArizonaWe conducted a long-term mark-recapture study of apopulation of Banded Rock Rattlesnakes (Crotaluslepidus klauberi) in the Chiricahua Mountains ofsoutheastern Arizona. In 1999, and from 2002-2004, wecaptured, measured, and marked 132 individual snakes,49 of which we recaptured a total of 73 times. Due tohigh recapture rates, we were able to obtain populationdensity estimates with relatively small confidenceintervals, which is unique for snakes. We also examinedpopulation structure, movement patterns, habitat use,growth and reproduction. Banded Rock Rattlesnakes area protected species in Arizona. Threats include illegalcollection for the pet trade, and destructive wildfirescaused by long-term fuel buildup associated with firesuppression. In the future, we plan to use our data toinvestigate the effects of fire on Banded RockRattlesnakes by comparing them with post-burn data.Farrell, Terence M., Peter G. May, and Melissa A.Pilgrim. Department of Biology, Stetson University,421 Woodland Avenue, DeLand, FL 32720.Annual Variation in Yearling Recruitment to aPopulation of Sistrurus miliariusMost northern rattlesnake populations exhibit unstablepopulation dynamics that are driven by large annualvariation in reproductive output. Population dynamics,however, are poorly understood in species living inwarmer, less seasonal environments. We studied apopulation of pigmy rattlesnakes for nine years (1992-2000) using mark-recapture techniques and temporaryhousing of pregnant females in field enclosures todetermine how variation in several demographicparameters influences the number of successful neonatesthat entered a population. Annual yearling recruitment(the number of one year-olds entering the population)was the product of five demographic traits: 1) thenumber of number of adult females in the population, 2)the proportion of adult females that were pregnant, 3)the mean number of viable offspring per litter, 4) theproportion of neonates that survived birth, and 5) theproportion of neonates that survived for one year. Somedemographic traits, including mean number of offspringper litter and the mean proportion of viable young,exhibited little variation among years. Otherdemographic traits, including the number of adultfemales in the population, the proportion of adultfemales that were pregnant, and the annual neonatesurvival, exhibited high annual variation. Furthermore,variation among key demographic traits often exhibitedpositive covariances that caused the annual variation inyearling recruitment to be much higher than thevariation observed in any single demographic trait.Yearling recruitment was five times higher than in themost successful years compared to the years with lowestrecruitment. The large variation in populationrecruitment observed in this small rattlesnake speciesinhabiting a warm temperature climate is similar to that27

observed in large, cool temperate species and has strongimplications for conservation.Figueroa, Alex, Eric A. Dugan, and William K. Hayes.Department of Natural Sciences, Loma LindaUniversity, Loma Linda, CA 92350 USABehavioral ecology of neonate Southern PacificRattlesnakes (Crotalus helleri) in southern CaliforniaThe goals of this study were to design a method for thesuccessful application of radiotransmitters to neonatesouthern Pacific rattlesnakes, Crotalus helleri, and toexamine the ecology of this specific age-class.Currently, very little is known concerning the ecology ofneonate snakes. Radiotransmitters (SOM-2011, 0.6 g,1.4g, and 2.0 g Wildlife Materials, Inc., Canada) wereattached externally to neonate snakes on the posteriorportion of the body, at approximately 75% of the snake’ssnout-vent length (SVL), using a super glue adhesive.Weight of the transmitter package surpassed 5% but didnot exceed 10% of the snakes body mass; no obviousbehavioral impairment was noticed. Larger-sizedtransmitters were used for their longer battery capacityto extend radiotracking periods. Neonates preferredmicrohabitats that were structurally dense in cover andcontinuous. Neonates were successful at foraging, asdemonstrated by rattle segment development (associatedwith ecdysis), visual observations of food boli, and gainin mass. Neonates generally moved in a linear positionwith movements being greater in September indicatingdispersal from the natal area. Snakes are also capable oflarge moves, with one particular snake moving 61 m inone day. Snakes were often observed in shrubs up to 90cm above the ground in apparent foraging positions,where lizards are also frequently seen. All snakes whosetransmitters remained intact survived into the winter;however, it is yet unknown whether neonates hibernate,as they remained active into December and exhibited alonger active season than C. helleri adults in the samearea. We suggest that external attachment may be aviable, less invasive method of radiotracking neonatesnakes.Fogell, Daniel D. and James D. Fawcett. Department ofBiology, University of Nebraska at Omaha, 6001 DodgeSt., Omaha, NE 68182-0040.Ecology and Conservation of the Timber Rattlesnake(Crotalus horridus) in NebraskaThe timber rattlesnake (Crotalus horridus) reaches thenorthwestern periphery of its distribution in southeasternNebraska. Several historic populations have beenextirpated as a result of anthropogenic habitatmodifications, however a few populations still exist infragmented locations along the extreme southeasternborder. In 1998, a study was initiated to investigate thenatural history, distribution, and habitat preferences ofC. horridus in southeast Nebraska. The study includeda single year of radiotelemetry as well as multipleseasons of demographic, reproductive, and distributiondata acquisition. In Nebraska, timber rattlesnakes utilizerocky outcrops as winter hibernacula, which are thehabitat features that limit further distribution in the state.Snakes den communally, however dens are small and thenumber of individuals per den is low. Habitat usedduring the active season includes riparian woodlands,secondary growth forest, grassland, and row-cropagricultural fields. The active season lasts an average of179 days during which three significant migratorymilestones take place. The mean migratory distance is3.4 km. The difference in migratory distances betweenmales and non-gravid females was significant, howeverthe difference between non-gravid and gravid femaleswas not. Reproductive activity is limited to the latterhalf of the active season, with breeding activityoccurring throughout mid- to late summer andparturition taking place during early fall of the followingyear. Population size structure follows a normaldistribution. Sexual dimorphism was evident for twocharacteristics – size (SVL) and tail length – with malesbeing significantly larger than females. Timberrattlesnakes in Nebraska face several threats to theircontinued existence including habitat conversion, humanpersecution, and the lack of protected refugia, howeverthe most immediate threat is the succession ofconiferous woody vegetation at denning locations.Recent actions by the Nebraska Game and ParksCommission have addressed this issue by providinglandowner incentives to remove invasive trees.Fogell, Daniel D. Southeast Community College,Academic Education Division, 8800 ‘O’ St., Lincoln,NE, 68520.Status of the Prairie Rattlesnake (Crotalus viridis) inthe Loess Hills of Northwest IowaThroughout most of their range, prairie rattlesnakes(Crotalus viridis) are fairly common as short- to mixedgrassprairie inhabitants, utilizing rocky outcrops and, insome cases, prairie dog (Cynomys ludovicianus) burrowsfor winter hibernacula. Much of this habitat iscontiguous throughout the northern Great Plains,however in northwest Iowa, northeast Nebraska, andsoutheast South Dakota nearly all of this habitat hasbeen lost to agriculture, woody plant invasion, andurban/suburban development. The extant Crotalusviridis population that resides in the northern Loess Hillsof Iowa likely represents the last viable population ofthis species in Iowa. During 2000 and 2001, a baselinesurvey was conducted to initiate population and habitatmonitoring at The Nature Conservancy’s Broken KettleGrassland Preserve north of Sioux City, Iowa.Additionally a radiotelemetry study was conducted in2000 to assess habitat and spatial requirements. Resultsfrom this study were used to establish conservation28

guidelines for both The Nature Conservancy and theIowa Department of Natural Resources (DNR) to ensurethe continued existence of prairie rattlesnakes innorthwest Iowa and encourage the recolonization ofpreviously populated areas by restoring habitat to predisturbancelevels. Since the completion of this study,The Nature Conservancy has purchased or acquiredcontrol of additional parcels of land that are suitable forprairie rattlesnakes. Additionally, aggressive grasslandand savanna restoration efforts have been started at FiveRidge Prairie State Preserve, which is less than 1.0 kmfrom Broken Kettle and is a historic prairie rattlesnakelocation. These actions may expedite the naturalimmigration and recolonization of prairie rattlesnakes atFive Ridge Prairie.Gennaro, Joseph F., Jr. and Ernest R. Casey, Jr.Department of Anatomy and Cell Biology, College ofMedicine, University of Florida, Gainesville, FL32610Two Neutrotropic Effects of Pit Viper VenomsThe Pupillar Effect: Mammals envenomed by theEastern diamondback rattlesnake (Crotalus adamanteus)or the cottonmouth moccasin (Agkistrodon p.piscivorus) exhibit an immediate but transitory pupillarconstriction. This parasympathomimetic effect ismediated through the ciliary ganglion and can beprevented by a retrobulbar (intraorbital) injection ofanesthetic. The Pulmonary Effect: The venom of thecottonmouth moccasin injected into the dorsal or ventrallymph space of the frog (Rana pipiens) produces animmediate and total constriction of the lung sacs.Applied locally to the surface of the lung, even inminute quantities, it produces a gradual but rapid localconstriction which eventually envelops the entire sac.Tests of venoms and toxins from different sourcessuggest the possibility that the venom moiety whichproduces the pulmonary effect is found primarily, butnot exclusively, in snakes that prey upon frogs. In bothspecies of snakes, the predatory strike is accompaniedby an immediate effect, perhaps mediated by theparasympathetic nervous system, and designed primarilyto incapacitate the prey and facilitate apprehension. Thisprecedes a subsequent one in which digestive enzymesare involved. It is not appropriate at this time toattribute these either singly or together to neurotoxins,since the effect of the former is transitory (and notlethal)and neither has been purified to a single principle thepotency of which can be determined in test animals.Both are produced by the venom moieties which takepart in the securing of the food animal and directlyoppose the sympathetic nervous system "fright-flight"response of the prey to emergency. In doing so theygreatly increase the opportunity for the snake to acquirethe prey animal for ingestion.Gibson, Scott E. and Bruce A. Kingsbury. Departmentof Biology, Indiana-Purdue University, Fort Wayne, IN46805-1499Habitat Use by the Timber Rattlesnake in SouthernIndianaWe used radio-telemetry to explore the spatial ecologyof the Timber Rattlesnake, Crotalus horridus2 in ahardwood forest of southern Indiana. Our intent was toenhance the limited understanding of this species in theMidwest portion of its range. We present here ourfindings with respect to habitat use. Habitat preferenceswere influenced by reproductive condition, ontogeny,and sex, though the most notable differences were due toreproductive status. Gravid females selected sites thatwere less densely forested and thus had less canopyclosure than other snake classes, and frequently utilizedthe inside of large hollow logs as refuge sites. Suchmicrohabitat selection was in sharp contrast to that ofnon-gravid snakes, which were predominately found inclosed canopy forest, and rarely use hollow logs.Differences in microhabitat preferences among nongravidsnake classes were less distinct than thosecompared with gravid females, particularly betweensexes, but variation still did occur. Juvenile snakestended to utilize sites with higher overall structural coverand canopy closure, and positioned themselves in closerproximity to overstory trees and logs than other snakeclasses. In contrast, adult males exhibited highvariability in selection of canopy closure, and generallyshowed less affinity for logs and log cover. Non-gravidfemales primarily selected sites with relativelyintermediate cover, and were found to differ little inhabitat preference from other non-gravid snake classes.Denning sites typically consisted of a series of holesalong rock seams on very steep slopes near ridge tops,often at the head of ravines or drainages. Exposed rockat such sites was considerably less than the talus slopesand outcrops frequently reported as hibernaculaelsewhere in the Timber Rattlesnake's range. However,overall, despite obvious differences in topography andavailable habitat, our findings closely paralleled those ofsimilar studies in the eastern United States.Goode, Matt and Jeffrey J. Smith. School of NaturalResources, 104 Biological Sciences East, University ofArizona, Tucson, AZ 85721Calm before the storm: tiger rattlesnakes and urbandevelopmentAs part of a long-term study on effects of urbandevelopment on herpetofauna near Tucson, Arizona wecaptured 228 tiger rattlesnakes (Crotalus tigris), 46 ofwhich we implanted with radiotelemeters. We trackedsnakes several times per week from 2002-2004 as theymoved throughout the development matrix, utilizingareas associated with a newly constructed golf course.We also tracked several rattlesnakes in nearby29

undeveloped areas, allowing for comparison of a varietyof ecological parameters. Tiger rattlesnakes used golfcourse features, such as tee boxes and irrigatedvegetation along fairways, out of proportion to theiravailability. We documented use of home ranges inareas slated for development, enabling before-aftercomparisons as development proceeds. We alsodocumented mortality of tiger rattlesnakes byconstruction workers. In addition, we discuss our effortsto educate golfers and residents living in the area usinginterpretive signage along the golf course. We will usethe results of our research to develop workshopstargeting golf course designers, supervisors, andmaintenance crews in an effort to make golf coursesmore compatible with herpetofauna.David B. Greenberg. Department of Ecology,Evolution, and Marine Biology, University of California,Santa Barbara, CA 93106, USA.The effects of surface insolation on shelter siteselection by Crotalus mitchellii and C. ruberIn temperate environments, snakes survive extremes oftemperature by taking refuge in insulated shelters. Weknow, for example, that where winters are cold snakeshibernate at sites with deep crevices. These sites aretypically on south-facing slopes, and we assume thesnakes prefer hibernacula with high insolation. Thealleged preference of snakes for shelters with a certainexposure to solar radiation has never been testedquantitatively, however. In this study I test whethersouthwestern U.S. desert rattlesnakes (Crotalusmitchellii and C. ruber), inhabiting a region with mildlycold winters and extremely hot summers, choose a)winter hibernacula with particularly high irradiance andb) daytime shelters in summer with particularly lowirradiance. I computed models of spatial variation insolar irradiance across the study area, used Monte Carlosimulations to estimate the irradiances of shelters chosenrandomly within each snake's potential activity area, andtested for differences between the irradiances ofobserved and randomly-simulated shelters. I predictedthat winter hibernacula would have higher irradiance,and summer shelters lower irradiance, than expected ifsnakes chose them randomly. However the oppositepattern appears: snakes chose winter hibernacula thatreceive less solar radiation, and summer shelters thatreceive more solar radiation, than other sites in theiractivity ranges. It's possible that in regions with onlymild winters, where low temperatures never becomelethal, it's best to be as cold as possible whilehibernating (i.e., at a site with low irradiance); keepingmetabolic rate low may help during several months offasting. As for selection of summer shelters at highirradiancesites, these shelters may be sufficiently deepthat irradiance at the surface has little effect on internaltemperature. In this case, snakes might shelter at highirradiancesites because the surface above will bewarmer at night when they become active.Halama 1 , Kenneth J., Adam J. Malisch 1,2 , TracyTennant 1 , Michael Aspell 1 , and John T. Rotenberry 1,2 .1 Center for Conservation Biology and 2 Department ofBiology, University of California, Riverside, CA 92521.Modeling the landscape niche characteristics of thered diamond rattlesnake (Crotalus ruber) utilizing apartitioned Mahalanobis D 2 statistic: implications forbiology and conservation.We model landscape-level niche parameters of the reddiamond rattlesnake (Crotalus ruber), a federal speciesof special concern, in western Riverside County,California. Using current and historical records, we mapknown locations of rattlesnakes into a GeographicalInformation System (GIS), which also contains layersdescribing spatial variation in a number ofenvironmental parameters thought to influence thespecies’ distribution. We use a modification of theMahalanobis D 2 statistic to develop a multivariate modelthat describes combinations of environmental variablesthat are associated with limits to the distribution of thesnake at the landscape level, then use that model todevelop a regional map identifying areas that share thesame configuration of variables as those points known tobe occupied. Variables that seem most closelyassociated with the species’ distribution include lowelevation, high winter precipitation, and the presence ofchaparral, and sage scrub habitat. Future efforts toconserve the rattlesnake in Southern California shouldconsider established reserves and addition areas wherethe species’ niche parameters prevail.Hamilton, Bryan. Great Basin National Park, ResourceManagement Branch.Use of solar models and GIS to evaluate potentialhibernacula in the Great Basin Rattlesnake (Crotaluslutosus)Thirty-one communal rattlesnake hibernacula fromNevada (n=6), Utah (n=4), Arizona (n=10), and Ohio(n=11) were spatially examined using GIS. A minimumrange of 2-50 individuals, of four different species,utilized the various hibernacula. Hibernacula wereGPSed and overlain on elevation, slope, aspect, andsolar radiation GIS layers to obtain their respectivevalues and then compared to random points. Nevada,Utah, and Arizona were combined for analysis becauseof their ecologic and geographic similarities. Logisticregression indicated that only slope and aspect weresignificant factors for Nevada, Utah, and Arizonahibernacula (p112.530

degrees, and aspect40 degrees, similarmodels may not be suitable at lower latitude, lessmontane regions, where selection for communalhibernacula is not as strong.Hayes 1 , William K., Sean P. Bush 2 , Shelton S. Herbert 1 ,G. Curtis Rehling 1 , Michael D. Cardwell 3 , and Eric A.Dugan 1 . 1 Department of Natural Sciences, Loma LindaUniversity, Loma Linda, CA, USA, 2 Department ofEmergency Medicine, Loma Linda University MedicalCenter, Loma Linda, CA, USA, 3 3150 Prince HenryDrive, Sacramento, CA, USAUSA,Defensive bites by rattlesnakes (Genus Crotalus):Venom expenditure, envenomation severity, and theimportance of snake sizeThis study examined the factors that influence venomexpenditure and snakebite severity during bites athumans. In bites elicited by model human limbs (warm,saline-filled gloves), snake size (partial r 2 = 0.47) andduration of fang contact (partial r 2 = 0.47) werepositively associated with mass of venom injectedduring single bites (N = 23 snakes of the formerCrotalus viridis subspecies). Two of 26 bites (7.7%)were dry. Venom expenditure (mean = 52 mg), durationof fang contact (mean = 0.29 sec), and frequency of drybites (12.1%) were similar for each of three bites insuccession (N = 9 adult snakes). In a retrospective studyof 100 snakebite cases presenting at LLUMC, fivefactors were considered in a general linear modelexploring snakebite severity. Snakebite severity score(SSS) was positively associated with snake size (partial0 2 = 0.41; P = 0.006) and negatively associated withpatient mass (partial 0 2 = 0.33; P = 0.008). Species ofsnake (5 from southern California), site of bite (distaldigit, proximal digit, limb), and number of fang marks (1to 4) were independent of SSS. Snake size was alsoassociated with site of bite (small snakes bit distalregions more often than large snakes; Cramer’s V =0.41, P = 0.003) and patient mass (large snakes weremore likely to bite larger patients; 0 2 = 0.12; P = 0.012).In five cases involving a snake biting twice,envenomation severity was similar for each of the twobites. In a laboratory study, distance between fangs (r 2= 0.79) and puncture wounds (r 2 = 0.74) was stronglyassociated with snake size and the regressionrelationships were statistically similar for five species (N= 78 total). Distance between fang marks can be usefulfor physicians evaluating the potential for envenomationseverity. These findings, particularly concerning theinfluence of snake size, have important implications forunderstanding the behavioral ecology of venomexpenditure by snakes and studies addressing alternativeor supplementary treatments for snakebite.Hayes, William K. Department of Natural Sciences,Loma Linda University, Loma Linda, CA, USA.The snake venom-metering controversy: Levels ofanalysis, assumptions, and evidenceThe question of how snakes allocate their venom haslong fascinated scientists. The amount of venominjected into a target varies with size of snake, context ofthe bite (predatory or defensive), target identity (speciesand size), and a host of other factors. A number ofstudies provide evidence that snakes have the cognitivecapacity to control, or meter, venom expenditure duringboth predatory and defensive contexts. However, arecent paper dismisses the evidence and presents analternative explanation, the pressure-balance hypothesis,which attributes differences in venom expenditure tovariation in strike kinematics and/or target surfacefeatures. As for many conflicts in science, thiscontroversy arises largely because two hypotheses arepitted against each other (venom-metering and pressurebalance)that represent fundamentally different levels ofanalysis (cognitive and physiological, respectively).Careful analysis of videotaped venom extractionsprovides evidence that crotaline snakes indeed possesscognitive control of venom expulsion, probably vianumerous mechanisms including (but not limited to) jawclosure, fang movements, and force and duration ofgland contraction. A clearer picture of venomexpenditure emerges when the evidence is considered inlight of six hypotheses representing four of the fiverecognized levels of analysis. Specifically, reporteddifferences in venom expenditure could be interpreted asresulting from: 1) venom metering (the snake decideshow much venom to release, a cognitive process), 2)differences in strike kinematics (a physiologicalprocess), 3) differences in target features that mightaffect or constrain the kinematics of venom delivery (aphysiological process), 4) depletion of venom supply insubsequent bites (a physiological process), 5) differencesin snake size (an ontogenetic process), and/or 6) venomoptimization for different targets or contexts (afunctional consequence). Although all of thesehypotheses appear valid, data from individual31

experiments support anywhere from none to four ofthese non-exclusive hypotheses.Ivanyi, Craig S. and Hugh K, McCrystal. Departmentof Herpetology, Ichthyology and Invertebrate Zoology,Arizona-Sonora Desert Museum, 2021 N. Kinney Rd.,Tucson, AZ 85743.Translocation of Venomous Reptiles in Pima County,Arizona: Advice and Consent or Dissent?People of North America have more information aboutsnakes available to them than ever before. Yet, amajority of Americans remain largely ignorant aboutsnake biology and ophidiophobia still ranks as one of thetop phobias worldwide. Even many enlightened peopleare generally uncomfortable with snakes and lizards,especially venomous ones. Though these people may notadvocate killing the animals, most people do not wish toshare their land with these animals. Every year, in theU.S., Canada and elsewhere, thousands of wellintentionedpeople request to have snakes removed fromtheir property. In Pima County Arizona, surrounding thecity of Tucson, fire department rescue companies are themost common agencies asked to perform this service.Personnel from these agencies, which are sworn toprotect their constituents, have been performing thispublic service. For decades, little thought was given towhat affect these translocations had on the animals, thepopulations that they originated from, or those that theywere introduced to. Due to the outcry from snakeconservationists, reptile translocation has been heavilycriticized. In 1998, the authors - in conjunction with alocal herpetological society and the Arizona Game andFish Department - developed a new, more biologicallysound protocol for one of the local fire departments. In2000, Drexel Heights Fire Department adopted thisprotocol and the authors began a training program fordepartment personnel. In 2003, the Drexel Heights FireDepartment became the first fire department in the Stateof Arizona to be granted legal authority from theArizona Game and Fish Department to translocatereptiles. Subsequently, other fire departments haveadopted this new protocol and several of them havereceived training from the authors. In this paper wedescribe the situation in southern Arizona, howvenomous animals have been handled in this area andthe authors’ experience with development andimplementation of snake translocation protocols.Jackson, D. Dewaine. Department of Chemistry,Stetson University, 421 N. Woodland Blvd., DeLand,FL 32723.Proteases and Other Enzymes in Dusky PigmyRattlesnake (Sistrurus miliarius barbouri) venomThe Dusky Pigmy Rattlesnake (Sistrurus miliariusbarbouri) is a small (average adult SVL ~45 cm)venomous snake abundant in the southeast UnitedStates. In central Florida these snakes can be found in adiverse set of habitats including moist forest, dry upland,and floodplain marsh. There are no recorded instances ofhuman death from pigmy rattlesnake bites, although thebite is described as intensely painful. Probably becauseof its seemingly non-threatening nature, the venom ofdusky pigmy rattlesnakes has not been thoroughlyinvestigated. Pigmy rattlesnake venom was subjected toa battery of assays for enzymatic activity. Thevenom exhibited activity for trypsin-like and kallikreinlikeproteases, metalloproteases, phospholipase A 2 ,ATPase, L-amino acid oxidase, phosphodiesterase, andphosphomonoesterase, among others. Assays againstcarbohydrate substrates and for overall venom toxicityare ongoing, but these results indicate (not surprisingly)that the venom of dusky pigmy rattlesnakes containsenzymes that degrade all classes of biomolecules. Astudy has since been initiated to follow potentialontogenic changes in enzyme activities from pigmyrattlesnake venom. Given the pigmy rattlesnake’s smallsize and observed greater dependence (than largerCrotalus rattlesnakes) on ectothermic prey after reachingadulthood, I am very curious to see whether the pigmyrattlesnake’s venom behaves more like that from largerrattlesnakes, for which ontogenic changes in enzymaticactivity and toxicity have been observed, or more likethat from midget faded rattlesnake (Crotalus oreganosconcolor), which showed differences in several enzymeactivities but, surprisingly, no change in venom toxicityplus very low metalloprotease acitivity.Jackson, Kate (University of Toronto) and BruceYoung (Washington State University)Functional specialization of the extrinsic venomgland musculature in crotaline snakes: What is therole of the M. Pterygoideus Glandulae?The extrinsic venom gland musculature in snakesexhibits a reasonably conserved spatial pattern aroundthe venom gland. A prominent exception to this patternis the M. Pterygoideus Glandulae, which originates fromthe surface of the venom gland itself; this muscle is onlyfound in crotaline snakes, and has a spotty distributionwithin that group. Previous workers have proposed thatthe M. Pterygoideus Glandulae represents a muscularspecialization to increase venom expulsion. Here we testthis hypothesis by directly quantifying the relativevenom pressure produced upon stimulation of theindividual extrinsic venom gland muscles of threecrotaline snakes; Calloselasma rhodostoma (where theM. Pterygoideus Glandulae is pronounced), Crotalusatrox (which has a M. Pterygoideus Glandulae), andAgkistrodon contortrix (which lacks this muscle). Ourresults suggest that the M. Pterygoideus Glandulae doesincrease venom expulsion, and that crotaline snakeswhich lack this muscle, like Agkistrodon contortrix,have not compensated in other ways. The key to32

understanding the functional significance of this muscle,and perhaps its phylogenetic development, may simplybe the relative length of this muscle’s courseperpendicular to the venom gland, which is related to thespatial relationship between the venom gland and palatomaxillaryarch in these snakes.Jenkins, Christopher L. and Charles R. Peterson.Herpetology Laboratory, Department of BiologicalSciences, Idaho State University, Pocatello, ID 83204;jenkchri@isu.edu.Linking landscape disturbance to population levelvariation in western rattlesnake life historiesThe synergistic effects of livestock grazing, invasiveplants, and fires are altering the sagebrush steppeecosystems of southern Idaho. This phenomenon ishaving a negative impact on a number of wildlife speciesthat inhabit these systems. Our preliminary results froma 14-year mark recapture data set of three westernrattlesnake populations shows that there is significantgeographic variation in life histories among populations.In addition, we found that these life history differencesare due to variation in the amount of resources snakesare able to acquire during the summer active period. Thegoal of this study is to determine the environmentalfactors that are responsible for the observed life historyvariation. We used radio telemetry to follow 12 snakesin 2003 and 23 snakes in 2004. At each snake locationand a series of random locations, we measured a suite ofhabitat characteristics and trapped small mammals. Wefound that small mammal biomass is associated withhabitat characteristics typical of undisturbed sagebrushsteppe including a positive relationship with shrubheight and biological crust cover and a negativerelationship with grass cover. We also found that thebiomass of small mammals within a snake’s home rangeaccurately predicts how much weight a snake gainsthroughout the active season. The results from this studyled use to develop a conceptual model that ultimatelylinks landscape disturbance to snake life historiesthrough changes in habitat and prey resources. Ourfuture studies will focus more effort on testing thehypothesized links in our conceptual model. This studyreveals that there may be a series of trophic interactionscaused by landscape disturbance that ultimately affectswestern rattlesnakes in sagebrush steppe ecosystems.Jorgensen, Dennis and C. Cormack Gates, Faculty ofEnvironmental Design, University of Calgary, 2500University Dr. NW, Calgary, AB. T2N 1N4.Differential movement patterns among non-gravidfemale prairie rattlesnakes (Crotalus v. viridis) at thenorthern extent of their range.In Alberta multiple land use practices (e.g. grazing,cultivation, oil and gas development, and roadconstruction) have reduced the amount of native prairieby approximately 57% and have fragmented much ofwhat remains. Consequently, highly mobile organisms,such as snakes, are required to travel throughincreasingly heterogeneous terrain to locate resources.Multiple land uses that alter the distribution of foodresources and thermoregulatory cover for prairierattlesnakes across the landscape should influence theirforaging movements. The long distance (up to 25 km),fixed bearing migrations observed among rattlesnakes inAlberta provide a unique context for assessing therelationship between increasing landscape heterogeneity,and individual movement patterns and habitat use. I usedradio-telemetry to monitor the movements and habitatuse of 11 migrating non-gravid female prairierattlesnakes. Locations were recorded at regular intervalsfrom late April to early October 2004. The landscape inwhich these snakes were monitored varied from highnative prairie to highly modified (cultivated). I observedtwo distinct movement patterns. The first movementpattern is consistent with previous observations of longdistance fixed-bearing migrations of rattlesnakes inAlberta. In this case, 4 females left river breaks wheredens occur to forage in upland prairie. Displacement ofsnakes from dens ranged from 3.0 to 10.0 km. Snakesmaintained fixed bearing routes despite encounteringgrazing, cultivation, roads and pipelines, althoughsnakes tended to use available edge habitats in disturbedareas (fence lines and margins of cultivated fields). Thesecond movement pattern was highly tortuous andinvolved shorter displacement from den sites, rangingfrom 0.5 to 2.6 km. Despite not moving as far from dens,the cumulative distances traveled by snakes were similarto those making long-distance migrations from the den.Comparisons of body condition among transmitteredsnakes suggest that females that engaged in longdistancelinear migrations from dens showed greaterimprovement in body condition than those that engagedin tortuous migrations closer to dens. A second fieldseason, including tracking of non-gravid females fromthe first season that remain non-gravid for a second year,will provide further evidence to assess whether twomovement patterns are typical and whether individualsappear to consistently use a specific movement pattern.Jurado 1 , Jennifer D., Eppie D. Rael 1 , Carl S. Lieb 1 ,Sean P. Bush 2 , and William K. Hayes 3 . 1 Department ofBiological Sciences, The University of Texas at El PasoEl Paso, Texas, 79968, 2 Department of EmergencyMedicine, Loma Linda University Medical Center,Loma Linda, California, 92350, 3 Department of Earthand Biological Sciences, Loma Linda University, LomaLinda, California, 92350Inactivation of Complement by Crotalus helleri(Southern Pacific Rattlesnake) VenomC. helleri venom was examined to determine whether allmembers of this species inactivate complement and to33

determine whether a correlation exists betweencomplement inactivation and venom type. Most C.helleri venoms had complement inactivating activity,however inactivation was minimal in some and moderateto strong in others. AF5 antibodies, antibodiesdeveloped against a complement inactivating proteinisolated from C. s .scutulatus (Mojave rattlesnake)venom, generally recognized only C. helleri venoms thathad high complement inactivating activity. Severalvenoms (Venoms Ch5, Ch27, and Ch28) that inactivatedcomplement moderately were not recognized by AF5indicating that there are other complement inactivatingproteins in venom of this species. The datademonstrated an association between venom type andlocality. Venoms with high complement inactivatingactivity were associated with the San Bernardino andSan Gabriel mountain ranges in California, and thesevenoms were all type B venoms (lack Mojave toxin).The venoms that had minimal complement inactivatingactivity were collected in the San Jacinto Mountains inCalifornia and these venoms had Mojave toxin (VenomA). Understanding intraspecific venom variation withinC. helleri could lead to the improved treatment of C.helleri snake bite victims. Additionally, mapping thevenom types will help gain a better understanding of theevolutionary factors that may have influenced thisvariation.Kardong 1 , Kenneth V. and Tamara L. Smith 2 . 1 Schoolof Biological Sciences, P.O. Box 644236, WashingtonState University, Pullman, WA 99164, 2 Center forTeaching, Learning, and Technology, Washington StateUniversity, Pullman, WA 99164.On being a rodent in rattlesnake country: between arock and a hard spotCommonly, rattlesnakes quickly release rodent preystruck from ambush sites. This quick release removesthe snake from possible retaliation by the prey butnecessitates the relocation of the envenomated prey thatdashes off and soon dies. Prominent among the sensorycues used to relocate struck prey are chemosensory cuesproduced by and during the process of envenomationthereby initiating a discrete odor in the struck rodentgiving it a distinctive chemosensory odor used torelocate it. The chemical character of this inducedchemosensory odor is not known, but it is likely relatedto natural pheromones released in a social context byrodents. If so, then rodents are in a curious evolutionarybind. On the one hand, selection favors the presence ofuseful pheromones in mediating successful socialinteractions among rodents in a population. On the otherhand, if this same pheromone is elicited duringenvenomation, then it enhances the success of rodentpredators (rattlesnakes), and with such success (recoveryof prey) encourages rattlesnakes to remain in the vicinityin ambush for more unwary rodents in the localpopulation. Rodents are caught between twocontradictory selective pressures: if predatory selectionfavors reduction in the pheromone, then a means ofsocial interaction suffers; if social selection favorsenhanced pheromone production, then rattlesnakesbecome more effective predators and rodents sufferincreased exposure to such predators.Keyler, Daniel E.. Department of Medicine, HennepinCounty Medical Center & University of Minnesota, 701Park Ave., Minneapolis, MN 55415.Timber Rattlesnake (Crotalus horridus)Envenomations in the Upper Mississippi River ValleyCrotalus horridus represents the predominant venomousspecies native to the Upper Mississippi River Valley.Documentation of snakebite cases, their clinicalmanifestations and treatment is lacking for this northernMidwest region. Profiling timber rattlesnake bite caseswould provide useful information regarding regionalvenom toxicity and medical management. Consultationwas sought regarding 36 rattlesnake bites, involving 8different rattlesnake species, in the Mississippi RiverValley corridor of southeastern Minnesota, northeasternIowa, and southwestern Wisconsin from 1982-2002.Twenty-seven bites involved timber rattlesnakes. Mostbites occurred in Minnesota (15), followed by Wisconsin(7), and Iowa (5), from April - October. Natural bites(legitimate bites) accounted for 12 cases (44%) and wereinflicted on lower extremities, while 15 (56%) resultedfrom deliberate human manipulation of snakes(illegitimate bites) resulting in bites to the upper body.Average victim age was 33±12 years, and 81% ofvictims were male. All victims were evaluated in amedical facility, 12 were hospitalized. Snakeidentification was confirmed and fang punctures evidentin all cases. Envenomation symptoms were non-existentor minimal in 52% of victims, moderate in 33%, andsevere in 15%, with one fatality. Hospitalized patientsshowed coagulation profile abnormalities withthrombocytopenia (mean platelet count 30 ± 29 x10 3 /mm 3 ) a primary feature. Despite pronouncedthrombocytopenia no bleeding complications occurredin any patient. Antivenom was administered (5-20 vials)in 11 patients (41% of cases), and average hospital staywas 3.5 days. Two patients had fasciotomy, withoutconfirmation of elevated compartment pressures, andagainst toxicology consult recommendation. The causeof death in the one fatality was a result of significantintravenous envenomation, and delayed transport to amedical facility. These clinical experiences with timberrattlesnake envenomations in this geographic regionsuggest that many bites require antivenom therapy,thrombocytopenia without bleeding is a commonsystemic complication, and that rare fatalities occur.34

Kingsbury, Bruce A., Joseph R. Sage, Jennifer V.Manning and John MarshallSpatial Ecology and Conservation of the EasternMassasaugaThe Eastern Massasauga (Sistrurus c. catenatus) is aCandidate for listing as federally Threatened, and isprotected in all of the states and provinces in which itoccurs. Over the last ten years we have been monitoringthe spatial ecology of several populations ofmassasaugas using radio telemetry. We presentconservation insights gained from this work.Massasaugas will find, use, and persist in habitatrefugia. Islands of habitat should be left in constructionareas not only to serve as sources for colonization byplants and animals into restored habitat, but also as safezones for larger animals such as massasaugas thatremain active in the area. Habitat manipulations areoften not unduly deleterious if timed correctly, and mostactivities should be done during the off-season.However, they should also be conducted in a timelymanner, as even low risk actions have more substantialimpacts over time. Gravid females may be attracted toareas of active construction if the manipulated areaprovides a better microclimate for gestation. This meansthat any added mortality from human activity may takea greater toll on the gravid females, potentially affectingthe reproductive output of the population as a whole.Roads may present significant barriers to massasaugas.Paved roads with low traffic rates present almostcomplete barriers, while narrower unpaved roads maynot be as discouraging. Small rivers appear to be readilynavigated. Limitation of areas suitable for hibernation,and the patterns of movement in and out of them, alsopresent significant hazards for massasaugas.Krochmal 1 , Aaron R., and George S. Bakken 2 .1 University of Houston – Downtown, Department ofNatural Sciences, 1 Main Street, Houston, TX 77002.2Department of Ecology and Organismal Biology,Indiana State University, 600 Chestnut Street, TerreHaute, IN 47809.Einstein and Klauber road cruise in heaven: Howunderstanding physics can unlock the secrets ofrattlesnake biologyBiology is an integrative science; therefore, a fullunderstanding of biological phenomena requiresincorporating aspects of disparate scientific disciplines,most notably, physics. Herpetologists typically lack aninterest in physics and therefore tend to omit physicalconsiderations from their scientific reasoning and theirexperimental designs. The absence of physics fromherpetological research is responsible for substantialholes in our understanding of basic reptilian biology andhas led to misconceptions regarding common biologicalphenomena. One example of this failing is our limitedknowledge of the facial pits of pitvipers, thermalradiation receptors that detect fluctuations intemperature. Facial pits were long regarded asspecializations for prey acquisition, but our recent workincorporating principles of environmental biophysicsdemonstrated that pitvipers also use these organs inthermoregulation, indicating that facial pits are generalpurposesense organs with many uses; these mightinclude predator detection and general navigation.Although including physics in our investigationsbroadened our understanding of the facial pits, manymisconceptions persist in the literature, particularlyrelative to the thermal sensitivity, perceptual range andbehavioral utility of these organs. To improve ourunderstanding of facial pit function, we combined theprinciples of thermal physics, radiative heat transfer andmicrometeorology to quantify the thermal signalsemitted by prey, predators and environmental featurestypically encountered by rattlesnakes. We aimed toquantify the perceptual range of the facial pits undernatural conditions and to evaluate the plausibility ofpredator detection as a role of the facial pits. Our resultsdemonstrate that though predator detection via the facialpits might be possible under certain conditions, variationin background surface temperature during the day andearly hours of the night likely impairs the use of thefacial pits to detect prey or predators. These findingsunderscore the notion that embracing physics canadvance our understanding of rattlesnake biology.LaBonte, John P., Department of Ecology, Evolution,& Marine Biology, University of California, SantaBarbara, Santa Barbara, CA 93106-9610Innate prey preference in neonatal Southern PacificRattlesnakes (Crotalus viridis helleri) and changeswith ontogeny.In Santa Barbara County, Crotalus viridis helleriundergoes an ontogenetic shift in prey, feeding primarilyon lizards as neonates and shifting to rodents as adults.Lizard prey may be more suitable for neonates due totheir smaller dimensions and potentially easierdigestibility. Lizards differ morphologically andbehaviorally from rodents therefore the foraging tacticsand sensory cues utilized by neonatal C. v. helleri maydiffer from those used by adults. Since neonatal survivalis dependent on the ability to obtain suitable meals soonafter birth, selection should favor mechanisms thatincrease neonatal foraging success. Neonatal C. v.helleri may therefore be expected to show an innatechemosensory preference for lizards. Using seminaturalisticforaging arenas, I evaluated whether naïveneonatal C. v. helleri have innate preferences for sitescontaining either rodent (Peromyscus maniculatus) orlizard (Sceloporus occidentalis) prey cues. Sinceambush site selection in Crotalus sp. likely depends onprey odor, soiled bedding, placed at opposing corners ofthe arena, and clean bedding as a control served as prey35

cue treatments. Neonates spent significantly more timeand displayed stereotyped ambush behaviors in thelizard treatments. When this experiment was repeatedusing various sized wild caught adults, I found thatpreference was mixed in intermediate size classes (326mm to 600 mm SVL) and strongly favored rodent cuesin snakes over 600 mm SVL. The results indicate thatneonatal C. v. helleri have an innate preference for sitescontaining lizard chemosensory cues and that thispreference shifts to rodents with ontogeny. In nature,prey availability and foraging experience can effect preypreference. Therefore it is unclear if the observedontogenetic shift in preference is a result of innatechanges in chemosensory sensitivity.LaDuc, Travis J. Texas Memorial Museum, TheUniversity of Texas at Austin, 10100 N Burnet Rd, PRC176/R4000, Austin, TX 78758-4445.Fang replacement rates in the western diamondbackrattlesnake, Crotalus atroxAn elaborate maxillary fang replacement system invipers and elapids ensures the presence of a functionalfang on each side of the head in order to deliver venominto would-be prey items. This replacement systemconsists of a series of fangs in various stages ofdevelopment found caudal and dorsal to each functionalfang. Shed fangs are passed through the digestivesystem and can be retrieved from evacuated feces;previous studies recorded between 1 and 12 fangsrecovered from stomach content and evacuated fecalanalyses of rattlesnakes. Little is known about the actualrate of replacement for functional fangs in venomoussnakes, let alone whether the loss is due to cyclicalshedding, feeding activity (predatory strike and/or preyingestion) or both shedding and feeding activities.Estimates of fang replacement rates range from as oftenas once a week to as few as twice a year. This studyattempts to describe normal shedding rates of maxillaryfangs in rattlesnakes and whether this rate is acceleratedwhen the maxillary fangs are used during predatorystrikes. Eight captive adult and sub-adult westerndiamondback rattlesnakes (Crotalus atrox) were fed abiweekly diet consisting solely of euthanized mice forsix months, followed by a diet of only live mice for sixmonths. Each mouse was marked with a small coloredplastic bead to aid in identification of individual feedingevents during analyses of dried evacuated feces; fangsand colored beads were retrieved and counted from driedfeces. Maxillary fang shedding rates will be discussed,in addition to developmental fang anomalies, storage offeces and defecation intervals, and additional bonematerial found in the feces.Lazcano, David, Jr. 1 , Alan Kardon 2 and Robert W.BrysonCentro de Propagación de Especies Ponzoñosas,1 Laboratorio de Herpetología, Facultad de CienciasBiológicas, Universidad Autónoma de Nuevo León, SanNicolás de los Garza, Nuevo León, México, Tel. (81)8332 - 28 89 dvlazcano@hotmail.com; 2 San AntonioZoological Garden, 3903 N. St. Mary's Street, SanAntonio, Texas, 78212, Tel. (210) 734 –7184 ext. 112,reptiles@sazoo-aq.orgReproduction in montane rattlesnakes:Endoherpetology of Crotalus lepidus morulusThe Universidad Autonoma de Nuevo Leon, Facultad deCiencias Biológicas, Laboratorio de Herpetología isholding a small colony of montane rattlesnakes, with acolony of the following species account:Crotalus aquilus: 16 ejemplares, relación ( 4:3:9)Crotalus lepidus klauberi: 17 ejemplares, relación(7:5:7)Crotalus lepidus morulus: 93 ejemplares, relación(21:17:55)Crotalus polystictus: 9 ejemplares, relación ( 2:3:4)Crotalus triseriatus triseiatus: 1 ejemplar, relación(0:1:0)Crotalus willardi silus: 4 ejemplares, relación (2:2)The snakes are from the states of Aguascalientes,Durango, Nuevo Leon, Hidalgo, and Zacatecas. Thepurpose of maintaining this colony in captivity is toobtain optimal physical and biological parameters thatwill help us understand the basic biology of theseMexican species, many of which little is know about,including reproduction, growth, hibernation behavior,thermoregulation, nutrition, and so on. Our goal is toincrease the colony numbers and diversity of species andlocations. As more animals are collected, more data willbe procured. The different mountain chains in Mexico,such as the Sierra Madre Oriental, Occidental, and TrasVolcanic have no doubt contributed enormously to thewide variety of adaptation features; one of which we willwork on is the pattern and coloration found in thesemontane species. Working with these species in the labwill help us understand the adaptation of these differentpatterns and its relationship to other biological aspects.Lee, Yu Man 1 , Lori G. Sargent 2 and Bruce A.Kingsbury 3 . 1 Michigan Natural Features Inventory,Michigan State University Extension, P.O. Box 30444,Lansing, MI 48909-7944, 2 Michigan Department ofNatural Resources, Wildlife Division, Natural HeritageProgram, P.O. Box 30180, Lansing, MI 48909-7680,3Center for Reptile and Amphibian Conservation andManagement, Indiana-Purdue University, Fort Wayne,2101 E. Coliseum Blvd., Fort Wayne, IN 46805.Developing a Conservation Strategy for the EasternMassasauga in MichiganThe eastern massasauga (Sistrurus catenatus catenatus)has declined throughout its range in the U. S. andCanada, primarily due to habitat loss and persecution.36

As a result, the species has been afforded some level ofprotection across its range and, in 1999, was listed as aCandidate for listing as Threatened by the U.S. Fish andWildlife Service (USFWS). Michigan appears to havethe highest number of extant eastern massasaugapopulations. Thus, conservation of the easternmassasauga in Michigan is critical for ensuring thespecies’ long-term viability. Along with other states inthe species’ range, the Michigan Department of NaturalResources is in the process of developing an EasternMassasauga Candidate Conservation Agreement withAssurances (CCAA) with the USFWS. The CCAAoutlines a strategy for conserving massasaugas inMichigan which primarily consists of protecting andmanaging sufficient habitat for multiple, viablepopulations of this snake distributed across the state. TheCCAA currently focuses on viable populations onprotected lands (i.e., publicly-owned lands or landspurposely set aside by non-governmental entities forlong-term preservation). A GIS-based habitat model hasbeen developed to identify potential sites and areas withsuitable massasauga habitat for surveys and inclusion inthe CCAA. Surveys have been conducted from 2001-2004 to assess the species’ current status and distributionin the state and to identify viable populations and areaswith suitable habitat upon which to potentially focus theCCAA. Habitat management guidelines have beendeveloped and are still under review to identify andimplement management practices that strive to minimizeadverse impacts on massasaugas while managing habitatfor this species. The CCAA also recognizes the need foradditional research and education and outreach effortson the eastern massasauga in Michigan. An overview ofthis conservation effort and results to date will bepresented.Kim Lovich 1 , Kent R. Beaman 2 , and Clark R. Mahrdt 3 ;1 Herpetology Department, Zoological Society of SanDiego, PO Box 120551, San Diego, CA 92112-05512 Section of Herpetology, Natural History Museum ofLos Angeles County, 900 Exposition Blvd., LosAngeles, CA 90007; 3 Department of Herpetology, SanDiego Natural History Museum, PO Box 1390, SanDiego, CA 92112A curator and his rattlesnakes: The history ofLaurence Monroe Klauber at the San Diego ZooLaurence Monroe Klauber was an electrical engineer byprofession who, as an amateur herpetologist, madeoriginal contributions to the study of rattlesnakes. Histwo-volume monograph was published in 1956 and stillserves as the definitive work on the genera Crotalus andSistrurus. Klauber served as a consulting curator forboth the San Diego Natural History Museum and the SanDiego Zoo. C.B. “Cy” Perkins, who later becamecurator of reptiles at the zoo, sent Klauber a large seriesof Crotalus viridis from Colorado. This marked thebeginning of a long, productive relationship betweenKlauber and Perkins, which led to the publication of aseven-part series entitled “A Statistical Study of theRattlesnakes” (1936-1940). Klauber’s long history withthe San Diego Zoo later inspired Charles E. Shaw tobecome Perkins’ successor as curator of reptiles inJanuary 1954.Mackessy, Stephen P. Department of BiologicalSciences, University of Northern Colorado, 501 20 th St.,CB 92, Greeley, CO 80639-0017 USAVenom composition in rattlesnakes: trends andbiological significanceVenom glands of rattlesnakes have a largely conservedmorphology, and protein products of the gland are oftenhighly homologous across many species. However,even within a single species (e.g., Crotalus oreganusoreganus and C. o. concolor), very prominentdifferences in absolute composition are observed,suggesting that closely related taxa are utilizing differenttrophic strategies. As with snake venoms generally, aprimary role of rattlesnake venoms is to incapacitateprey remotely and facilitate prey handling. Using SDS-PAGE, two-dimensional electrophoresis, MALDI-TOF,enzyme assays and toxicity studies, we have analyzedand compared venoms of many species of rattlesnakeswith the perspective of placing venom biochemistry intobroader biological contexts. Venom often (but notalways) varies ontogenetically, and this variationcommonly tracks changes in dominant prey type.Venom composition is genetically determined andtherefore is directly related to phylogeny, but withinspecific lineages, venom composition variesconsiderably. Within the constraints of relatedness oftaxa, there is some variability in absolute venomcomposition which appears to be related primarily todiet and secondarily to environment. For example, bothontogenetically and between subspecies/species, highlytoxic venoms generally lack high concentrations ofmetalloproteases, enzymes responsible for much of thestructural damage resulting from envenomation.Conversely, those with potent metalloprotease activitygenerally lack presynaptic neurotoxins characteristic ofthe most toxic venoms, and toxicity versus tissuedamagingeffects of rattlesnake venoms follows apredictable trend. The thrombin-like serine proteasesalso vary ontogenetically, and higher levels in venomsappear to be directed toward mammalian prey. Further,maintenance of venom complexity is likely driven byadaptive detoxification responses of prey, and theensuing arms race has lead to apparent multiplicity ofsimilar activities and upwards of 100 distinct molecularentites in a single venom. Within the rattlesnakes onefinds venom composition strategies which are observedbroadly among venomous colubroid snakes, and thus37

attlesnakes represent an excellent group for studyingvenom evolution in squamates.Malawy, Michael A. School of Life Sciences, ArizonaState University, Tempe, AZ 85287-4501.Thermal biology of Crotalus atroxBody temperature affects animal physiology in manyways, effecting locomotor performance, growth,metabolic rate, and digestion, among others. Identifyingthe selected body temperatures (Tselect) of a seasonallypoikiothermic ectotherm helps in understanding theirecology and behavior. I chose to investigate bodytemperature preferences and variation within a group ofwild Crotalus atrox at a field site located within theupland Sonoran Desert. Snakes were surgicallyimplanted with radio transmitters and miniaturetemperature data loggers (iButtons, made by DallasSemiconductor) to record body temperature during avariety of physiologic conditions and time periods.Experiments were conducted either in the lab using athermal gradient or in the wild in order to investigateenvironmental constraints. Snakes were supplementallyfed to identify any post-prandial variance in Tselectduring each experimental period. Annual thermalprofiles were developed to examine Tselect for bothsexes during their active and inactive seasons andcompared to results obtained from snakes placed in thelaboratory thermogradient. Male and femalerattlesnakes do not appear to differ in Tselect duringeither their active or inactive periods, and they do notappear to show a marked thermophilic response tofeeding. Seasonal temperatures at our field site drivesnake behavior as shown by their seasonal migrationsand daily activity cycles. Snakes were shown to selectbody temperatures within a tight range although,contrary to my predictions, they did not elevate Tselectafter feeding events. Results indicate that C. atrox in theSonoran Desert behaviorally thermoregulate during thewarmest months of the year to stay cooler than themajority of their environment. Snakes tend to selectbrumation sites that afford elevated Tb’s during thecoldest months of the year, although no difference inwinter Tb was detected between the sexes, and nodenning behavior is exhibited at the field site.McGowan, Edwin M. NY-NJ Trail Conference, 156Ramapo Valley Road, Mahwah, NJ 07430.A composite record of mating behavior in freerangingtimber rattlesnakes, Crotalus horridusLong considered poorly suited for testing theory, snakeshave recently attained the status of model organisms forecological research, including studies of reproductivestrategies. Still, most quantitative studies on sexualselection in snake mating systems are based on a fewtemperate species that form predictable matingaggregations. Snake species having a highly dispersedsocial structure during the mating season, such as thatseen in many crotalids, have proven more difficult tostudy quantitatively. For these species, matingobservations have been limited by logistical constraintson continuous monitoring over extended mating seasons,despite advances in radiotelemetry. As a result, fewstudies of free-ranging rattlesnakes have gatheredsufficient observations to examine mating pattern andprocess, and thus, these records often remain unreported.For extensively studied species such as the timberrattlesnake (Crotalus horridus), these observationsconstitute a large, untapped reservoir of information. Inan effort to collate these records and compare my ownC. horridus mating observations (20 pairs) in New York,I solicited unpublished mating data from researcherswho had performed radiotelemetric monitoring of thisspecies. Nine respondents from 7 states providedobservational data on 79 (51M: 28F) individual C.horridus radio-tracked for all or part of the July-September mating season. As some individual snakeswere monitored over consecutive years, the total sampleincluded 110 (72M: 38F) snake mating season records.Heterosexual pairs (n = 43) were reported between July12 and September 28, and peaked during the first twoweeks in August. Fewer than half of the males (24 of 51)paired with at least one female, while 71% (17 of 24) ofnongravid females attracted at least one male. Sixfemales paired with more than one male, consistent withmy observations in New York of within-season multiplepairing and multiple mating by female C. horridus.McMillan 1 , Matthew, and Carl S. Lieb 2 . 1 BiologicalResources Research Center, Las Vegas Field Station,University of Nevada-Reno, Henderson, NV 89015.2 Laboratory for Environmental Biology, CentennialMuseum of Natural and Cultural History, University ofTexas at El Paso, El Paso, TX 79968-0519.Morphological variation in Crotalus basiliscus andCrotalus molossus (Serpentes: Viperidae) with anevaluation of hybridizationThe relationship between Crotalus basiliscus and C.molossus were studied to determine if anymorphological characters would distinguish the taxafrom each other and from potential hybrids. Thetaxonomic validity of C. m. oaxacus was alsoinvestigated. Data for 256 rattlesnakes were analyzedusing 38 meristic and two morphometric characters fromthe ranges of both species. Discriminant function andprincipal components analyses were used to compare themorphological variation in the two species. Resultsindicate that C. basiliscus and C. molossus significantlydiffer in the number of ventrals, subcaudals, and headscales. Four possible hybrid zones were identifiedbetween the two species. Hybridization in those regionsmay be possible, but isolating mechanisms are likely tobe present. Data also suggests that C. molossus38

nigrescens is not a valid subspecies but that C. m.oaxacus is recognizable. The taxonomic status of C. m.estebanensis, however, is unresolved.Meik, Jesse M. Department of Biology, The Universityof Texas at Arlington, Arlington, TX 76019-0498.Morphological analysis of the contact zone betweenthe rattlesnakes Crotalus mitchellii stephensi andCrotalus mitchellii pyrrhusI examined patterns of morphological variation from theputative contact zone between two subspecies of thespeckled rattlesnake (Crotalus mitchellii stephensi andCrotalus mitchellii pyrrhus). Various analyses using adata matrix of 30 external anatomical charactersdemonstrated that morphological discontinuity ratherthan clinal variation best describes the pattern ofgeographic variation from the contact zone. This findingcontradicts the prevailing opinion stated by previousworkers that these two subspecies are united byintergradation. Although linking cause with pattern isnotoriously difficult in studies of geographic variation,the abrupt phenotypic change observed between C. m.stephensi and C. m. pyrrhus coupled withbiogeographical considerations suggests that the taxonstephensi, which is isolated from all other subspecies ofC. mitchellii other than pyrrhus, may represent a distinctevolutionary lineage.Mociño Deloya, Estrella 1 , Kirk Setser 2 , and DavidLazcano Villarreal 3 . 1 Museo de Zoología de la Facultadde Ciencias, Universidad Nacional Autónoma deMéxico, Ciudad Universitaria, A.P. 70-399, D.F. C.P.04510, México, 2 Department of Biological Sciences,University of Notre Dame, Notre Dame, IN 46556,USA,3 Laboratorio de Herpetología, UniversidadAutónoma de Nuevo León, A.P. 513, San Nicolás de losGarza, Nuevo León C.P. 66450, México.Cannibalism of non-viable offspring by postparturient female Crotalus polystictusAs part of a long-term, mark-recapture study of Crotaluspolystictus, we collected gravid female snakes duringJune-July 2004 and maintained these snakes in captivityto parturition. Seventeen females gave birth to littersincluding one or more non-viable neonates. Toinvestigate female cannibalism of non-viable offspring,we left non-viable neonates as well as all live siblingstogether with females for 10-50 hours post parturition.Ten females consumed all or some non-viable offspring.No female consumed a live neonate. Females thatconsumed offspring gave birth to greater masses ofnon-viable offspring (15.3 g, N = 7), than did femaleswhich did not consume offspring (5.3 g, N = 7).Females consumed a mean 13.5 g (N = 8), representing13.4 % of postpartum mass. Females consumed bothstillborn neonates and undeveloped ova. Consumptionof non-viable offspring confers energetic benefits tofemales, and survival benefits to both females and livesiblings. Females gain an immediate meal at a timewhen many are starved or in poor condition. Bothfemales and siblings may experience improved survivaldue the removal from the birth site of chemical cuesreleased by rotting ova and dead neonates.Moon, Brad R., Department of Biology, University ofLouisiana at Lafayette, Lafayette LA 70504From physiology to fitness: The cost of self defense inrattlesnakesDefensive behaviors in animals are often energeticallyexpensive. The cost of these behaviors may affect otheraspects of an animal’s biology, such as feeding andreproduction. However, because of their irregular andperhaps infrequent use, the potential ecological andreproductive costs of defensive behaviors are difficult tostudy. The shaker muscles of rattlesnakes are anexcellent system for studying the potential costs of aspecialized defensive system. Shaker musclecontractions during rattling are among the fastest andmost energetically-expensive contractions in vertebrates.Therefore, the high cost of rattling may increase feedingrequirements or use energy that could otherwise beavailable for reproduction. I used energetic modelingbased on published field and laboratory data to testwhether the annual cost of rattling in western diamondbackedrattlesnakes (Crotalus atrox) can be high enoughto increase feeding demands or decrease femalereproductive output, which is a key component offitness. The metabolic data alone for rattlesnake shakermuscles suggest that rattling is a very costly defensivebehavior. However, when the metabolic rate duringrattling is incorporated into energetic models along withthe frequency and duration of rattling bouts, the resultsindicate that under most circumstances rattling has smalleffects on the annual energy budget, feeding ecology,reproduction, and fitness. Only very frequent andprolonged rattling by relatively small individuals, whichproduce small broods of offspring, is likely to increasefeeding needs or reduce fecundity. Rattling presumablyenhances rattlesnake survival by deterring potentiallydangerous animals; this enhanced survival probablycomes at a low cost.Müller, Paul – Department of Biogeography,Bioanalytic and Toxicology, University of Trier, FB VI,54286 Trier, Germany.Evolution and biogeography of the Crotalus durissusComplex in South AmericaThe Crotalus durissus “complex” embodies some of themost interesting biogeographical and phylogeneticalproblems in the Neotropical realm. Crotalus durissus isdiscontinuously distributed in open landscapes fromnorthern Columbia to Argentina and is present in theislands of Aruba (C. unicolor), Margarita, Los Testigos,39

Marajo, and some isolated Savanna Islands in theAmazon and the Guayanas. C. durissus preferssavannas, caatings and cerrados but in some areas (f. e.Maraca Rainforest Project in Roraima; cf. MILLIKENAND RATTER 1998) “several large adults were observedup to 0,5 km into the forest…”. Size and color of thedifferent population have strong relationships with thelandscape type and the food resources. Clinal variationfrom south to north, elimination of the variability inisland population, molecular datas indicate that C.durissus is a semi species in the Super species-complexwith C. simus, C. totonacus and C. basiliscus). Betweencumanensis- and vegrandis-populations we found ahybrid belt in the Orinoco-area. For molecular data it’simportant to know the exact place of origin. C.pifanorum in the Orinoco area west from C. vegrandis isan integrate between C. d. cumanensis and C. vegrandis.The unicolor-population is longer isolated from themainland population as some molecular data suggests.That is not the case by C. durissus-populations from IslaMargarita. C. d. marajoensis have the closestrelationship to C. durissus-populations from Amapa, C.d. ruruima to C. d. cumanensis. C. vegrandis have alonger separation from C. durissus than C. totanacusfrom C. simus. C. d. maricelae is a mountain populationof C. d. cumanensis. The distribution and evolution ofthe C. durissus-populations in South America are aresult of climatic and vegetation fluctuation in theWisconsin and Postglacial time. During the Wisconsinglaciation and in the Postglacial Time lager openlandscapes exist in the area where C. durissuspopulationsstill exist today.Murphy, Robert W., 1 Robert W. Bryson, Jr. 2 , AmyLathrop 1 , David Lazcano 3 , and Fernando Mendoza-Quijiano 4 . 1 Centre for Biodiversity and ConservationBiology, Royal Ontario Museum, 100 Queen’s Park,Toronto, Ontario M5S 2C6 Canada, 2 113 Walnut St.#97, Neptune, New Jersey 07753, 3 Laboratorio deHerpetología, Universidad Autónoma de Nuevo León,Apdo. Post. 513, C.P. 66450, San Nicolas de los Garza,Nuevo León, México,4 Instituto TecnológicoAgropecuario de Hidalgo, Km. 5.5 Carr. Huejutla-Chalahuiyapa, Apdo. Post. 94, C.P. 43000, Huejutla deReyes, Hidalgo, México.The evolution and biogeography of the Crotalustriseriatus species groupWe investigated the relationships among the highmontane, small-bodied rattlesnakes formerly referred toas the triseriatus species group of Crotalus. Nucleotidesequence data were gathered from multiplemitochondrial genes. For most samples, DNAacquisition involved non-destructive sampling. Shedskins from field-caught individuals accounted for mostof the individuals (>90) used in our study. The alignedsequence data were evaluated using maximumparsimony methods. Our preliminary evaluationrevealed the presence of both monophyletic and nonmonophyleticlineages among the rattlesnakes. Ingeneral, the branching sequence conformed to that of anearlier study of the phylogenetic relationships amongrattlesnakes.Nisani, Zia 1 , William K. Hayes 1 , Joseph F. Banashek 2 ,and Joseph P. Banashek 2 1 Department of NaturalSciences, Loma Linda University, Loma Linda, CA92350 USA, 2 P.O. Box 235, Adelanto, CA 92301 USAFactors associated with nocturnal activity in thewestern Mojave Desert: Rattlesnakes versusnonvenomous snakesApart from temperature, few studies address theenvironmental factors that influence activity levels ofsnakes. The purpose of this study was to compare thatenvironmental factors that influence nocturnal activitiesof rattlesnakes and non-venomous (colubrid) snakes ata western Mojave Desert study site. Snake encountersduring road-hunting via automobile were analyzed for249 nights (time frame) during the active seasons of2002-2004. Nightly surveys were conducted along astretch of dirt (primarily) and paved roads 7 mi west ofAdelanto, California. Analyses of covariance(ANCOVAs) revealed that rattlesnake activity increasedwith greater moonlight, higher temperatures, and higherhumidity. Rattlesnake activity also varied significantlybetween months and years. Nonvenomous snakeactivity varied only between years (with an interactionbetween years and months). Other factors were notsignificant for either group, including lunar phase,barometric pressure, wind speed, and wind direction.All of the significant effects were very weak, explainingless than 11% of the variance in encounter rates.Nowak, E.M. USGS Biological Resources Division,Southwest Biological Science Center, Colorado PlateauResearch Station, Box 5614, Northern ArizonaUniversity, Flagstaff, AZ 86011, USANuisance rattlesnake movements and ecology inArizona (USA) national parksTranslocation of so-called “nuisance” rattlesnakes frompublic and residential areas to undeveloped habitats is anincreasingly controversial management practice in thesouthwestern United States, and is often ineffective, inaddition to causing increased mortality in translocatedanimals. In 2002 I re-initiated telemetry studies ofwestern diamond-backed rattlesnakes (C. atrox) at Tontoand Montezuma Castle National Monuments in Arizona,to begin to understand the proximate causes of nuisancerattlesnake behavior and movements. I also conductedsmall mammal trapping to compare potential prey basepopulations near and away from human-modifiedhabitats at the monument, and analyzed microhabitatsused by snakes in different areas. Movement and prey40

ase data will be presented in conjunction with previoustelemetry studies of C. atrox movements at TuzigootNational Monument. I will discuss summer and winteruse of human-modified habitats by rattlesnakes,movement patterns and range size, detection rates,behavior when detected, and results of potential preysampling. In my conclusions, I will discuss the scientificimplications of this research for the management ofrattlesnakes on publicly- managed lands with developedareas (visitor, picnic, and/or staff housing facilities).Owens, Thomas C. Department of Herpetology, SanDiego Zoo, P.O. Box 120551, San Diego, CA 92112.Fire Ecology of a Southern California Rattlesnake: acase of survivalLate summers in southern California are peak season forwild fires. In San Diego County, much like the rest ofsouthern California, the influence of periodic burning isespecially important in the Chaparral ecosystem. Firesoccurring naturally maintain the stable nature of thehabitat. As humans have moved into these habitats theyhave unnaturally altered the frequency and intensity ofthese wild fires. Both natural fires and those caused byhumans are certain to effect the amphibian and reptilepopulations. Fossorial lizards and snakes have highsurvival rates during fire events. In November of 2003,the Cedar fire struck San Diego County. In July of2004, a Southwestern Speckled Rattlesnake Crotalusmitchelli pyrrhus was found at the El Capitan Reservoirin the Blossom Valley area of San Diego County whichis located within the Cedar fire burn area. The C. m.pyrrhus was found with burn scarring both caudally andon its head. The location of the burns creates aninteresting hypothesis for how the rattlesnake was ableto survive the intense and fast moving fire. A thoroughstudy of this species of rattlesnake and its fire-relatedecology would aid in the further development of aconservation strategy.Owings, Donald H. and Richard G. Coss, Departmentof Psychology, One Shields Ave., University ofCalifornia, Davis, CA 95616-8686Hunting ground squirrels: Constraints andopportunities for rattlesnakesOur program of research on the predator-preyrelationship between rattlesnakes and ground squirrelshas emphasized the ground squirrel side of that system.But, we will discuss how some of the antipredatoradaptations of ground squirrels have both constrainedand generated opportunities for the predatory behaviorof rattlesnakes. For example, ground squirrelpopulations undergoing sustained predation fromrattlesnakes have evolved the capacity to neutralize theirvenom. This has constrained rattlesnake predatoryoptions in several ways. Rattlesnakes (1) can only killsquirrel pups, (2) face the danger of antipredatoraggression from resistant and protective adults, and (3)can only hunt squirrels during the short season beforepups outgrow their vulnerability. But, the adaptations ofsquirrels to rattlesnake predation has also produced someopportunities for the snakes. (1) The very reliablydevelopingbehavioral antisnake system is expressedprecociously in pups, sometimes leading them toconfront rattlesnakes and so become easy prey. (2)Squirrel populations lose their venom resistance quicklyunder relaxed selection from rattlesnakes, but retain andeven intensify their system for aggressive confrontationof snakes. On recontact with rattlesnakes, e.g., at themargins of the rattlesnakes’ geographic range, thesquirrels’ antipredator aggressiveness can increase theirvulnerability to predation in the absence of protection byvenom resistance. Additional topics will include theopportunities and limits imposed by mutual assessmentbetween squirrel and rattlesnake during encounters, andthe implications of the squirrels’ adaptation to thetemporal properties of threat posed by the ambushhuntingmethods of rattlesnakes.Parker, M. Rockwell 1 . 1 Department of Zoology,Oregon State University, 3029 Cordley Hall, Corvallis,OR, 97331.Airborne cues and their role in rattlesnake predatorybehaviorResearchers have investigated the importance ofsubstrate cues in rattlesnake chemical ecology for thebetter part of the past century. We know that manyspecies of rattlesnakes, if not all, engage in the modalaction pattern of strike-induced chemosensory searching(SICS). Substrate cues play a central role in providingrattlesnakes with the information necessary forsuccessful prey relocation during SICS, but theselaboratory studies have neither displayed nor discountedthe importance of alternate sources of chemicalinformation in the post-strike environment. Similarly,research on rattlesnake pre-strike behavior has taken onthe same substrate cue focus. Over the past three years,I have found that rattlesnakes show distinct behavioralpatterns in response to airborne cues in both the pre- andpost-strike contexts when such cues are presented to thesnakes in a Plexiglas Y-maze. Rattlesnakes (Crotalusviridis oreganus) can use only airborne informationduring the relocation process, but the snakes display adistinct preference for substrate cues post-strike. Prestrike,rattlesnakes do not show overt reactions toairborne cues like they do to substrate cues, but bothairborne cues and unscented airflow can elicit an active,pre-strike prey searching behavior pattern that isindistinguishable from post-strike airborne trailing.Lastly, rattlesnakes are capable of detecting andsuccessfully following air-deposited (rather than mousedeposited)chemical trails post-strike, suggesting thatairborne trailing plays a functional role in the chemical41

ecology of these snakes due to the plasticity of thesecues. Though airborne cues appear to encode either adifferent amount or a different type of information thansubstrate cues, I have shown that airborne cues likelyserve as an alternative source of useful, prey-derivedchemicals for rattlesnakes both pre- and post-strike.Parsons 1 , Harry and Mike Sarell 2 . 1 Bufo Incorporated,Box 91332, West Vancouver, BC, V&V 3N92 Ophiuchus Consulting, 34017 97 th St., Oliver, BC, V0H1T0.Managing a landscape with rattlesnakesThe Osoyoos Indian Band Development Corporation(OIBDC) is developing a substantial portion of its over12,000 ha in the south Okanagan Valley of B.C. toprovide economic benefits to its members. In addition toits agricultural, recreational and tourism developments,the OIBDC has established large conservation areas, anda desert and heritage interpretive centre to ensure thatvisitors and workers are aware of the natural and culturalsignificance of this restricted and endangered ecosystem.The area is also important habitat for the recentlyreclassified northern pacific rattlesnake (Crotalusoreganus). This species has a very restricted range inCanada and is a species of concern. The Nk’Mip Desert& Heritage Centre is developing a safety andmanagement plan for this species for an approximately250 hectares area, about a quarter of which is underdevelopment. The words “safety” and “management”refer both to rattlesnakes and people reflecting theBand’s desire to protect visitors, agricultural workers,Centre staff, and rattlesnakes. In an approximately 14-month period spread over three years, since themanagement study began, researchers have captured,collected data from, and uniquely marked 304 snakeswith PIT tags; recaptured 51 of these at least once; andused radio-telemetry to monitor the movements of 23rattlesnakes. During the same period, the authors areaware of 21 rattlesnake mortalities and one human biteIn the study area. Many of the captured snakes werereported by the public as a result of the centre’spromotion of its management work to visitors includingexhibits and daily talks focusing on rattlesnakes.Rattlesnakes have charisma, and the centre’s publiceducation has attracted significant interest in the projectfrom media, visitors and the local community. Otherinitiatives include rattlesnake safety training for allworkers in the area, snake fencing, and promoting thisspecies as a component of the area worthy of pride andprotection. The challenge for management is to balancethe traditional issues of safety for people and snakes,benefits and risks of species relocations and othermanagement techniques, and the rattlesnake’sunexpected move towards becoming the focus of anemerging ecotourism market.Patten, Tracy J. 1 , Daniel D. Fogell 2 , and James D.Fawcett 1 . 1 Department of Biology, University ofNebraska at Omaha, 6001 Dodge St., Omaha, NE68182, 2 Southeast Community College, 8800 ‘O’ St.,Lincoln, NE 68520-1299.Conservation of the Massasauga (Sistrurus catenatus)in Southeast Nebraska.The Massasauga (Sistrurus catenatus) is classified as athreatened species in Nebraska. It survives in only a fewseverely fragmented populations where mesic to hydrictallgrass prairie communities still remain relativelyunaltered. In March 2004 an ecological study waslaunched to investigate the conservation needs of theMassasauga (Sistrurus catenatus) in Nebraska. Markrecapturetechniques were employed to estimatepopulation size, define population structure, and monitorseasonal growth. Additionally, seasonal activity, spatialecology, and habitat use were investigated usingradiotelemetry at two state-controlled wildlifemanagement areas. As of October 2004, elevenmassasaugas were still being radiotracked and spatialdata have not yet been analyzed, however sufficientdemographic data have been collected to present apreliminary description of the population structure.Mean SVL for all snakes except neonates and young-ofyearwas 528.0 mm ± 15.4 SE (N=47). There was nosignificant difference in SVL between males andfemales. The sex ratio was 1.6:1 (N=47), which isslightly in favor of males, however the sex ratio for allsnakes with either a single rattle segment or a button was0.94:1 (N=31) and is much closer to unity. Massasaugasuse crayfish burrows for hibernation in Nebraska, andemergence was observed as early as 25 March.Reproductive behavior was observed immediately postemergenceduring early spring as well as during midsummerand early fall. Gravid females experienceparturition in August, and the mean litter size observedwas 7.6 (N=3). Mean SVL for neonate and young-ofyearmassasaugas (single rattle segment or button only)was 232.2 ± 6.0 SE (N=31). Results presented here arepreliminary. Data acquisition is still ongoing and willcontinue throughout the 2005 season.Pérez, John C 1 ., Robert W. Finberg 2 and Elda E.Sánchez 1 . 1 Natural Toxins Research Center, TexasA&M University-Kingsville, 920 University Blvd.,Kingsville, TX 78363, 2 Department of Medicine,University of Massachusetts Medical School, Worcester,MA 01605Important Considerations in Developing AntivenomThe venom delivery system of venomous snakes hasevolved to insure efficient capturing of prey. Venomoussnakes with a single injection release venom into itsvictim that has immediate effect. The immediate actionof the venom can create a medical emergency whenhumans are the victims. Current approaches to treatment42

of victims of snakebites rely on rapid injection ofantiserum or purified antibodies from antiserum toneutralize the effects of the toxins. The best and mostacceptable form of treatment is with antivenomconsisting of purified IgG, or its fragments F(ab’) 2 orFab. There are numerous antivenoms manufacturedthroughout the world and each is produced in a differentway. The intent is to review areas of research that needto be further developed for the production of moreeffective antivenoms. One of the focal points is todiscuss the clearance of venom from circulation byerythrocytes, which seems to be missing in the literaturepertaining to the treatment of envenomation. Theinformation presented will also touch upon theinadequacies of antivenom testing, reasons why the Fcregion of the IgG should not be removed and theimportance of new animal models for testing andproducing antivenoms.Place, Aaron J. and Charles I. Abramson. Laboratory ofComparative Psychology and Behavioral Biology,Oklahoma State University, 215 N. Murray, Stillwater,OK 74078.Learning in snakes, II: Empirical studies of learningin rattlesnakesHabituation is defined as a decrease in response to aregularly repeating stimulus. This type of nonassociativelearning is ubiquitous throughout the animalkingdom and is adaptive in several ways. We performedexperiments to determine if several components ofrattling behavior exhibited habituation. Ten westerndiamondback rattlesnakes (Crotalus atrox) werecollected and induced to rattle using an apparatus inwhich stimuli were presented automatically. Thedependent variables included the presence of rattling,latency of rattling, and duration of rattling. Audiorecordings were also made. Each snake was induced torattle every five minutes until it failed to rattle in 10consecutive trials or until it reached a maximum of 120trials. If the ten trial criterion was met, a dishabituatingstimulus was presented to rule out sensory adaptationand effector fatigue. The entire procedure was repeatedfor four consecutive days with each animal. Individualdifferences in habituation rate were observed.Additionally, rattling latency and duration also showeda decreasing curve over time, indicatative of habituation.However, the rates of decrease differed among thesebehavioral components and between individuals.Spontaneous recovery was apparent in most, but not allsnakes. Some individuals also showed retention ofhabituation of response over days. Preliminary resultsof signaled avoidance training and an operant procedureusing rattlesnakes are also discussed. These results areplaced in the context of behavioral ecology and theirimplications for studies regarding the origin of the rattle.Possardt, Earl E. 1 , W.H. Martin 2 , W.S. Brown 3 and J.Sealy 4 . 1 U.S. Fish & Wildlife Service, Dept. of Biology,University of West Georgia, Carrollton, GA 30118, 2Rt. 3, Box 804, Harpers Ferry, WVA 25425, 3 Dept. ofBiology, Skidmore College, Saratoga Springs, NY12866, 4 313 Tyler Lane, Boone, NC 28607A range wide action plan for the timber rattlesnake(Crotalus horridus): hope for actual conservationprogress or more paper?A range wide conservation plan is under development byan alliance of state, federal, university, NGOs, andprivate individuals with extensive field experience andknowledge of timber rattlesnake biology, ecology andpopulation status in particular states or regions. Thisplan reviews population status, legal protection, threats,and conservation needs at the state level as well asidentifies conservation action priorities at the regionaland range wide level. The historic occurrence ofCrotalus horridus is documented in 33 states andOntario, Canada, with possible historic occurrence intwo additional states based on unverifiable reports. It isnow extirpated from Canada and two states, and severelyto significantly reduced in 20 states. A variety of factors,such as winter denning requirements in much of itsrange, long age to sexual maturity, low birthingintervals, and small litter size, make Crotalus horridusvulnerable to a plethora of threats elucidated in the plan.Increasing threats, inadequate range wide legalprotection, and extreme vulnerability due to life historyfactors will result in further extirpation of Crotalushorridus populations and significant reductions of itsrange without concerted conservation intervention.Multifaceted efforts described in the conservation planprovide a basis for local as well as range wide actionthat can reduce the overall range wide decline, maintainhealthy populations, and allow for the recovery ofdepleted populations. This paper summarizes the majorfindings and recommendations of the conservation plan,as well as the process and expectations of its utility forreal conservation progress in the future.Prival, Dave. School of Natural Resources, Universityof Arizona, Tucson, AZ 85721.It’s Not Easy Being Green: Selected Natural HistoryAspects and A New Hypothesis Regarding theEvolution of Sexual Dichromatism in Crotalus lepidusklauberi.Adult Crotalus lepidus klauberi differ from most snakesin that they can be readily identified as male or femalebased on their dorsal coloration in at least somepopulations. Males are green, whereas females are gray.We captured, measured, and marked 105 Crotaluslepidus klauberi (not including recaptures) in Arizona’sChiricahua Mountains in 1999 to learn more about thenatural history of this subspecies. We captured gravidfemales between 16 July and 16 August; mean number43

of embryos detected per gravid female was 3.7. We firstfound neonate snakes in early August, and maternalattendance of young is likely. Most gravid females werefound on south- and west-facing slopes, whereas mostnon-gravid females and males were found on northerlyslopes. Gravid female locations were warmer relative toair temperature, had more grass cover, and had lesscanopy cover than non-gravid female and malelocations. This microhabitat difference could explainthe sexual dichromatism of C. l. klauberi, as the greencolor of males may enhance crypsis on the cooler, wetterslopes inhabited by males and non-gravid females, butmay increase risk of predation on the warmer, drierslopes inhabited by gravid females.Rabatsky, Ali M. Department of Biology, University ofLouisiana (Lafayette), 300 E. St. Mary Blvd., Lafayette,LA 70504.Rattle loss in insular rattlesnake speciesSeveral hypotheses have been suggested and tested in anattempt to explain the evolution of the rattle. Becauseall extant species of rattlesnakes only rattle in defensivecontexts, the most widely accepted function of the rattle,both historically and presently, is that it functionsaposematically to alert or warn potential predators. It iswell-known in the literature that relaxed selection frommammalian predators may be associated with rattle lossin insular species. Thus, islands that lack mammalianpredators offer a unique opportunity to study changes inthe rattling system. Because the rattle is a complexfeature, its evolution involved a number of changes inrattlesnake behavior, morphology, and physiology. Itfollows then that rattle loss might also involve changesin these same components. These changes may reflectreduced predation pressures and/or altered foragingregimes, and may provide new evidence for howcomponents of integrated and specialized systemsbecome decoupled during vestigialization. To test theseinferences, I collected data on the behavior, morphologyand rattling performance of C. catalinensis and C.lorenzoensis, two endemic insular rattlesnake speciesknown to be experiencing rattle loss. I compared thesedata to those collected from their closest relative, C.ruber, as well as to C. atrox. Preliminary analysisrevealed that certain components of the rattling systemare being lost more rapidly than others, but the pattern ofloss is similar for both insular species.Rabatsky, Ali M. Department of Biology, University ofLouisiana (Lafayette), 300 E. St. Mary Blvd., Lafayette,LA 70504.Caudal luring as a precursor in rattle evolution: Atest using an ancestral rattlesnake, Sistrurus miliariusbarbouriBecause of its prevalence among pitvipers, caudal luringhas been suggested to be a synapomorphy within thisgroup and perhaps the behavioral and morphologicalprecursor to rattling in rattlesnakes. However, fewempirical studies have examined the phylogeneticdistribution of caudal luring or the role that caudal luringand rattle segmentation may have played in theevolution of the rattle. In addition to phylogeneticcharacter reconstruction, I made behavioral observationsusing the ancestral rattlesnake Sistrurus miliarius to testthe hypothesis that the rattle may have evolved from acaudal lure. Phylogenetic analysis showed that caudalluring and its associated tail color are plesiomorphicamong the viperids and are widespread amongambush-foraging squamate taxa. In experimental trials,pygmy rattlesnakes used caudal luring to attract prey,but rattle segmentation did not affect luring success.While it is possible that caudal luring could have beenthe precursor to rattling given phylogeneticreconstruction, experimental results do not support thehypothesis that the segmented rattle derived from acaudal lure. Alternative hypotheses for the evolution ofthe rattle are discussed.Reinert, Howard K. 1 , Lauretta M. Bushar 2 , and R.Andrew Odum 3 . 1 Department of Biology, The College ofNew Jersey, P. O. Box 7718, Ewing, NJ 08628-0718,2 Department of Biology, Arcadia University, 450 S.Easton Road, Glenside, PA 19038, 3 Department ofHerpetology, Toledo Zoological Society, P. O. Box140130, Toledo, OH 43614-0801.The ecology and conservation biology of the ArubaIsland Rattlesnake, Crotalus unicolor.Crotalus unicolor is considered to be one of the rarestknown rattlesnakes. The total geographic distribution ofthis species is restricted to approximately 76 km 2 on the175 km 2 island of Aruba. Between 1993 and 2004 a totalof 185 specimens of C. unicolor were captured, PITtagged and released. During this time period 57 of thesespecimens were monitored with radiotelelemetry forperiods of up to 3 years. These efforts resulted in 3,656telemetrically-assisted observations of the ecology andbehavior of free-ranging C. unicolor. The results of thisextensive field study document the current status andecological requirements of this species, includingquantitative descriptions of spatial biology and habitatpreferences. Our multifaceted conservation managementprogram for this endangered species has focused uponprotecting nearly half of the remaining habitat throughthe establishment of the 35 km 2 Arikok National Park,education of government officials, Park personnel andthe general public, development of a program for dealingwith nuisance snakes, control of a potentiallycompetitive invasive species (Boa constrictor), andcontinued research involving habitat improvement andrestoration.44

Reinert, Howard K., Department of Biology, TheCollege of New Jersey, P. O. Box 7718, Ewing, NJ08628-0718.A telemetric study of the survivorship, behavior, andspatial ecology of neonatal Timber Rattlesnakes,Crotalus horridus.Between 1981 and 1994 16 neonatal TimberRattlesnakes (Crotalus horridus) were monitored withradiotelemetry from birth to a maximum of 100 dayspost-parturition. This sample included siblings from 4separate litters. All litters were born at distances ofbetween 20 m and 400 m from their mother’shibernaculum. Dispersal from the parturition site did notoccur until after the first molt. The ensuing movementsof the neonates were highly variable, even amongsiblings from the same litter. However, correlatedmovements among siblings were frequent and directedmovements to known hibernacula were demonstrated by9 snakes. Neonates moved distances of up to 1.7 kmfrom their parturition site. The signal from only onesnake was lost prior to hibernation. It is unkown whetherthis loss was due to predation or pre-mature transmitterfailure. Even if predation were responsible for the loss ofthis signal, the maximum mortality rate for the periodfrom birth to hibernation ingress for these 16 snakeswould be only 6.25%, a rate much lower than expectedfor neonatal rattlesnakes. Of the remaining 15 snakes, 3hibernated at the maternal hibernaculum, 6 enteredhibernacula known to be occupied by other adultrattlesnakes from the population, and 6 hibernated atsites not known to be active hibernacula. Overwinteringsurvivorship could not be determined for this sample ofsnakes due to transmitter failure prior to egress.Rowe, Matthew P. and John B. Sealy. Department ofBiology, Appalachian State University, Boone, NC28608Hibernaculum or bust: species preferences in thescent-trailing behavior of neonatal timberrattlesnakes (Crotalus horridus)Timber rattlesnakes (Crotalus horridus) in northerntemperateregions survive severe winters by seekingrefuge in communal, mixed-species hibernacula.Gestation and parturition occur some distance from thepopulation's hibernaculum, requiring fall migration to anovel location by the newborn snakes. The mechanismby which newborn rattlesnakes locate these novel siteshas not been thoroughly investigated. Studies havesuggested that scent trails laid down by conspecificsmay guide young to the hibernaculum. In this study, weexamined the ability of newborn timber rattlesnakes totrack the scent trails of conspecific adults, includingtheir mothers, and other snake species sympatric withtimber rattlesnakes. Six scent treatments consisting ofthe newborns' mother, an unrelated C. horridus,Agkistrodon contortrix (copperheads), Elaphe obsoleta(black rat snakes), Nerodia sipedon (northern watersnakes), and a "no scent" control were utilized. Wetested trailing preferences across an open arena with sixnewborns each from four different populations (n=24).Scent treatments were presented along one of two 14-cmwide, 100-cm long pathways angled 52 degrees left andright of the snake's point of entrance to the 120 X 180 X60 cm arena. Treatments were systematically counterbalancedacross all trials. Results demonstrated thatwhile neonatal timber rattlesnakes may recognizesympatric heterospecifics, they only trail conspecificswith no statistical preference for their mothers. Ourresults suggest that “head-starting” and repatriation ofjuvenile timber rattlesnakes into areas where C. horridushas been extirpated may be difficult.Rundus, Aaron R. 1 and Donald H. Owings 2 . 1 AnimalBehavior Graduate Group, University of CaliforniaDavis, One Shields Ave., Davis, CA 95616,2 Department of Psychology, University of CaliforniaDavis, One Shields Ave., Davis, CA 95616.Infrared communication: The use of a snakedirectedinfrared signal by California groundsquirrels (Spermophilus beecheyi) during predatoryencounters with northern Pacific rattlesnakes(Crotalus viridis oreganus).How do we account for the astonishing diversity in theforms of animal signals? Answers to this long-standingquestion in biology have typically focused on both thevariety of messages that animals must encode in signalsand the multiplicity of media through which signalsmust travel. However, animal signals must also workthrough the sensory systems of signal targets and as aconsequence, sensory specializations of target animalsare additional important sources of selection on signalstructure. Here we report evidence that the infraredsensory system of northern Pacific rattlesnakes hasshaped the tail-flagging signal used by California groundsquirrels, while harassing these predators. We found thatthese squirrels differentiated infrared-sensitiverattlesnakes from infrared-insensitive gopher snakes,Pituophis melanoleucus, adding an infrared componentto tail flagging only during encounters with rattlesnakes.To the authors’ knowledge this is the first known case ofan animal signal that utilizes infrared radiation.Combining elevated infrared emission with tail flagginglikely serves to increase the efficacy of this harassmentsignal to rattlesnakes, effectively deterring these ambushpredators from remaining in the vicinity of squirrel pups.In order to test this hypothesis we created bio-roboticsquirrel models capable of interacting with rattlesnakesduring simulated predatory encounters. These highlyrealistic (taxidermed) robots capable of heating totypical ground squirrel head and body temperatures alsohave independently regulated heating systems in theirtails allowing for tail infrared emission levels to be45

experimentally manipulated in a tightly controlledmanner. The robo-squirrels mimicked ground squirreltail flagging behavior, automatically adjusting the rateand number of cycles of tail flagging as a function of thedistance of the rattlesnake to the robot. Rattlesnakesubjects each received a series of four experimentaltrials with robo-squirrels that were configured to emitfour different levels of infrared radiation. Preliminaryresult from these simulated predatory encounters will bepresented here.Sahin-Tóth, Miklós 1 and Takacs, Zoltan 2 . 1 Departmentof Molecular and Cell Biology, Boston UniversityGoldman School of Dental Medicine, Boston, MA02118; 2 Department of Pharmacology, Yale UniversitySchool of Medicine, New Haven, CT 06520Surviving between infrequent meals: enhancedstabilization of rattlesnake (Crotalus) trypsinogens.Trypsinogen, highly conserved among all vertebrates, isthe primary digestive pro-enzyme responsible for thebreakdown of proteins in the ingested food. Whilestored inside the pancreas trypsinogen could catalyze itsown activation (autoactivation), a potentially lethalprocess that is repressed by the trypsinogen activationpeptide, a 7-10 amino-acid long segment upstream fromthe mature trypsin sequence. In most vertebrates,trypsinogens are stored in the pancreas for relativelyshort periods of time ) hours to days ) as the frequentingestion of meals demands a matching enzyme releaseand activation. In contrast, the feeding interval ofsnakes could extend up to weeks or months. Thisextreme feeding habit places a special burden on thesnake digestive physiology, including the effectiveinhibition of intra-pancreatic autoactivation oftrypsinogen during the interdigestive periods.Consequently, we argue that in snakes specialbiochemical mechanisms have evolved to preventtrypsinogen autoactivation and this trait fulfils aphysiological prerequisite for infrequent feeding. Totest this hypothesis, we have cloned the cDNA of 6distinct trypsinogen isoforms from the pancreas of theWestern diamondback rattlesnake (Crotalus atrox).Sequence analysis revealed that all Crotalustrypsinogens have unique activation peptides in whichthe tetra-Asp motif typical of most vertebrates isextended by one or two extra Glu or Asp acidic aminoacids.Next, to establish the biochemical significance ofthese unique sequences, we expressed humantrypsinogen variants that contained various Crotalus-likeactivation peptides, and compared their autoactivation.Results indicate that the Crotalus-like activationpeptides significantly inhibit autoactivation in 0.01-0.1mM Ca 2+ concentrations that is expected to reflect thestorage conditions of trypsinogen in the snake pancreas.The stabilizing effect, however, is diminished in thepresence of 1 mM Ca 2+ , conditions characteristic of thesnake duodenum, where digestion of food takes place.In summary, genetic and biochemical evidence suggeststhat the unique activation peptides of Crotalustrypsinogens confer enhanced stabilization againstpremature autoactivation. We suggest that thisprotective mechanism contributes to the physiologicaladaptation of Crotalus to infrequent feeding.Sajdak, Richard A. 1 , Joshua M. Kapfer 2 , and Craig S.Berg 2,3 . 1 4 Callingham Road, Pittsford, NY 14534,2 Department of Biological Sciences, University ofWisconsin-Milwaukee, 3209 N. Maryland Ave,Milwaukee, WI 53211, 3 Milwaukee County ZoologicalPark, 10001 W. Bluemound Rd., Milw. WI 53226.Habitat selection and home ranges of TimberRattlesnakes, Crotalus horridus, in the upperMississippi River Valley.Nine timber rattlesnakes (4 %%; 3 &&, 2 juveniles[JUV]) were radiolocated from 1999 and 2001 at a sitein western Wisconsin. Habitat and movement data from353 observations (132 %%, 129 &&, 92 juveniles) will beanalyzed to determine movement rates and habitatpreferences. Snakes had radio transmitters surgicallyimplanted into the coelomic cavity. Snakes werereleased at capture sites and re-located at least once perweek during their periods of activity. During each snakelocation, structural and environmental habitat parameterswere recorded. Compared to a set of random plots (RP)(n=56), all three groups were found in secondarywoodland more than expected (19.0% &&, 24.0% %%,39.0% JUV vs 13.0% RP). The greatest disparity was forprairie habitat, (28.0% &&, 2.0% %%, 15.0% JUV), ahabitat type not found in RP (>1.8%).Sumac/dogwood/blackberry shrub habitat was also overutilized(13.0% &&, 5.0% %%, 11.0% JUV vs RP>1.8%). Males were found most often in mature oakwoods (39.0%), but less frequently than expected (43%RP). Males also frequently utilized swamp woodland(24%), at approx. the expected rate (RP 25.0%). Marsh(3.1% &&, 4.0% %%, 0% JUV vs 13.0% RP) andagricultural habitat (0% &&, 1.0% %%, 0% JUV vs13.0% RP) were also under-utilized. Habitat preferencedata (in the form of a chi-squared analysis) andmovement data are currently being analyzed.Sajdak, Richard A. 1 , Craig S. Berg 2,3 , and Robert W.Hay 4 . 1 4 Callingham Road, Pittsford, NY 14534,2Department of Biological Sciences, University ofWisconsin-Milwaukee, 3209 N. Maryland Ave,Milwaukee, WI 53211, 3 Milwaukee County ZoologicalGarden, 10001 W. Blue Mound Rd., Milw. WI 53226,4 Wisconsin Department of Natural Resources,Endangered Resources Program, P. O. Box 7921,Madison, WI 53707.Timber Rattlesnake (Crotalus horridus) dens inWisconsin.46

Descriptions of 7 Timber Rattlesnake dens fromsouthern Wisconsin will be provided. Dens were locatedby tracking radio-equipped rattlesnakes captured on theirsummer ranges and tracked after entering the dens inautumn. Dens varied greatly in such characteristics asshade, direction and steepness of slope. Results of a dentrapping experiment will be presented. Radiolocation isa highly cost effective means of locating dens. Itprovides pinpoint data to help guide den protections andsite management plans. It can also guide land acquisitionand conservation efforts.Sánchez, Elda E 1 ., Jacob A. Galán 1 , Randy Powell 1 ,Julio G. Soto 2 ., William K. Russell 3 , David H. Russell 3and John C. Pérez 1 . 1 Natural Toxins Research Center,Texas A&M University-Kingsville, 920 UniversityBlvd., Kingsville, TX 78363, 2 Department of Biology,San Jose State University-Kingsville, San Jose, CA95112, 3 Laboratory for Biological Mass Spectrometry,Department of Chemistry, P.O. Box 30012, Texas A&MUniversity, College Station, TX 77842-3013Isolation of two disintegrins from Crotalus scutulatusscutulatus (Mojave Rattlesnake) venom lackingMojave toxinDisintegrins are low molecular mass molecules found inthe venom and salivary secretions of four families ofsnakes (Atractaspididae, Elapidae, Viperidae andColubridae). They are non-enzymatic proteins thatinhibit cell-cell, cell-matrix interactions and signaltransduction. Disintegrins have potential in medicalresearch such as treatment for strokes, heart attacks andcancer. They had not been reported in the venom ofCrotalus scutulatus scutulatus (Mojave Rattlesnake) butthe venom has been reported to be either: 1) neurotoxic,2) hemorrhagic, or 3) neurotoxic and hemorrhagic. Inthis study, fourteen Mojave rattlesnakes collected inArizona and Texas were analyzed for the presence of,disintegrin genes and the Mojave toxin genes (bothacidic (Mta) and basic (Mtb) subunits). All venomsamples were also analyzed for the presence ofproteolytic and disintegrin activities. Crude venom wasanalyzed for proteolytic activity, and those with activitywere separated by reverse phase chromatography.Venom fractions were analyzed for disintegrin activityand furthered purified by size exclusion chromatographyfollowed by anion exchange chromatography. Thedisintegrins in these venoms were identified by massspectrometry (MALDI-TOF-TOF) as being homologousto crotratroxin, a disintegrin isolated from the venom ofC. atrox (western diamondback rattlesnake). Genesequence analysis also identified a disintegrinhomologous to crotratroxin. No disintegrin activity ordisintegrin proteins were detected in the venoms of theMojave rattlesnakes containing the Mojave toxin genes.This study has identified the first disintegrins in thevenom of the Mojave rattlesnake that inhibit plateletaggregation in whole human blood.Schofer, Justin, Graduate Student, Department ofBiological Sciences, Northern Arizona University. 740Mesa Trail #4, Flagstaff, AZ. 86001.Population Modeling of Arizona Black Rattlesnakes(Crotalus oreganus cerberus) at a Den Site NearFlagstaff, ArizonaDen sites of the Arizona Black Rattlesnake (Crotalusoreganus cerberus) have been located near the northernextension of their range close to Flagstaff, Arizona.Since 1999, Colorado Plateau Research Stationbiologists have visited the dens regularly in the springand fall. We initiated the first ever mark and recaptureeffort on the species using Passive IntegratedTransponders (PIT) tags. Using this data, I designed apopulation model for this local den site. This project isnovel in that population modeling for rattlesnake speciesis rarely done, and ecological monitoring for Crotalusoreganus cerberus has never been attempted. This pilotproject incorporates numerous methods, models, andprograms, in an attempt to indicate which variables andtheories should be stressed, enhanced, or rejected infuture modeling. Feedback generated from the projectwill be integrated into the model due to the difficultiesand challenges associated with open populations wheredetection probabilities are imperfect or less than one.Seifert, Steven A., Nebraska Regional Poison Center,8401 W. Dodge Rd., Suite 115, Omaha, NE 68114.Recurrence phenomena in antivenom-treatedcrotaline bitesIn the clinical trials of CroFab®, an ovine, Fab crotalineantivenom, prominent and frequent recurrence of bothlocal and systemic effects was observed. Recurrenteffects with other snake antivenoms had been previouslynoted in the occasional case report, but the phenomenonhad not been widely appreciated. With CroFab®, localinjury recurrence was seen in about 50% of patientswithin hours of initial control and persisted or recurredfor up to 24 hours. Recurrence of thrombocytopeniaand/or hypofibrinogenemia occurred in 69% of patientswith initial coagulopathy. It was seen within days ofinitial treatment and persisted or recurred for up to 2weeks. A pharmacodynamic and pharmacokineticmismatch between venom and antivenom components isthe most likely explanation for these phenomena, whichhave now been recognized to occur with all antivenomclasses. The dynamic mismatch occurs becauseantivenom does not initially neutralize all of the venomcomponents in the body. The kinetic mismatch occurswhen venom components remain in the body whileunbound immunoglobulin antivenom fractions areeliminated. The half-life of unbound Fab fragments isquite short compared with that of some venom47

components. F(ab)2 and IgG antivenoms have longerhalf-lives, so antivenom remains in circulation longerand is thus available to neutralize venom coming out oftissue stores. Recurrences with these antivenoms aretherefore generally less common, occur later in thecourse, and are less severe. Following initial control,preventive re-administration of CroFab® in the first 18hours has been shown to prevent or reduce the incidenceof local recurrence. The clinical significance of, andoptimal management strategies for, recurrentcoagulopathies are not clear. Closer monitoring, lateadministration of additional antivenom (with severe,persistent and/or multiple coagulopathies), and othermanagement strategies may be required to overcomesome of the potential adverse results of thesephenomena.Setser, Kirk 1 , David Lazcano Villarreal 2 and AlanKardon 3 . 1 Department of Biological Sciences, Universityof Notre Dame, Notre Dame, IN 46556, USA,2 Laboratorio de Herpetolog , Universidad Aut oma deNuevo Le , A.P. 513, San Nicol de los Garza, Nuevo LeC.P. 66450, M ico, 3 San Antonio Zoo, 3903 N. St. MarySt., San Antonio, TX 78212, USA.Reproductive traits of female Crotalus polystictusLittle information is available concerning thereproductive traits of Crotalus polystictus. As part of along-term, mark-recapture study, we collected data onsize and age of reproductive females, litter number,neonate size, time of parturition, and reproductivefrequency from 102 female C. polystictus encountered inMay-June 2003 and May-July 2004. We collectedfemale rattlesnakes from two neighboring sites withinthe cordillera neovolcanica uplift in the Estado deMexico. We marked and measured snakes prior torelease. Most females were retained in captivity untilparturition. Neonates were marked and measured priorto release. Crolatus polystictus is a fecund rattlesnakewith a rapid reproductive cycle. Some femalesreproduced in their second year, and exhibit an annualreproductive cycle. Litter size was positively correlatedwith maternal size. Differences in litter size betweensites largely resulted from differences in female size.We recorded birth dates from late May through midJuly, corresponding to the arrival of the monsoon rainsin central Mexico.Smith, Jeffrey J. 1 and Matt Goode. 1 1 School of NaturalResources, 104 Biological Sciences East, University ofArizona, Tucson, AZ 85721.A rattler’s tale: inferring a snake’s history throughits rattleAging rattlesnakes from their rattles has long provedproblematic. Unknown rates of ecdysis and rattlebreakage preclude the utility of a rattle as a timepiece.However, segments are added chronologically, andtherefore contain information about the history of anindividual snake. Using data collected from threespecies of rattlesnakes in the Sonoran desert of Arizona,we address several related questions. Initial andsubsequent captures of 136 diamond-backed (Crotalusatrox), 65 black-tailed (C. molossus) and 400 tigerrattlesnakes (C. tigris) provide information on sheddingand growth, and we explore the relationship betweenthese two processes. Because body length is stronglycorrelated with the width of the basal segment, we alsoexamine how rattle segment size relates to factors suchas growth and reproduction. We investigate if sizedifferences between adjacent segments reflect rates ofgrowth and discuss the utility of rattle measurements totest hypotheses concerning growth rates, aging ofindividuals, and age-structure of rattlesnake populations.Smith, Matthew T., Department of Biological Sciences,North Dakota State University, Fargo, ND 58105-5517.A new method for restraining vipers and examples ofits use for morphometric analysisScientists who work with live venomous reptiles havethe usual concerns of obtaining accurate measurementsplus the added pressure of maintaining safety for boththemselves and the specimens that they work with. Anymethod used to restrain venomous reptiles shouldminimize: stress to the animal, the chance of injury toboth the researcher and the animal, and the degree oferror associated with any measurements taken. A recentarticle in Herpetological Review assessed the accuracyof SVL measurements taken in “squeeze boxes”, atechnique that is widely used and rarely questioned.While conducting research on prairie rattlesnakes(Crotalus viridis viridis), I developed a new techniquefor restraining rattlesnakes. The method should alsowork with other vipers, which have wide heads, but maynot be suitable for elapids or venomous colubrids. Thetechnique affords a researcher the opportunity to handlea rattlesnake while reducing stress and increasing safetyfor both the snake and the handler while, at the sametime, improving the accuracy of measurements on livesnakes. Using this new procedure I have examined thestandard error incurred during measurements anddescribe its potential for use in many types of analysis.Examples of measurements obtained and geometricmorphometric analyses of head shape are included.Smith, Ronald M., Walter F. Bien., and James R.Spotila. Department of Bioscience & Biotechnology,Drexel University, 3141 Chestnut St., Philadelphia, PA19104Spatial Ecology of the Timber Rattlesnake in thepinelands of southern New JerseyThe timber rattlesnake (Crotalus horridus) is a stateendangered species in the Pinelands of southern NewJersey. The Warren Grove Gunnery Range (WGR),48

located in Burlington County, New Jersey, occupies9400 acres of upland pine-oak forests, wetlands, anddisturbed sites as a result of military operations. Weconducted a study at WGR to better understand thespatial ecology of timber rattlesnakes and to determineif military operations impacted this newly discoveredpopulation. Key objectives of the study were to estimatepopulation size, monitor home range movements,determine habitat preference, locate areas of high useand record locations of hibernacula. During this study(fall 2002 through fall 2004), we pit-tagged 24individuals and monitored the home range andmovements of 3 female and 6 male radio-implantedtimber rattlesnakes. Sixty seven percent of relocationswere in wetlands and 30% were in uplands. All of theupland relocations were within 75 meters of wetlandhabitats. Male snakes had larger home ranges (89 ha)than females (60.5 ha), including larger core areas, 26 haand 9 ha respectively. Disturbed habitats (i.e. openfields) accounted for 27% of upland relocations. Mostdisturbed sites were located within core areas wheredisturbance provided good habitat for foraging, basking,and brooding of gravid females. Military operations didnot impact the timber rattlesnake population. A betterunderstanding of the spatial ecology of the timberrattlesnake at WGR will help natural resource managersto protect this state endangered species and to maintainmilitary readiness. As a result of this research, aconservation plan has been proposed at WGR thatincludes protection of large contiguous critical habitatand important use areas from potential impacts fromroad maintenance, prescribed burning, gravel extraction,and related military operations.Smith, Tamara L. 1 and Kenneth V. Kardong 2 . 1 Centerfor Teaching, Learning, and Technology, WashingtonState University, Pullman, WA 99164-4550, 2 School ofBiological Sciences, Washington State University,Pullman, WA 99164-4236.Binary cues in rattlesnake poststrike trailingRattlesnake predatory behavior relies heavily, but notexclusively, upon chemical cues. Rattlesnakes strike andusually release rodent prey. The envenomated prey,dashing off until the onset of immobilization and death,must then be relocated. During poststrike relocation,rattlesnakes possess extraordinary chemosensory acuity,being able to discriminate the scent trail of theenvenomated mouse from even that of littermates.Prestrike, chemosensory information is also used,presumably in locating areas of high prey concentration.Poststrike, trailing behavior is mediated by two distinctsets of chemosensory cues and thus representfunctionally (and phylogenetically) distinct modules ofbehavior. With a successful strike the rattlesnake carriesback the inherent odor of the mouse and adds to this theinduced odor produced with envenomation.Consequently, rattlesnake trailing-acuity is based upona system of two behavioral modules – one basal and onederived - related to a binary set of chemosensory cues.Snider, Andrew T. 1 , Yu Man Lee 2 , Daria Hyde 3 , andRebecca Christoffel 4 , 1 Curator of Herpetology, DetroitZoological Institute, P.O. Box 39, Royal Oak, MI48068, 2 Associate Program Leader-Zoology, MichiganNatural Features Inventory, Michigan State UniversityExtension, P.O. Box 30444, Lansing MI 48909-7944,3 Associate Program Leader-Conservation Planning,Michigan Natural Features Inventory, Michigan StateUniversity Extension, P.O. Box 30444, Lansing, MI48909-7944, 4 Doctoral Student, Dept. of Fisheries andWildlife, Michigan State University, 13 NaturalResources Building, East Lansing, MI 48824The Eastern Massasauga, Sistrurus c. catenatus, inMichigan: conservation through educationThe Eastern Massasauga, Sistrurus c. catenatus, isconsidered a “Species of Special Concern” in Michigan,and is listed as “Threatened” or “Endangered”throughout the remainder of its range in the U.S. andCanada. In addition, it is a candidate for federal listing,and is the subject of a new Candidate ConservationAgreement with Assurances (CCAA) in Michigan. In2003, with funding from the U.S. EnvironmentalProtection Agency, a collaborative partnership betweenthe Michigan Natural Features Inventory, MichiganState University, the Michigan Dept. of NaturalResources, the Detroit Zoological Institute, and theToronto Zoo launched a multi-faceted massasaugaeducation and outreach effort in a four-county area insoutheast Michigan. This project, modeled after thesuccessful massasauga education program in Ontario,includes an assessment of public attitudes, developmentand distribution of educational materials, presentation ofeducational workshops, and the development of a localvolunteer snake responder network. To date, we haveconducted 6 workshops for landowners and the generalpublic and 7 workshops for natural resourceprofessionals. These workshops and programs will becontinued in 2005, and may be expanded to includeother interested parties. In addition, a full-color posterhas been produced, a website has been created, and abrochure is being revised for reissue.Spencer, Carol L. Museum of Vertebrate Zoology,University of California, Berkeley, CA 94720.Geographic Variation In the Morphology of Crotalusatrox, the Western Diamondback Rattlesnake:Evidence For a Widespread SpeciesStudies of geographic variation within species areimportant for identifying speciation processes and itscauses. Crotalus atrox is widespread, yet no large-scalestudy of variation among populations has beenundertaken. The objective of this study was to evaluate49

variation in morphology across its range. Thirty-sevenmeristic, mensural and categorical morphologicalcharacters from 673 adults were analyzed using principalcomponents analysis and discriminant function analysis.Many traits varied within the Eastern, Western andMiddle groups, as well as among these groups. Mensuraltraits were highly variable among regions, and there wasonly a slight trend in body size to be higher in the north.Other characters that showed clinal variation wereventral scale counts, which increased with decreasinglongitude, and the number of scales before thesupraoculars, which were higher in the east. Variation innon-mensural data was better explained along alongitudinal cline, possibly due to environmentaldifferences. Crotalus atrox may truly be a generalistspecies. It seems to vary little across its range in termsof morphological traits, prey eaten or reproductiveoutput. The most differences were seen across an east towest continuum, with variation within groups. A numberof recent studies on various vertebrate taxa show speciesdivisions across this same continuum. Crotalus atroxrepresents a species with a large geographic range sizewith phenotypic variation throughout its range, makingit a good model organism for further studies ofenvironmental effects and biogeographical processesacross western North America.Straight, Richard C. Protherics-Utah and Departmentsof Medicine and Surgery, University of Utah, Salt LakeCity, UT 84108Antivenom(immunoglobin) development, testing,production and use for clinical serotherapy of pitviper(rattlesnake) envenomationsIt is generally recognized that serotherapy usingmammalian immunoglobulin preparations, specific tosnake venom antigens, is the most effective and safestclinical therapy for snake envenomations. Relevantfactors related to antibody development and use forserotherapy include: A. Antibody development,preparation, and preclinical testing. 1. The selection ofvenom antigens. 2. The selection of the host animal tobe immunized. 3. The immunization protocol. 4. Thetype of antibody or antibody fragment [IgG, F(ab’)2,Fab]. 5. Preparation and purification of antibodies andantibody fragments. 6. Potency(antigen specificity,crossreactivity, binding affinity, titre). 7. Solubility andStability. 8. Safety--Immediate and delayed allergicresponses, organ damage. B. Clinical testing and use--safety and effectiveness. 1. Venom antigens--type andamount. 2. Site of envenomation. 3. Time elapsed fromenvenomation. 4. Method of serotherapy--route, dose,and dose rate of antibody administration. 5. Thepharmacodynamic mechanisms of neutralization andelimination of toxic venom proteins. 6.The relativepharmacokinetic behavior of the immunoglobulinantibody protein components, the venom antigen(toxin)protein components, and the antibody-antigen boundcomplexes in the blood and lymph vascular system.>Consideration of these factors in the light of currentknowledge of the biochemical and pharmacologicalproperties of venom antigens(toxic proteins) andantivenom antibody components [IgG, F(ab)'2, Fab] hasresulted in safer more effective antivenoms and a betterunderstanding of their clinical use for more effectiveserotherapy. The data suggest that safety andeffectiveness for serotherapy of antivenom products[IgG, F(ab'), Fab] of equivalent potency andtitre depend on their level of purity, their biochemicaland pharmacokinetic properties in relation to therelevant venom toxins, and how they are used clinically.Taylor, Emily N. and Dale F. DeNardo. School of LifeSciences, Arizona State University, Tempe, AZ 85287Why are male rattlesnakes larger than females?In most rattlesnake species, adult males are heavier andlonger (snout-vent length) than females. Thepredominant hypothesis for this sexual size dimorphism(SSD) is sexual selection for large males, since malerattlesnakes fight for access to females. Anothercomplimentary hypothesis is that it is beneficial forfemales to be smaller than males because small femaleshave low metabolic costs of maintenance, allowing themto accumulate energy stores rapidly and reproducefrequently. Alternatively, SSD may be the result ofphenotypic plasticity rather than natural selection, withfemales growing more slowly than males because theyhave higher energetic costs of reproduction, leaving lessenergy available for growth. Identification of theproximate, physiological mechanism responsible forSSD would help elucidate the evolutionary andecological significance of SSD in rattlesnakes. I haveconducted a series of experiments to examine how maleWestern Diamond-backed Rattlesnakes (Crotalus atrox)become larger than females. Male neonates are slightlylarger than females, but this difference does not accountfor the extreme difference in size observed in adultsnakes. Testosterone does not appear to stimulate growthin male C. atrox, as it does in many other vertebrates, ascastrated free-ranging males grow at the same rate assham-operated males. Males and females raised oncontrolled diets in the laboratory grow at the same ratesand never diverge in size, with both sexes growing tosizes much in excess of free-ranging snakes. Similarly,supplementation of the diets of free-ranging femalesleads to dramatic increases in growth. It thereforeappears that SSD in C. atrox is the result of phenotypicplasticity, since females are capable of growing to malelikesizes. If this is true, then the natural selectionhypotheses for SSD in rattlesnakes may not besupported.50

Waldron 1 , Jayme L., Shane M. Welch 1 , StephenBennett 2 , Wade Kalinowsky 2 , Michael E. Dorcas 3 , andDrew Lanham 1 , 1Dept. of Forestry and NaturalResources, 262 Lehotsky Hall, Clemson University,Clemson, SC 29634, 2 South Carolina Dept. of NaturalResources, Rembert C. Dennis Building, 1000 AssemblyStreet, Columbia, SC 29201, 3 Dept. of Biology,Davidson College, Davidson, NC 28035-7118.A multiscale examination of habitat use by sympatricpopulations of eastern diamondback rattlesnakes andcanebrake rattlesnakes in the South Carolina coastalplain.Central to the conservation of a species is theidentification of habitat parameters associated with thespecies distribution. We used radio telemetry data,logistic regression, and GIS to model habitat use versusavailability at two spatial scales for sympatricpopulations of eastern diamondback rattlesnakes(Crotalus adamanteus) and canebrake rattlesnakes (C.horridus) in the South Carolina coastal plain. Habitat usewithin home range, as defined by Minimum ConvexPolygons (MCP), was modeled at the landscape basedon habitat availability within the study area. At thesecond scale, individual snake locations were used tomodel habitat use within snake home ranges.Observations were based on 20 eastern diamondbacks (6males and 14 females) and 18 canebrakes (8 males and10 females) that were telemetered between 1997 and2004. Potential predictor variables were based onvegetation structure, edaphic characters, and landscapetopography. Preliminary results indicate that, at thelandscape, male canebrake habitat use was associatedwith proximity to fields and bottomland forests. Femalecanebrake habitat use was associated with soil textureand soil drainage. Other significant predictors forfemales included proximity to bottomland forests andfield edges. Our analysis failed to detect selection foreither male or female canebrakes within their homeranges. At the landscape, male eastern diamondbackhabitat use was associated with proximity to fields andgreater distances from hardwood bottoms. Femaleeastern diamondback habitat use was predicted by thepresence of open-canopy pine forests and proximity tofields. Within home ranges, both male and femalediamondbacks were negatively associated withbottomland forests. Further, male diamondbacks usedwell-drained soils and open-canopy pine forests.Weaver, Robert E. and M. E. Lahti. Department ofBiological Sciences, Central Washington University,400 E. University Way, Ellensburg, WA98926Diet of the Northern Pacific Rattlesnake (Crotalusviridis oreganus) in the Yakima River Canyon ofCentral Washington StateWe investigated the diet of a population of the NorthernPacific Rattlesnake (Crotalus viridis oreganus) incentral Washington state. A total of 74 prey items wasidentified from 304 snakes collected as either dead-onroad(DOR) or alive-on-road (AOR) from May throughOctober 2003 and 2004. Snakes were measured,weighed and placed into three size classes; 60 cm. The stomachs and intestinal tractsof DOR snakes (n = 284) were examined for prey itemsand fecal material. The stomachs of all AOR snakes (n= 20) were palpated to collect any prey items, whichwere identified to the lowest taxonomic level, weighedand preserved. Small mammals (e.g. deer mice(Peromyscus maniculatus) Great Basin pocket mice(Perognathus parvus) and voles (Microtus spp.)) werethe most frequent prey item in the diet (74 %) followedby lizards (20 %) and birds (6%). Predator-prey massratios ranged from 0.02-0.94. Larger snakes did notnecessarily ingest larger prey items, but do have a morediverse diet. Diet was independent of sex, but not sizeclass. Snakes contained multiple prey items (2-6) fromApril to June, but rarely later in the season. In addition,we compare our data with other populations of C. v.oreganus in the Pacific Northwest.Werman, Steven D., Department of BiologicalSciences, Mesa State College, 1100 North Ave., GrandJunction, CO 81501.A phylogenetic perspective on the evolution of thebiological properties of rattlesnake venomOver the past decade, considerable progress has beenmade on refining a phylogenetic hypothesis of therattlesnakes, based on molecular genetic information.Given a rather stable picture of rattlesnake relationshipand evolution it is possible to consider the evolution ofvenom and venom components in light of thesehypotheses and independent of gene tree analyses. Thispaper will focus on the phylogenetic patterning ofbiological properties of rattlesnake venom based on atemplate of species relationships based on a molecularphylogeny. Considered here are characteristics andfeatures of venom important to hemorrhage, edema,myonecrosis, neurotoxic effects, cardiovascular andhemostatic changes. In spite of the large range of knownvariation in venom action at the population andinterspecies level, general patterns of venom evolutionconsistent with species phylogeny may emerge.Wiley, Kristen L. and James R. Harrison, KentuckyReptile Zoo, 200 L and E Railroad, Slade, KY 40376.Venom production from Crotalus: EstablishingstandardsRattlesnake venoms are currently valuable forbiomedical research and antivenom production. Due toour increased understanding of geographic variation andpathogen content of venoms, Kentucky Reptile Zoo isdeveloping standards of venom production for use inhumans. Standards are necessary to ensure cleanliness,51

continuity of venom composition and volume, definiteorigin of components, and possibility of replication.Creating standards when many inherent variables exist,as is the case with snakes and venom, is challenging.Captive breeding, records maintenance, properhusbandry, and familiarity with venom variation are allnecessary to establish and maintain the standards. Theend result is venom that is stable in composition overseveral extraction cycles, meets cleanliness standards,and is traceable to individual animals and geographiclocales: all properties which are valuable to researchscientists.Young, Bruce A. (Washington State University)What it takes to Meter VenomVenom metering is the hypothesis that rattlesnakes canactively control or regulate their venom injection in sucha way that the dosage of venom is adjusted depending onsuch factors as the size and species of the prey. Thispresentation will examine the underlying ecologicalassumptions of venom metering, as well as themechanistic bases for the regulation of venom injection.The ultimate goal of the presentation is to explore whatwe actually know about the regulation of venominjection in snakes, and what we need to learn to extenda quantitative analysis of venom allocation back to theecological argument of venom metering.Zappalorti 1 , Robert T., and Howard K. Reinert 2 .1 Herpetological Associates, Inc., 575 Toms River Road,Jackson, New Jersey 08527 and 2 Department ofBiology, College of New Jersey, Trenton, New Jersey,08650.Habitat Use, Foraging Behavior, and OverwinteringSites of Timber Rattlesnakes (Crotalus horridus) inthe New Jersey Pine BarrensTimber rattlesnakes were studied in the Pine Barrensfrom 1983 to 1993 by visual searching and radiotelemetry.Observations were made on habitat use,ambush locations, feeding events, and hibernation sites.Timber rattlesnakes used pine-oak, oak-pine, and pitchpine lowlands as summer foraging habitat. White-footedmice, pine voles, and meadow voles were important preyitems, but chipmunk, red squirrel, gray squirrel, andcottontail rabbit were also eaten by adult rattlesnakes.Most rattlesnakes in the study population usedunderground rodent burrows and natural spaces underthe root-systems of cedar, sour gum, and red maple treesalong stream edges for winter refuge. The groundsurface at hibernacula is often covered with a thickcarpet of Sphagnum moss, in densely vegetated Atlanticwhite cedar stands. Preliminary highlights of thisinvestigation include the first observation of 2 neonateC. horridus hibernating in an artificial den, similar to thetype described in Zappalorti and Reinert in1994. Thiswas the first time Pine Barrens rattlesnakes wereobserved hibernating in an upland situation. One of thetwo individuals was radio-tracked for two successiveyears. In the fall of 1995, it shifted hibernation sites toa more typical situation at the stream-edge of the cedarswamp, and returned to the same general location againin the winter of 1996. Another first-time observationinvolves the shift from one overwintering stream toanother by a post-partum female in the study area duringthe winter of 1995. On 4 April 1995, an extensive forestfire burned approximately 20,000 acres of Pinelandsforest in our study area. After emerging from heroverwintering burrow in late April1995, she movedsouth through the burnt forest ~ 1.6 kilometers. Sheremained there for about one month, then moved 25meters east along the edge of second major stream to ahuman-made mound on a field-edge. After giving birthto 12 young, the post-partum female moved ~ 0.8kilometers southwest, towards the stream on thesouthern edge of the study area. This location is whereshe overwintered in 1995 - 1996. This was the firstobservation of a Pine Barrens rattlesnake shifting streamcorridors to hibernate. Such behavior has importantimplications because it demonstrates non-fidelity to aparticular stream corridor, the importance of adjacentstream corridors, and suggests an understanding of thesurrounding available habitat on the part of therattlesnake. This shifting of an overwintering sitesuggests that some rattlesnakes may be more pioneeringthen previously thought. It should be noted that the areawhere she hibernated in Fall of 1995 was engulfed bythe fire, whereas the 1996 stream location, ~ 2.4kilometers to the south, was not burnt.52