HABITAT SUITABILITY INDEX MODELS: PILEATED WOODPECKER

FWSJO BSe82l1 0.39APRIL 1983HABITAT SUITABILITY INDEX MODELS:PILEATED WOODPECKERNATIONAL WETLANrsRESEARCH CENTER LIBRARY700 C(//undome B/vliLafayette, LA 70506-3152~2-10.39Fish and Wildlife Serviceu.s. Department of the Interior

This model is designed to be used by the Division of Ecological Servicesin conjunction with the Habitat Evaluation Procedures.

FWS/OBS-82/10.39April 1983HABITAT SUITABILITY INDEX MODELS: PILEATED WOODPECKERbyRichard L. Schroeder107 N. HollywoodFort Collins, CO 80521Project OfficerR. Charles SolomonWestern Energy and Land Use TeamDrake Creekside Building OneU.S. Fish and Wildlife Service2627 Redwing RoadFort Collins, CO 80526Western Energy and Land Use TeamDivision of Biological ServicesResearch and DevelopmentFish and Wildlife ServiceU.S. Department of the InteriorWashington, DC 20240

This report should be cited as:Schroeder, R. L. 1982. Habitat suitability index models: Pileated ,,000-peeker. U.S. Dept. Int., Fish 'Wildl. Servo PWS/OBS-82/10.39. 15 pp.

PREFACEThis document is part of the Habitat Suitability Index (HSI) Model Series(FWS/OBS-82/10), which provides habitat information useful for impact assessmentand habitat management. Several types of habitat information areprovided. The Habitat Use Information Section is largely constrained to thosedata that can be used to derive quantitative relationships between key environmentalvariables and habitat suitability. The habitat use information providesthe foundation for HSI models that follow. In addition, this same informationmay be useful in the development of bther models more appropriate to specificassessment or evaluation needs. .The HSI Model Section documents a habitat model and information pertinentto its application. The model synthesizes the habitat use information into aframework appropriate for field application and is scaled to produce an indexvalue between 0.0 (unsuitable habitat) and 1.0 (optimum habitat). The applicationinformation includes descriptions of the geographic ranges and seasonalapplication of the model, its current verification status, and a listing ofmodel variables with recommended measurement techniques for each variable.In essence, the model presented herein is a hypothesis of species-habitatrelationships and not a statement of proven cause and effect relationships.Results of model performance tests, when avail abl e, are referenced. However,models that have demonstrated reliability in specific situations may proveunreliable in others. For this reason, feedback is encouraged from users ofthis model concerning improvements and other suggestions that may increase theutility and effectiveness of this habitat-based approach to fish and wildlifeplanning. Please send suggestions to:Habitat Evaluation Procedures GroupWestern Energy and Land Use TeamU.S. Fish and Wildlife Service2627 Redwing RoadFt. Collins, CO 80526iii

CONTENTSPREFACEAC KNOWLEDGMENTS ...•..............•.....................................iiivHABITAT USE INFORMATION 1Genera 1 1Food ......•.......•............................................... 1Water .•..................•......... ;............................... 2Cover 2Reproduction 2Interspersi on ...............•..................•.................. 5Special Considerations............................................ 5HABITAT SUITABILITY INDEX (HSI) MODEL... ....•.....•..... 5Mode 1 App 1i cab i 1i ty ....•....•..................................... 5Mode 1 Descri ption ..•..•........................................... 6Model Relationships.................... ........•.......•........... 8Application of the Model.......................................... 11SOURCES OF OTHER MODELS ..•......."...................................... 13REFERENCES ......••.....•.....•...•...........•.......•....•.••......... 14iv

ACKNOWLEDGMENTSWe gratefully acknowledge Evelyn Bull and Richard Conner for their reviewof this habitat model. Funds for the development of this model were providedby the U.S. Fish and Wildlife Service Regional Office in Portland. Publicationcosts of this model were partially paid for by the U.S. Army Corps ofEngineers. The cover of this document was illustrated by Jennifer Shoemaker.Word processing was provided by Carolyn Gulzow and Dora Ibarra ..v

PIlEATED WOODPECKER (Oryocopus pileatus)HABITAT USE INFORMATIONGenera1The pileated woodpecker (Oryocopus pileatus) inhabits both coniferous anddeciduous forests, but is restricted to ar~as containing mature, dense, productivestands (Bock and lepthien 1975). These woodpeckers are widely distributedin eastern forests, but are confined in the West to Washington, Oregon, andnorthern California and, in the Rocky Mountains, to northern Idaho and northwesternMontana (McClelland 1979). Their absence in the central and southernRocky Mountains is due to a lack of dense, highly productive forests withrapid maturation and decay (Bock and lepthien 1975).The critical components of pileated woodpecker habitat are large snags,large trees, diseased trees, dense forest stands, and high snag densities(Bull 1975).FoodPileated woodpeckers depend heavily on carpenter ants (Camponotus spp.)and other wood-boring insects for food (McClelland 1979; Bull 1981). A studyof the stomach contents of 80 pil eated woodpeckers from across the UnitedStates, and over the entire year, showed that animal foods comprised about 73%of the diet and vegetable food the remainder (Beal 1911). Over one-half ofthe animal food was ants, with beetles the next most abundant food item. Themajority of the vegetable food was wild fruits.Pileated woodpeckers in Oregon fed by excavation (subcambial penetration)approximately two-thirds of the time, and by scaling ba rk , in search ofinsects, the remainder (Bull 1981). Woodpeckers in Virginia fed primarily bypecking (no subcambial penetration) and excavating during the breeding season,but used excavation techniques more than 70% of the time during the wintermonths (Conner 1979a). This seasonal variation and narrowing in breadth offoraging techniques is due to the availability and location of prey itemsduring winter months (Conner 1979a, 1981).Pileated woodpeckers choose foraging habitats that contain high densitiesof logs and snags, dense canopies, and tall shrub cover (Bull and Meslow1977). They forage on snags, stumps, and logs that exceed 18 cm (7 inches) indiameter (Bull and Meslow 1977), although they prefer logs greater than 25 cm(10 inches) in diameter and greater than 15 m (49 ft) in length (Bull 1981).1

Bull (1981) reported that pileated woodpeclr.ers in Oregon spent 36~ of their~feeding time foraging on logs. 35% on live trees, and 29% on snags. Foragingsites on the ground were in dead and decayed material. most of which had les~than 25% of the barlr.. branches. and needles remaining. The majority of snagsused for foraging were greater than 51 cm (20 inches) dbh. while only 46% oflive trees used for foraging exceeded that diameter. Pileated woodpeclr.ers inthis study fed mostly on carpenter ants, which were more abundant in largerdiameter dead wood.Pileated woodpeclr.ers in Virginia foraged mostly on dead wood in matureforest habitats (Conner 1980). Pil eated woodpeclr.ers foraged extens i velyonfallen logs in a recently burned pine forest in Mississippi (Schardien andJaclr.son 1978). Tree stumps greater than 0.3 m (l ft) in height are usedextensively as foraging sites in the East and West (Conner; pers. comm.). Useof snags for foraging increased during the winter months in Montana. as logsand stumps became snow covered (McClelland 1979). Winter food supply wasprobably the limiting factor for·pileated woodpeclr.ers in this northern studyarea. However. Bull and Meslow (1977) noted. in their Oregon study area, thatfeeding habitat was probably not as critical as nesting habitat.WaterPileated woodpeclr.ers have been observed to dri nk water before roost i ngfor the night (Kilham 1959). Pileated woodpeclr.ers in Virginia did not nestfarther than 150 m (492 ft) from water, and most nests were within 50 m(164 f t ) of water (Conner et a1. 1975). The" average di stance between watersources in this study area was 600 m (1,969 ft). The distribution of pileated ~woodpeclr.ers in this area may have been due to the fact that mesic environmentsproduce more large trees at a faster rate than xeric sites.CoverCover requirements of the pileated woodpeclr.er are very similar to theirreproductive requirements. Therefore. cover requirements are included in thefollowing section.ReproductionPileated woodpeckers are primary cavity nesters that require large snagsfor their nest site (Bull 1981). In Oregon. these woodpeclr.ers selected nestsnags from groups of snags in areas of dense forest (Bull and Meslow 1977).They excavate a new cavity each spring and, therefore, need a continual supplyof new snags (Bull 1975). Pi 1eated woodpecker-s have the strongest year-roundpair bond of any North American woodpecker (Kilham 1979), and pairs appear tooccupy the same location in successive years (Kilham 1959).Pileated woodpeckers nest tree search image in Montana was summarized byMcClelland (1979:291, 294) as: "a broken top snag [Western larch (Larixoc~identalis), ponderosa pine (Pinus ponderosa), or black cottonwood (PopulUStrlchocarpa)] at least 60 cm (24 inches) dbh, taller than 18 m (59 ft) (usually2

The majority of nest trees in Oregon had less than 25~ of their originallimbs and bark remaining (Bull 1981). Thirteen of eighteen nest trees inVirginia were dead, one had a living cambium but decayed inner core, and four /nests were in dead parts of live trees (Conner et al. 1975). Pileated woodpeckersin Virginia were apparently able to detect the presence of heart rotin trees, and selected such trees as nest sites, thus reducing the energyexpenditure required for excavation (Conner et a1. 1976).Several researchers have estimated the number of snags needed to supportmaximum pi1eated woodpecker populations. Bull and Mes10w (1977) reported thatoptimum habitats in Oregon should contain sound snags greater than 51 cm(20 inches) dbh at a density of 0.35 snag/ha (0.14 snag/acre). Their estimatewas based on the following assumptions: (1) a density of two pairs of pileatedwoodpeckers per 2.59 k.m 2 (1.0 mP); (2) a need for three snags per year perpair, on~ for nesting and two for roosting; and (3) a need for a reserve of 15snags for each snag used because not all snags are immediately acceptable.Thomas et a1. (1979) stated that optimum pileated woodpecker habitat containedsnags greater than 50.8 cm (20 inches) dbh and taller than 9.5 m (31 ft) at adensity of 0.32 snag/ha (0.13 snag/acre)." This estimate assumes a territorysize of 122 ha (300 acres). Optimum pileated woodpecker habitat in the northeasternUnited States has been characterized as containing snags 45 to 65 cm(18 to 26 inches) dbh and 12 to 21 m (39 to 69 ft) tall at densities of 0.6snag/ha (0.24 snag/acre) (Evans and Conner 1979). This estimate assumes thefollowing: (1) a territory size of 71 ha (175 acres) per pair of pileatedwoodpeckers; (2) a need for four snags per year per pair; one for nesting, twOfor roosting, and one for fledged young; and (3) a need for a reserve of 10snags for each snag used to account for unusable snags, replacements, feedinghabi tat needs, and a snag supply for secondary users. ~Pi1eated woodpecker densities in Illinois were positively correlated withthe number of large trees [greater than 56 cm (22 inches) dbh] (Graber eta1.1977). Woodpecker densities were highest when there were about 50 largetrees/ha (20/acre). and the approximate average dbh was 29 cm (11.5 inches).Woodpecker densities were lowest when there were only about 12.5 large trees/ha(5/acre) and the approximate average dbh was 27 cm (l0.5 inches). [Note:Average dbh figures were estimated from graphics in Graber et al. (1977).using the median value of the size classes provided.] Conner (pers. comm.)stated that optimum suitability exists when habitats contain 30 or more treesgreater than 51 cm dbh/0.4 ha (20 inches dbh/1.0 acre).Pileated woodpeckers in Virginia preferred to nest in mesic stands nearstreams wi th the fo 11 owi ng characteri sti cs: greatest basa 1 area [27.1 m 2/ha(118 ft 2/acre)], greatest stem density [475.3/ha (1,174/acre)], and highestcrown canopy height [24.2 m (79.4 ft)] available (Conner and Adk.isson 1976).Favored nesting habitat in Montana and Oregon was dense forests containing oldgrowth western larch or ponderosa pine (McClelland 1979; Bull 1981). Douglasfir(Pseudotsuoa menziesii) was seldom used in either study, probably due tothe fact that its sapwood decayed very rapidly (McClelland 1979; Bull, pers.comm.) .4 /

InterspersionThe minimum forest size needed to support pileated woodpeckers ispartially dependent on the availability of food (McClelland 1979). A minimumof 200 ha (494 acres) is probably needed in northern Rocky Mountain areas.Nesting pairs in Oregon- ranged over 130 to 243 ha (320 to 600 acres), and aminimum requirement of 130 ha (320 acres) has been suggested (Bull and Meslow1977). The winter foraging range of a pair of pileated woodpeckers in thesoutheastern United States was 70 ha (173 acres) (Kilham 1976).Special ConsiderationsThe pileated woodpecker is a key indicator species for the retention of acomplete community of hole nesting birds (McClelland 1979), and it is likelythat, if the habitat needs of the pileated woodpecker are met, other woodpeckersalso would benefit (Bull and Meslow 1977).Habitat for the pileated woodpecker in the Rocky Mountains is diminishingas old growth forests are cut (McClelland 1979). Silvicultural thinning maynegatively affect these woodpeckers due to a loss of decayed trees that providewoodpecker nest sites and habitat for carpenter ants (Conner et al. 1975).Pileated woodpecker habitat may also be threatened by intensive forest harvestingpractices (Conner 1980). A cutting rotation in Eastern forests of 80years would probably provide adequate foraging habitat (Conner 1980), but a150 year rotation may be needed for nesting habitat (Conner 1978).Unmanaged, mature stands usually have adequate numbers of snags forresident woodpeckers (Bull et al . 1980). In managed forest stands, snags canbe maintained by killing trees or by leaving trees to die, and woodpeckers canthen be managed at selected population levels.HABITAT SUITABILITY INDEX (HSI) MODELModel ApplicabilityGeographic area. This model was deveToped for application within theentire range of the pileated woodpecker with different variables included forsnag diameters for the eastern and western portions of the range.Season. This model was developed to evaluate the year-round habitat ofthe pileated woodpecker.Cover types. This model was developed to evaluate habitat quality in thefollowing cover types: Evergreen Forest (EF); Deciduous Forest (DF); EvergreenForested Wetland (ERY); and Deciduous Forested Wetland (DRY) (terminologyfollows that of U.S. Fish and Wildlife Service 1981).5

Minimum habitat area. Minimum habitat area is defined as the mi mmumamount of contiguous habitat that is required before a species will occupy anarea. It is assumed that a minimum of 130 ha (320 acres) of habitat mustexist or the HSI for the pileated woodpecker will equal zero.Verification level. Previous drafts of this model were reviewed byEvelyn Bull and Richard Conner, and their comments were incorporated into thecurrent draft (Bull, pers. comm.; Conner, pers. comm.).Model DescriptionOverview. The food, cover, and reproductive habitat needs of the pileatedwoodpecker are very similar. Large snags provide a source of food, cover, andnest sites. Mature, dense forest stands contribute to both the food and coverneeds of the pileated woodpecker. Therefore, this model combines food, cover,and reproduction into a single component. It is assumed that the presence ofwater is related to the variables used to assess food, cover, and reproduction.Pi 1eated woodpeckers use differePlt si ze snags in the eastern and westernportions of their range, and this model 'includes specific variables for eacharea.The relationship between habitat variables, life requisites, cover types,and the HSI for the pileated woodpecker is illustrated in Figure 1.The following sections provide a written documentation of the logic andassumptions used to interpret the habitat information for the pileated woodpeckerir. order to explain the variables that are used in the HSI model.Specifically, these sections cover the following: (1) identification ofvariables used 1n the model; (2) definition and justification of the suitabilitylevels of each variable; and (3) description of the assumed relationshipbetween ~ariables.Food/cover/reproduction comoonent. Dense, mature forest stands with anabundance of logs and stumps, and large decayed snags provide food and coverfor the pileated woodpecker. This model assumes that either the availabilityof dense, mature forests or the abundance of snags can be the limiting factorin determining habitat values for pileated woodpeckers.The density and maturity of forest stands can be assessed by measuringthe tree canopy closure, abundance of large diameter trees, and abundance offallen logs and stumps. Pileated woodpeckers prefer dense stands, and it isassumed that optimum habitats have 75~~ or greater tree canopy closures andthat stands with less than 25% canopy closure will have no suitability.Pileated woodpeck.ers are most abundant in forest stands with many largediameter trees. It is assumed that optimum habitats contain 30 or more treesgreater than 51 cm dbh/0.4 ha (20 inches dbh/l.O acre). Habitats with lessthan three such large trees per 0.4 ha (1.0 acre) are assumed to have nosuitability. Optimum pileated woodpecker habitats ccntat n an abunaance offallen logs and stumps, while habitats with no fallen logs or stumps mayprovide moderate suitability if other resources are available. It is assumed6

Habitat variableLife reguisiteCover typesPercent tree canopyclosure------"-1Number of trees > 51 cm(20 inches) dbh/0.4(1.0 acre)---~Number of tree stumps> 0.3 m (1 ft) inheight and> 18 cm(7 inches) diameterand/or logs> 18 em(7 inches) diameter/0.4 ha (1.0 acre).------~Number of snags > 38 cm(15 inches) dbh/0.4 ha(1.0 acre) (easternportion of range only).Food/Cover/-----­ReproductionEvergreen ForestDeciduous ForestEvergreen ForestedWetlandDeciduous ForestedWetland--HSIAverage dbh of snags> 38 cm (15 inches)dbh (eastern portionof range only).Number of snags > 51 cm(20 inches) dbh/0.4 ha(1.0 acre) (westernportion of range only).Average dbh of snags> 51 cm (20 inches)dbh (western portionof range only).Figure 1. Relationship of habitat variables, life requisites,and cover types in the pi1eated woodpecker model.7

that maximum habitat values occur when there is a total of 10 or more logsgreater than 18 cm (7 inches) diameter and/or stumps of the same diameter andgreater than 0.3 m (1 ft) in height per 0.4 ha (1.0 acre). Overall suitability.\related to the density and maturity of forest stands is a function of the treecanopy closure, abundance of large trees, and abundance of logs and stumps.Tree canopy closure and large tree abundance are the most important variables,while log and stump abundance exerts less of an influence in determininghabi tat va1ues.Snag sui tabil i ty is assumed to be related to the abundance of 1argediameter snags. It is assumed that pileated woodpeck.ers, in the Easternportion of their range, require snags greater than 38 cm (15 inches) dbh fornesting and, in the West, they require snags greater than 51 cm (20 inches)dbh. Maximum suitability in both the East and West exists when 0.17 or moresuitably sized snags occur per 0.4 ha (1.0 acre). Habitats with no suitablysized snags provide no suitability. These snag sizes represent the minimumdbh for a useable snag. It is assumed that optimum conditions occur when theaverage dbh of all snags that meet the minimum size requirement is equal tothe average dbh of snags actualTy selec.ted by pileated woodpeck.ers for nestsites (see Conner 1979b). In the East, it is assumed that optimum conditionsoccur when the average dbh of all snags greater than 38 cm (15 inches) dbh is54 cm (21 inches). In the West, optimum habitats exist when the average dbhof all snags greater than 51 cm (20 inches) is 76 cm (30 inches). Habitats inthe East or West with an average snag diameter equal to the minimum suitablesize will provide one-half of optimum habitat suitability.Overall habitat suitability for the pilaated woodpecker is assumed to belimited by either the density and maturity of the forest or the abundance of ,~snags.ModelRelationshipsSuitabilty Index (SI) graphs for habitat variables. Thistains suitability index graphs that illustrate the habitatdescribed in the previous section.section conrelationshipsCoverszasEF,DF,EFW,DFWVariablePercent treecanopy closure.8o 25 50"75 10~

EF, OF.EFW,OFWNumber of trees> 51 cm (20 i~ches)dbh/0.4 ha (1.0 acre).1. 0-+----'--'---'--'--+)(~ 0.8c-~-0.6....~ 0.4~....:::IVl 0.2o 10 20 30 +EF,OF,EFW,OFWV, Number of tree stumps> 0.3 m (1.0 ft) inheight and> 18 cm(7 inches) diameterand/or logs> 18 cm(7 inches) diameter/0.4 ha (1.0 acre).1.0+- ---1. ;-)(~ 0.8c->,-0.6~:0fO0.4~~ 0.2o 5 10 +EF,OF,EFW,OFWv..Number of snags> 38 cm (15 inches)dbh/0.4 ha (1.0 acre).1. 0+----'---"---.........---+)(QJ 0.8"0-c~ 0.6:0 0.4fO~~ 0.2o .05 . 10 . 15 .20 +9

EF,DF,EFW ,DFWAverage dbh of snags> 38 cm (15 inches)dbh.1.0x 0.8QJ"0c::....~ 0.6~.r-r-.r-..Q10~0r-=:;,VI0.40.238154618532161 + cm24 + inEF,DF,EFW ,DFWNumber of snags> 51 cm (20 inches)dbh/0.4 ha (1.0 acre).x1.0~ 0.8c:....~ 0.6.r-r-.r-..Q10 0.4~0r-=:;,VI0.2o .05 .10 . 15 .20 +EF,DF, V 7 Average dbh of snags 1.0EPW,DFW > 51 cm (20 inches)dbh.xQJ"0 0.8.... c:~ 0.6.r-r-:0 0.4to~.,...a 0.251 63 76 + em20 25 30 + in10/~

Equations. In order to determine the life requisite value for the pileatedwoodpecker. the 51 values for appropriate variables must be combined throughthe use of equations. A discussion and explanation of the assumed relationshipbetween variables was included under Model Description. and the specificequations in this model were chosen to mimic these perceived biological relationshipsas closely as possible. The suggested equations for obtaining thefood/ cover/reproduction value are presented below.Life requisiteEastern portion of range:Food/cover/reproductionCover typeEF.DF,EFW.DFWEguationLower of (V 1x V z x V J)I/ 2or (V~x V s)I/2Western portion of range:Food/cover/reproductionEF,DF.EFW,DFW .Lower of (V 1x V z x V J)I/ 2or (V, x V,)1/2HSI determination. The HSI for the pileated woodpecker is equal to thelife requisite value for food/cover/reproduction.Application of the ModelDefinitions of variables and· suggested field measurement techniques (Hayset al. 1981) are provided in Figure 2. Note that V~ and VI are to be measuredonly in the eastern portion of the range of the pileated woodpecker. and V,and V, in the western portion of the range.Variable (definition)Percent tree canopyclosure [the percentof the ground surfacethat is shaded by avertical projection ofthe canopies of allwoody vegetation tallerthan 5.0 m (16.5 ft)J.Cover typesEF,DF,EFW,DFWSugoested technigueLine interceptFigure 2.Definitions of variables and suggested measurement techniques.11

Variable (definition) Cover types Suggested technigue ~Va Number of trees > 51 cm EF,OF,EFW, Quadratdbh/0.4 ha (20 inchesOFWdbh/l.0 acre) [actualor estimated number oftrees that are greaterthan 51 em (20 inches)diameter at breast height(1.4 m (4.5 ft) per 0.4 ha(~.O acre)].V J Number of tree stumps EF,DF.EFW, Quadrat> 0.3 m (1.0 ft) in OFWheight and> 18 cm(7 inches) diameterand/or logs> 18 cm(7 inches) diameter/0.4 ha (1.0 acre)[the actual or estimatednumber of treestumps greater than 0.3 m(1.0 ft) in height andgreater than 18 em(7 inches) in diameter,and/or logs greaterthan 18 em (7 inches)in diameter present peracre. Log diametershould be measured atthe largest point].V,. Number of snags > 38 em EF,DF,EFW, Quadrat(IS inches) dbh/0.4 haOFW(1.0 acre) [the numberof standing dead treesor partly dead trees,that are greater than38 em (15 inches) diameterat breast height(1.4 m/4.5 tt), andthat are at least 1.8 m(6 ft) tall, per 0.4 ha(1.0 acre). Trees inwhich at least 50% of thebranches have fallen, orare present but no longerbear foliage, are to beconsidered snags].Figure 2.(continued).12

Variable (definition)Average dbh of snags> 38 cm (15 inches) dbh[the average diameterof all snags that exceed38 cm (IS inches) diameterat breast height (1.4 m/4.5 ft)].Number of snags > 51 cm(20 inches) dbh/0.4 ha(1.0 acre) [the numberof standing dead treesor partly dead trees,that are greater than51 cm (20 inches) diameterat breast height(1.4 m/4.5 ft), and thatare at least 1.8 m (6 ft)tall, per 0.4 ha (1.0 acre).Trees in which at least50% of the branches havefallen, or are presentbut no longer bearfo1iQge, are to be consideredsnags].v, Average dbh of snags> 51 cm (20 inches)dbh [the averagediameter of all snagsthat exceed 51 cm(20 inches) diameterat breast height(1.4 m/4.5 ft)J.Cover typesEF,DF,EFW,DFWEF,DF,EFW,D~EF,DF,EFW,DFWSuggested technigueQuadrat; Biltmorestick or diametertapeQuadratQuadrat; Biltmorestick or diametertapeSOURCES OF OTHER MODELSFigure 2.(concluded).Conner and Adkisson (1976) have developed a discriminant function mod~lfor the pi1eated woodpecker that can be used to separate habitats that possiblyprovide nesting habitat from those that do not provide nesting habitat. Themodel assesses basal area, number of stems, and canopy height of trees.13

REFERENCESBeal, F. E. L. 1911. Food of the woodpeckers of the United States. U.S.Dept. Agric., Biol. Surv. Bull. 37:33-35.Bock, C. E., and L. W. Lepthien. 1975. A Christmas count analysis of woodpeckerabundance in the United States. Wilson Bull. 87(3):355-366.Bull, E. L. 1975. Habitat utilization of the pileated woodpecker. BlueMountains, Oregon. M.S. Thesis, Oregon State Univ., Corvallis. 58 pp.1981. How woodpeckers select and partition their habitat innortheastern Oregon. Ph.D. Diss., Univ. Idaho, Moscow. 99 pp.Personal communication (letter dated 20 October, 1982). U.S.Dept. Agric., For. Serv., Range and Wildl. Habitat Lab., La Grande, OR.Bull, E. L., and E. C. Meslow. 1977. Habitat requirements of the pileatedwoodpecker in northeastern Oregon. J. For. 75(6):335-337.Bull, E. L., A. D. Twombly, and T. G. Quigley. 1980. Perpetuating snags inmanaged conifer forests of the Blue Mountains, Oregon. Pages 325-336 inR. M. DeGraaf and N. G. Tilgham, compilers. Management of western forestsand grasslands for nongame birds. U.S. Dept. Agric., For. Servo Gen.Tech. Rep. INT-86. 535 pp.Conner, R. N. 1978. Snag management for cavity nesttng birds. Pages 120-128in R. M. DeGraaf, tech. coord. Management of southern forests for nongamebirds. U.S. Dept. Agric., For. Servo Gen. Tech. Rep. SE-14. 176 pp.1979a. Seasonal changes in woodpecker foraging methods:Strategies for winter survival. Pages 95-105 in J. G. Dickson, R. N.Conner, R. R. Fleet, J. C. Kroll, and J. A. Jackson, eds. The role ofinsectivorous birds in forest ecosystems. Academic Press, NY. 381 pp.. 1979b. Minimum standards and forest wildl He management.---~W~i~ld~l~.~S~oc. Bull. 7(4):293-296.. 1980. Foraging habitats of woodpeckers in southwestern--"""'V,-=-·r-g--:-i-n,-=-'a-. J. Field Ornitho 1. 51(2): 119-127.____~~~~. 1981. Seasonal changes in woodpecker foraging patterns. Auk98(3):562-570.Personal communication (letter dated 10 November, 1982).U.S. Dept. Agric., For. Serv., Southern For. Exp. Stn., Nacogdoches, TX.Conner, R. N., and C. S. Adkisson. 1976. Discriminant function analysis: Apossible aid in determining the impact of forest management on woodpeckernesting habitat. For. Sci. 22(2):122-127.14

Conner, R. N., R. G. Hooper, H. S. Crawford, and H. S. Mosby. 1975. Woodpeckernesting habitat in cut and uncut woodlands in Virginia. J. Wi1d1.Manage. 39(1):144-150.Conner, R. N., O. K. Miller, Jr., and C. S. Adkisson. 1976. Woodpeckerdependence on trees infected by fungal heart rots. Wilson Bull.88(4):575-581.Eva~s, K. E., and R. N. Conner.R. M. DeGraaf, tech. coord.forests for nongame birds.NC-S1. 268 pp.1979. Snag management. Pages 215-225 inManagement of north central and northeasternU.S. Dept. Agric., For. Servo Gen. Tech. Rep.Graber, J. W., R. R. Graber, and E. L. Kirk. 1977. Illinois 'birds: Picidae.Illinois Nat. Hist. Surv. Bio1. Notes 102:15-21.Hays, R. L., C. S. Summers, and W. Seitz. 1981. Estimating wildlife habitatvariables. U.S. Dept. Int., Fish Wild1.' Servo FWS/OBS-81/47. III pp.Kilnam. L. 1959. Behavior and methods of communication of pileated woodpeckers.Condor 61(6):377-387.1976. Winter foraging and associated behavior of pileatedwoodpeckers in Georgia and Florida. Auk 83(1):15-24.,1979. Courtship and the pair-bond of pileated woodpeckers.Auk 96(3):587-594.Mannan, R. W., E. C. Mes10w, and H. M. Wright. 1980. Use of snags by birdsin Douglas-fir forests, western Oregon. J. Wildl. Manage. 44(4):787-797.McClelland, B. R. 1979. The pileated woodpecker in forests of the northernRocky Mountains. Pages 283-299 in J. G. Dickson. R. N. Conner, R. R.Fleet, J. C. Kroll. and J. A. Jackson, eds. The role of insectivorousbirds in forest ecosystems. Academic Press, NY. 381 pp.Schardien, B. J., and J. A. Jackson. 1978. Extensive ground foraging bypileated woodpeckers in recently burned pine forests. Mississippi Kite8(1):7-9.Thomas, J. W.• R. G. Anderson, C. Maser. and E. L. Bull. 1979. Snags.Pages 60-77 in J. W. Thomas. ed. Wildlife habitat in managed forests--theBl ue Mounta ins of Oregon and Washi ngton. U. S. Dept. Agri C:., For. Serv.Agric. Handb. 553. 512 pp.U.S. Fish and Wildlife Service. 1981. Standards for the development ofhabitat suitability index models. 103 ESM. U.S. Dept. Int.• Fish Wildl.Serv.• Di V. Eco1. Serv. n. p.15

K&,rUftl _~.c.nIAII"'" ••'_~---· ..-.PAGE I FWS/OBS-82/10.39Habitat Suitability Index Models:Pi1eated Woodpecker1- ..__...--..-I. ltetl8ft 0...I, Apri 1 1983~~a~dL. SchroederHabitat Evaluatlon Procedures uroupWestern Energy and Land Use TeamU.S. Fish and Wildlife ServiceDrake Creekside Building One2627 Redwing RoadFort Collins. CO 80526Western Energy and Land Use TeamDivision of Biological ServicesResearch and DevelopmentFish and Wildlife ServiceWashinaton. DC 20240L ..._ ... 0"."1&.'"'' R.IIl. ~-10. ~Iea/T"./w." Una, N..(Q(CO)Iu. TJIIO ., Rooon .. P.nOCll eo...re ..IA review and synthesis of existing information was used to develop a habitatmodel for the pi1eated woodpecker (DryocopuS pi1eatus). The model is scaledto produce an index of habitat suitability between 0 (unsuitable habitat) and1 (optimally suitable habitat) for areas of the continental United States.Habitat suitability indexes are designed for use' with Habitat EvaluationProcedures previously developed by the U.S. Fish and Wildlife Service.Mathematical models, Wildlife, Birds, Habitability.Pi1eated woodpeckerDryocopuS pi1eatusHabitat Suitability Indexes (HSI)c. ceSATI Fi.llI/GtOw.lL .....al•••lory St.'.",.n,Release unlimited. 111. S~"ry CI••• (Til,. 1t._ItIUNCLASSIFIED, 21. No. 01 PIli"i 15~. P'lce. uS GO....ER...loIENT PRINTING OFFICE 1983-

..National Wetlands ResearchCenter Library//11//1//11//1///1/1//11//1/1///11/284096:- ..._--r- - - ­L...,_I......_-,I : ,---III~ "1»q_IIII. 00_ 01 8ooIoQca&sen.oce•. VI'1IIl6Il9-. DCx UsI.,n W'IY _ ~ UN T_~o.n.WY• _-.. CoeaaM (_,..ern. T.....s.-II. LA• V.••I.,,, ( ....a' _ ~ UN T.....fl. COIIIII&. CO• LOCII_ 01 Reg-.. OIlIC••. ..,.-REGION 1Regiorutl Directoru.s. Fish and Wildlife ServiceUoyd Five Hundred Building. Sui ie 16LJ2500 N.E. Muhnumah StreetPordlAnd. Oregon q72J2REGION 2Regiunal Directoru.s. Fiih and Wildlife ServiceP.O. Bu), 1306Albuquerque. New Muico ~71 OJREGION 3Rcgional Directoru.s. Fish and Wildlife ServiceFederal Buildini:. FOri SnellingTwin Cilies, MinneSLlliI 551 I IREGION 4Regional Directoru.s. Fish and Wildlife ServkeRi~hard B. RU55ClI Building7S Spring SUCCi. S.W.Allanta, Geor~a 30303REGION 5Regional DirectorU.S. Fish and WildlifeServiceOne Galcway CenterNewlon Corner, Mas~l:husells 0215~REGION 6Regional DirectorU.S. Fish lind Wildlife ServiceP.O. Box 254~6Denver Federal CcnlcrDenver. Colurlido ~O~25REGION 7Regional DucclUrU.s. Fish lAnd WildlifcService101 I 1::. Tudor RuadAn~hllrage, Alil5k:l 'JC)~OJ

DEPARTMENT OF THE INTERIORu.s. FISH AND WILDLIFE SERVICEM the Nation's principal conservation aaeney, the Department of the Interior has responaioilityfor most of our .nationally owned public landa and natural resources. This includesfosterin. the wiust use of our land and water rnources, protectina our fish and wildlife,preun/ina th.environmental and cultural values of our national parks and historical places,ana providi"l for the enjoyment of life throuah outdoor recreation. The Department as'usses our en.rlY and min.ral resources and works to assure that their development is inthe blst Inter.ats of all our people. The Department also has a major responsibility forAm.rican lnaian res.rvation communities and for people who live in island territories underU.s. edmlnlstration.