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GRAPTEMYS GIBBONSI (Pascagoula Map Turtle). BASKINGAND PARASITE REMOVAL. The primary physiological roleof basking by turtles is presumed to be for thermoregulation (Boyer1965. Ecology 46:99–118), to increase metabolism and digestionrates (Moll and Legler 1971. Bull. Los Angeles Co. Mus. Nat.Hist. Sci. 11:1–102). However, additional basking hypotheses andsecondary roles of basking have been proposed including to aid invitamin D synthesis (Pritchard and Greenhood 1968. Int. TurtleTortoise Soc. J. 2:20–25, 34) and to rid turtles of ectoparasites(Cagle 1950. Ecol. Monogr. 20:31–54; Neill and Allen 1954. Ecology35:581–584; Vogt 1979. Auk 96:608–609). Here we provideevidence to support the hypothesis that basking aids turtles in parasiteremoval as a secondary role and (to our knowledge) the firstdocumented observation of basking-induced release of a parasitefrom a turtle while basking.On 17 May 2007 (1125 h), WS and DS observed a large femaleGraptemys gibbonsi (>20 cm, ca. 1500 g) emerge on a large logsizedsnag to bask (Leaf River, Forrest Co., Mississippi). The femaleemerged facing the observers and a large leech (Placobdellasp.) was noted on the anterior left pleural scute of the carapace. Atthis time, the leech was in an elongated position. After 10 minutes(1135 h), the leech was observed shortening into a ball-shapedposture; it is presumed that this posture was used by the leech forwater conservation. After 35 minutes of basking (1200 h), the turtlebegan to exhibit ‘gaping’ behavior while basking, evidently reachinga high internal body temperature. Soon after at 1212 h (47minutes after turtle emergence), the leech terminated the ball-shapeand moved slowly toward the left margin of the turtle near thebridge of the shell. At 1214 h (after 49 minutes), the leech removedone end of its body from the margin of the turtle and beganto ‘search’ below toward the log, while the other end was stillattached at the margin of the carapace. The leech attached the freeend of its body to the log and the attached end on the carapacefollowed, thus removing itself from the turtle. At 1215 h (after 50minutes), the leech reentered the water at the edge of the baskinglog.During this time, a G. flavimaculata female was basking on thesame log as the female G. gibbonsi. The surface temperature ofthe G. flavimaculata female was being monitored via a carapacemounted temperature sensitive transmitter (AVM Instruments). Thecarapace temperature of the G. flavimaculata female during thisobservation of the G. gibbonsi female was 40–42°C. Therefore,the carapace temperature of the G. gibbonsi female was probablycomparable to the carapace temperature of the G. flavimaculata,and thus, likely hot enough to induce the leech to voluntarily releaseitself from its host organism. To our knowledge, this is thefirst documented observation of voluntary parasite release duringbasking, and supports the secondary hypothesis of basking as ameans for parasite removal.Submitted by WILL SELMAN, DUSTIN STRONG, andCARL QUALLS, Department of Biological Sciences, Box 5018,University of Southern Mississippi, Hattiesburg, Mississippi39401, USA (e-mail: will.selman@usm.edu).GRAPTEMYS GIBBONSI (Pascagoula Map Turtle). INTER-SPECIFIC COMPETITION FOR BASKING SITES.Graptemys gibbonsi is a highly aquatic freshwater turtle that inhabitsthe Pearl and Pascagoula rivers and tributaries of Mississippiand Louisiana, USA (Ernst et al. 1994. Turtles of the UnitedStates and Canada. Smithsonian Institute Press, Washington, D.C.578 pp.). Very little is known concerning the life history and ecologyof G. gibbonsi, and previous research within the Pearl andPascagoula Rivers has focused predominantly on the two federallythreatened species (G. flavimaculata within the PascagoulaRiver and G. oculifera within the Pearl River) that occur sympatricallywith G. gibbonsi. These observations of G. gibbonsi baskingbehavior were made within the Pascagoula River system.On 14 June 2006 (1200 h), on the Chickasawhay River (GreeneCounty, Mississippi), WS observed a male G. gibbonsi emergefrom the water and position himself above the water’s surface ona low-angled, branch-sized snag. After several minutes, a slightlylarger Apalone sp. approached and climbed onto the submergedportion of the same snag. The Apalone remained partially abovethe surface of the water, but was apparently not in an optimal baskinglocation; it then extended its head forward and proceeded tonudge or bite (unknown due to the observation distance) the posteriorof the male G. gibbonsi. The G. gibbonsi reacted by climbingup the snag. This sequence occurred again until the G. gibbonsimoved far enough up the snag to allow the Apalone to emergefully from the water, presumably achieving a more optimal baskingsite.On 11 April 2007 (1250 h), WS observed a male G. gibbonsi,ca. 9 cm in carapace length, climb vertically 19.5 cm to get to adesired basking location on a low-angled snag (Leaf River, ForrestCounty, Mississippi). No other turtles occupied the log at this time.This chosen basking location was 1.5–1.8 m from the lowest angleat the air/water interface where most turtles would emerge ontothe snag. It could have chosen this “easier” location to emerge andonly climb a 10–15° angle rather than the chosen vertical climb. Itis unclear why the G. gibbonsi male chose this more difficult routeto get to a desired basking location. However, it is possible that hetook this route to avoid larger turtles that may emerge to baskfrom the lower angle at the air/water interface.Submitted by WILL SELMAN and CARL QUALLS, Departmentof Biological Sciences, Box 5018, University of SouthernMississippi, Hattiesburg, Mississippi 39401, USA (e-mail:will.selman@usm.edu).GRAPTEMYS GIBBONSI (Pascagoula Map Turtle). INTERAC-TIONS WITH DUCKS. Graptemys gibbonsi is an aquatic turtlethat inhabits the Pearl and Pascagoula rivers and tributaries ofMississippi and Louisiana, USA (Ernst et al. 1994. Turtles of theUnited States and Canada. Smithsonian Institute Press, Washington,D.C. 578 pp.). Very little is known about the life history of G.gibbonsi following its description as a species in 1992 (Lovichand McCoy 1992. Ann. Carnegie Mus. 61:293–315). Observationswere made on two occasions of interactions between adult femaleG. gibbonsi and Wood Ducks (Aix sponsa).On 11 May 2006 (1500 h), on Oakohay Creek (CovingtonCounty, Mississippi), WS observed a basking adult female G.gibbonsi on a horizontal log-sized snag, along with a pair of WoodDucks. The two Wood Ducks were startled by the approachingboat, but the female G. gibbonsi was not startled off the log whenthey flew away. However, the turtle vacated the log ca. 30 seconds216 Herpetological Review 39(2), 2008