title: Factors affecting temperature variation and habitat use in free-ranging diamondback terrapins.
abstract: Measuring the thermal conditions of aquatic reptiles with temperature dataloggers is a cost-effective way to study their behavior and habitat use. Temperature dataloggers are a particularly useful and informative approach to studying organisms such as the estuarine diamondback terrapin (Malaclemys terrapin) that inhabits a dynamic environment often inaccessible to researchers. We used carapace-mounted dataloggers to measure hourly carapace temperature (Tc) of free-ranging terrapins in South Carolina from October 2007 to 2008 to examine the effects of month, sex, creek site, and tide on Tc and to determine the effects of month, sex, and time of day on terrapin basking frequency. Simultaneous measurements of environmental temperatures (Te; shallow mud, deep mud, water) allowed us to make inferences about terrapin microhabitat use. Terrapin Tc differed significantly among months and creek and between sexes. Terrapin microhabitat use also varied monthly, with shallow mud temperature being the best predictor of Tc November-March and water temperature being the best predictor of Tc April-October. Terrapins basked most frequently in spring and fall and males basked more frequently than females. Our study contributes to a fuller understanding of terrapin thermal biology and provides support for using dataloggers to investigate behavior and habitat use of aquatic ectotherms inhabiting dynamic environments.
authors.affiliation: Department of Biology, Davidson College, Davidson, NC 28035, USA.
authors.forename: C D
authors.initials: CD
authors.lastname: Akins
authors.affiliation: Department of Biology, Davidson College, Davidson, NC 28035, USA.
authors.forename: C D
authors.initials: CD
authors.lastname: Ruder
authors.affiliation: Department of Forestry, University of Kentucky, Lexington, KY 40546, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Price
authors.affiliation: Department of Biology, Davidson College, Davidson, NC 28035, USA. Electronic address: leharden@davidson.edu.
authors.forename: L A
authors.initials: LA
authors.lastname: Harden
authors.affiliation: Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Gibbons
authors.affiliation: Department of Biology, Davidson College, Davidson, NC 28035, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Dorcas
mesh_terms: D000818:Animals; D001833:Body Temperature Regulation; D017753:Ecosystem; D005260:Female; D008297:Male; D012621:Seasons; D012737:Sex Factors; D014426:Turtles / Q000502:physiology*
keywords: Datalogger; Diamondback terrapin; Estuarine; Habitat use; Semi-aquatic turtle; Temperature