Nebeker, A.V. and R.B. Bury. 2000. Temperature selection by hatchling and yearling Florida red-bellied turtles (Pseudemys nelsoni) in thermal gradients. Journal of Herpetology 34(3)465-469.
We tested hatchling and yearling Florida red-bellied turtles (Pseudemys nelsoni) in laboratory thermal gradient chambers to determine if they would prefer particular temperatures. Most 1995 hatchlings selected the highest temperature zone of 27EC (Test 1) and 30EC (Test 2) in the gradient. Yearlings (1995 turtles one year later) had more turtles in the highest temperature zone of 33EC. A second group of hatchlings (1996) a year later were tested in the square 6-channeled box used for the above tests, and a round 12-channeled (6 duplicate temperatures) chamber. Significantly higher numbers of turtles exposed in the square chamber selected 27EC and the highest temperature of 30EC, a response similar to the 1995 hatchlings. Turtles in the round chamber also had significantly higher numbers at 30EC, but most avoided the 33 degree water temperature. There were no significant differences in the preferred temperatures between the 1995 and 1996 turtles. During control tests when the gradient channels in the square and round chambers were all at 18EC (acclimation temperature), there was random distribution of animals. Clearly, young Pseudemys nelsoni select relatively high temperatures in laboratory gradients and behaviorly thermoregulate.