INFLUENCE OF PREGNANCY ON THERMOREGULATION OF WATER SNAKES (NERODIA-RHOMBIFERA)

1. We compared preferred body temperatures (T(b)s) of gravid, nongravi d and postparturient diamondback water snakes (Nerodia rhombifera) in linear thigmothermal gradients. 2. Gravid females had a significantly higher mean preferred T-b (27.7 +/- 0.3 degrees C) than nongravid (24. 8 +/- O.8 degrees C), postparturient winter (22.3 +/- 2.2 degrees C) a nd postparturient summer (24.1 +/- 1.2 degrees C) snakes. 3. Gravid sn akes spent longer periods at higher temperatures and had no diel cycle in T-b, but nongravid and postparturient winter snakes had higher T-b in the scotophase than in the photophase. 4. The selected T(b)s of gr avid snakes varied less than that of nongravid and postparturient grou ps.