Thirst and drinking in North American watersnakes (Nerodia spp.)

Abstract

We quantified drinking behavior in three species of North American watersnakes: Nerodia clarkii, which is a marine or brackish water amphibious species, and Nerodia fasciata and Nerodia taxispilota, both freshwater amphibious species. All three species have relatively small and similar thresholds of dehydration (TH, approximately -4% loss of body mass) that elicit thirst and drinking of fresh water. These species have higher thirst sensitivity than several species of hydrophiine and laticaudine sea snakes, which are characterized by much lower TH (greater dehydration, -9% to