Frequency of Tail Breakage of the Northern Watersnake, Nerodia sipedon sipedon

I noted the frequency of broken tails of Northern Watersnakes, Nerodia sipedon sipedon, in the Beaver Archipelago of Northeastern Lake Michigan. Overall, 10% (22 of 220) of captured snakes had broken tails. This value is similar to published values for closely related snakes but is smaller than those reported for another Nerodia sipedon sipedon population. Unlike some previously published studies, the frequency of injured tails was not greater for females or lesser for first-year snakes. The mechanism behind the injury frequency observed here and the reason for differences between this and other studies are unknown.