Pigmy Rattlesnakes Use Frog-Derived Chemical Cues to Select Foraging Sites

Abstract

We performed a field experiment to test the hypothesis that pigmy rattlesnakes select foraging locations based on the presence of prey odor. We established six pairs of parallel transects, each 25 m long; the experimental transect was sprayed with distilled water in which leopard frogs had been housed for 48 h, and the parallel control transect was sprayed only with distilled water. The transects were then censused for the presence of pigmy rattlesnakes at 24-h intervals for the next 96 h. More snakes were found along the experimental transects at all times, and significantly more (P = 0.019, binomial test) were found at 72 h after spraying. Our results indicate that prey odor is at least one of the factors involved in foraging site selection by these sit-and-wait predators.