Behavioural responses by hatchling racers (Coluber constrictor) from two geographically distinct populations to chemical stimuli from potential prey and predators

In experiments on responses to chemical food stimuli by previously unfed hatchlings from widely separated populations of the colubrid snake Coluber constrictor in the United States, strong responses were elicited by items important in the local diet. These differed between populations, suggesting that response has been adjusted to local diet by natural selection. Coluber constrictor priapus from South Carolina tongue-flicked at elevated rates to cues from lizards, snakes, and frogs, and bit only in response to a preferred lizard prey. They responded more strongly to the sympatric lizard Anolis carolinensis than to A. sagrei, an allopatric congener. Strong response to cues from the ophidiophagous snake Lampropeltis triangulum might reflect motivation for predator avoidance or for feeding, depending on relative snake sizes. Coluber constrictor mormon, for which insects and mammals are the most important foods, responded most strongly to stimuli from sympatric insects, mammals, and a lizard, as well as a bird.