Prey Species Influences Foraging Behaviors: Rattlesnake (Sistrurus miliarius) Predation on Little Brown Skinks (Scincella lateralis) and Giant Centipedes (Scolopendra viridis)

Abstract

Predators often evolve specialized behaviors to feed on dangerous prey. Centipedes are widely documented in the diet of viperid snakes, but the behaviors snakes use to consume these dangerous prey have been reported only anecdotally. To determine how prey type influenced snake foraging behaviors, we ran laboratory predation trials using 29 field-captured Pigmy Rattlesnakes (Sistrurus miliarius) with centipedes (Scolopendra viridis) and skinks (Scincella lateralis). In skink trials, Pigmy Rattlesnakes were significantly more likely to engage in sit-and-wait predation than in centipede trials where active pursuit of prey was frequent. Centipedes were struck by snakes in significantly more trials than skinks and the mean length of strikes directed at centipedes was significantly shorter than for the strikes directed at skinks. Strike latency was significantly lower for centipedes than for skinks. The location on the prey's body where the strike was directed did not differ in skink and centipede trials. The mean time from snake strike to last prey locomotion and to prey ingestion were both significantly longer for centipedes. Pigmy Rattlesnakes exhibited several behaviors in centipede trials, including head elevation when approaching prey, that were never observed in skink trials. Centipedes occasionally struck rattlesnakes, but the snakes did not have any apparent injuries. Pigmy Rattlesnakes displayed plasticity in foraging behaviors to effectively prey on centipedes. The implications of centipede consumption in vipers merits increased attention given its occurrence in dozens of species.