Thesis Title

Predatory Strike Behaviors Of The Western Cottonmouth, Agkistrodon Piscivorus Leucostoma

Date of Graduation

Summer 2004


Master of Science in Biology



Committee Chair

Brian Greene


Pitvipers typically release and trail envenomated prey in a stereotypic behavior pattern known as strike-induced chemosensory searching, thus avoiding retaliatory injury while prey are immobilized by venom. However, retaining prey can increase foraging success on prey that are difficult to trail or are not rapidly immobilized by venom. In a laboratory study, I evaluated the effect of prey size and prey type on foraging techniques in the cottonmouth, Agkistrodon piscivorus, which feeds indiscriminately on an array of small vertebrates, including lizards, snakes, fish, frogs, rodents, and birds. Prey size had no significant effect on the snakes' tendency to hold or release laboratory mice of different size classes. An additional experiment tested to see if prey capture behavior(s) varied among prey types that differ in immobilization time and trailing potential. Each snake was presented with each of three different prey types: Ranid frogs, Rana ssp, lab mouse, Mus musculus, and domestic chicken, Gallus domesticus. Prey type had no significant effect on the snakes' release behavior. Snakes tended to release all prey. Mice traveled a significantly greater distance after envenomation than the other two prey types. However, all prey types were rapidly immobilized and relocated, suggesting that failure to hold prey should not diminish foraging success.


Agkistrodon piscivorus, cottonmouth, snake foraging, pitviper, foraging behavior

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© William M. Ray