Date of Graduation

Spring 2016


Master of Science in Biology



Committee Chair

Brian Greene


cottonmouths, Agkistrodon piscivorus, venom expelled, skinks, frogs, snake body temperature

Subject Categories



Pit vipers possess a sophisticated venom delivery system enabling them to efficiently disable prey. To avoid retaliatory countermeasures, pit vipers typically release envenomated prey which are then trailed and consumed after succumbing to venom effects. Successful retrieval of released prey should vary with venom resistance and trail ability of prey types. The effects of prey size and prey type (mice, lizards, and frogs) on foraging behavior and venom expenditure in a cohort of juvenile cottonmouths was examined. Venom expenditure did not vary significantly among prey sizes or prey types. However, lizard prey were held significantly more often than mice. The effect of snake body temperature on foraging response variables across a range of ecologically relevant temperatures (18°C-30°C) was also examined. Cottonmouths injected significantly less venom, and held prey significantly more often, at 18°C than at 25°C or 30°C. These results are consistent with a thermal constraint on envenomation performance at lower operant temperatures. Overall, these results suggest that cottonmouths modify foraging behavior to compensate for both venom resistance in ectothermic prey and decreased performance at lower temperatures.


© Kari Lynn Spivey

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