Neil C. Dazet

Date of Graduation

Spring 2010

Degree

Master of Natural and Applied Science in Biology

Department

Biology

Committee Chair

Don Moll

Abstract

The chemical secretions from the Rathke's glands of common musk turtles have a variety of proposed functions including predator deterrence and attraction, but experimental studies testing these hypotheses are lacking. This study used laboratory and field experiments to test whether musk secretions had attraction or repellent effects on two natural predators, the cottonmouth (Agkistrodon piscivorus), and the common snapping turtle (Chelydra serpentina). In a laboratory experiment, I examined latency to feed and consumption times for cottonmouths offered musk-treated minnows and control minnows. In a field study, I investigated the ratio of snapping turtles appearing in traps with and without musk-treated bait. The latency to feed times for cottonmouths offered musk-treated minnows were not significantly different from those offered control minnows. However, prey consumption times for cottonmouths feeding on musk-treated minnows were significantly greater than those feeding on control minnows. These results suggest that the musk secretions may lengthen the time of a predation sequence, possibly allowing the turtle more time to escape from the predator. The number of snapping turtles appearing in traps with musk-treated bait was significantly greater than the number of snapping turtles in traps without musk-treated bait. These results support the predator attraction hypothesis, where the signal may attract additional predators that interfere with a predation event, providing an opportunity for the prey to escape.

Keywords

predator-prey interactions, common musk turtle, Sternotherus odoratus, Rathke's glands, predator attraction, predatory sequence

Subject Categories

Biology

Copyright

© Neil C. Dazet

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