April 20 2011

12:00 LSB 2320

Rulon Clark
Dept of Biology, San Diego State University

Predator-prey interactions between Northern Pacific Rattlesnakes (Crotalus oreganus) and California Ground Squirrels (Spermophilus beecheyi): the response of predators


When encountering predators, prey often exhibit conspicuous antipredator displays that communicate their awareness of the predator and/or their ability to escape. Predators are thought to alter their hunting behavior in response to these signals; however, there is little empirical evidence on predator behavior in most predator-prey communication systems. This is likely due to the difficulty of documenting signaling interactions and predator behavior under natural conditions. Rattlesnakes are an ideal predator for studying naturally occurring predator-prey interactions due to their sedentary ambush hunting style. We use a combination of radio telemetry and fixed videography to evaluate the responses of northern Pacific rattlesnakes to tail-flagging displays from California ground squirrels under natural conditions. Preliminary results from natural observations suggest that rattlesnakes rarely exhibit overt responses during the displays, but are more likely to abandon their ambush position after receiving intense, prolonged displays. However, after leaving their ambush position, snakes often remained in the vicinity of interaction locales and continue to hunt squirrels. With our ongoing field observations and experiments we hope to make a comprehensive assessment of predator responses to antipredator displays from prey, which will potentially contribute much needed empirical insight to predator-prey communication theory.















































































































































































































































































































































































































































































































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