Ambush Site Selection by Eastern Black-tailed Rattlesnakes (Crotalus ornatus) in the Northern Chihua

Emerson, James D. jdemerson@miners.utep.edu

DeSantis, Dominic

Johnson, Jerry

Department of Biological Sciences University of Texas at El Paso El Paso, Texas, USA

As organisms move throughout their environments, chemical signatures are left behind which are used by other species to mediate interspecific interactions. Most studies examining how these signatures influence behavior involve the use of predator chemical signatures by prey animals. However, predators often use these signatures to source information about potential prey as well. Crotalus ornatus is an ambush predator in the Chihuahuan Desert, selecting ambush sites where it is likely to encounter prey and remaining immobile for long periods of time. I am investigating the innate ambush behavior of captive-reared C. ornatus. With no prior hunting experience, it is expected that these ambush predators will discriminate among prey chemical cues for ambush site selection. Chemical cues will be presented as aqueous extracts from the integument of potential prey items, including an invertebrate, amphibian, and multiple lizard and mammal cues. Neonates (N = 10) were obtained from gravid females (N = 4) that were part of an ongoing telemetry study at the Indio Mountains Research Station, located in Hudspeth County, Texas. Ambush site selection will be quantified based upon the lingual response and time spent oriented towards the prey cue coiled in stereotypical ambush position.