title: Kangaroo rats change temperature when investigating rattlesnake predators.
abstract: Predator presence causes acute stress in mammals. A prey animal's stress response increases its chance of survival during life-threatening situations through adaptive changes in behavior and physiology. Some components of the physiological stress response can lead to changes in body surface temperatures. Body temperature changes in prey could provide information about prey state to predators that sense heat, such as pit vipers. We determined whether wild rodents undergo a stress-induced change in body surface temperature upon detecting and investigating rattlesnake predators. We staged encounters between free-ranging Merriam's kangaroo rats (Dipodomys merriami) and tethered Mojave rattlesnakes (Crotalus scutulatus) at baited feeding stations, and recorded interactions with a thermal-imaging camera. Kangaroo rats showed a significant change in maximum head temperature, snout temperature, and hind leg temperature during interactions with rattlesnakes. This supports the hypothesis that presence of a predator induces body temperature changes in prey animals. If changes in prey heat signature are detectable by heat-sensitive rattlesnakes, rattlesnakes could use this information to evaluate prey vigilance or arousal before striking; however, more detailed information on the sensory ecology of the pit organ under field conditions is needed to evaluate this possibility.
authors.affiliation: Department of Biology, San Diego State University, San Diego, CA, USA; Graduate Group in Ecology, Department of Neurobiology, Physiology, and Behavior, University of California, Davis, CA, USA. Electronic address: haschraft@ucdavis.edu.
authors.forename: Hannes A
authors.initials: HA
authors.lastname: Schraft
authors.affiliation: Department of Biology, San Diego State University, San Diego, CA, USA.
authors.forename: Rulon W
authors.initials: RW
authors.lastname: Clark
mesh_terms: D000818:Animals; D001831:Body Temperature / Q000502:physiology*; D017839:Crotalus; D004173:Dipodomys / Q000502:physiology*; D016014:Linear Models; D011235:Predatory Behavior / Q000502:physiology*; D013315:Stress, Psychological / Q000503:physiopathology*; D013817:Thermography
keywords: Infrared; Predator-induced stress; Predator-prey interaction; Stress-induced hyperthermia; Thermography