Authors: Jill M Mateo
Publish Date: 2007/06/20
Volume: 62, Issue: 1, Pages: 37-49
Abstract
Predator–prey relationships provide an excellent opportunity to study coevolved adaptations Decades of theoretical and empirical research have illuminated the various behavioral adaptations exhibited by prey animals to avoid detection and capture and recent work has begun to characterize physiological adaptations such as immune reactions metabolic changes and hormonal responses to predators or their cues A 2year study quantified the activity budgets and antipredator responses of adult Belding’s ground squirrels Spermophilus beldingi living in three different California habitats and likely experiencing different predation pressures At one of these sites which is visually closed and predators and escape burrows are difficult to see animals responding to alarm calls remain alert longer and show more exaggerated responses than adults living in two populations that likely experience less intense predation pressure They also spend more time alert and less time foraging than adults at the other two sites A 4year study using noninvasive fecal sampling of cortisol metabolites revealed that S beldingi living in the closed site also have lower corticoid levels than adults at the other two sites The lower corticoids likely reflect that predation risk at this closed site is predictable and might allow animals to mount large acute cortisol responses facilitating escape from predators and enhanced vigilance while also promoting glucose storage for the approaching hibernation Collectively these data demonstrate that local environments and perceived predation risk influence not only foraging vigilance and antipredator behaviors but adrenal functioning as well which may be especially important for obligate hibernators that face competing demands on glucose storage and mobilizationI thank Melanie Brooks Jared Bruck Jason Bruck Matthew Heintz Anne Janas Becca Kordas Ella Malamud Meredith Nelson Kara Nuss Caroline Pitt and Wendy Tidhar for assistance in the field Jocelyn Bryant for conducting the hormone assays and Sonia Cavigelli Warren Holmes Nancy Peters and anonymous reviewers for critical readings of the manuscript I also thank Dan Leger for providing some of the S beldingi alarmcall recordings used here These studies were approved by Cornell University 4/20/00 0032 the University of Chicago 11/26/02 71255 and University of California at Santa Barbara 3/30/00 400532 503532 and adhere to standards set forth by the US NIH for animal research This work was supported by the NIMH
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