Behavioral Ecology Advance Access originally published online on February 19, 2008
Behavioral Ecology 2008 19(3):475-482; doi:10.1093/beheco/arn004
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When foraging and fear meet: using foraging hierarchies to inform assessments of landscapes of fear
Commonwealth Scientific and Industrial Research Organization (CSIRO) Sustainable Ecosystems, Davies Laboratory, PMB PO Aitkenvale, QLD 4814, Australia
Address correspondence to K.R. Searle. E-mail: krsearle{at}nrel.colostate.edu.
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Abstract |
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Anthropogenic environmental change is escalating in magnitude, rate, and extent, inducing cascading effects across trophic levels. Assessing the nature of these alterations to trophic interactions requires an understanding of how species' demography and behavior are altered by simultaneous, complex pressures. For predator–prey relationships, "landscapes of fear" have been used to measure the trade-off prey animals make between maximizing energy gain and minimizing risk of predation. However, hierarchical foraging theory predicts that the degree to which aggregations of resources are used will depend upon the context in which they occur, not merely on the predation risk associated with those patches. We develop a conceptual framework that synthesizes theories of foraging hierarchies and landscapes of fear to show how predation risk and resource variation may interact to influence foraging behavior. We show, experimentally, that northern brown bandicoots (Isoodon macrourus), do respond to the likely predation risk when making their foraging decisions; however, the food resources in the habitat surrounding the food patch also play a significant role in the degree to which food patches are used. This result has important implications for the accuracy of assessments of landscapes of fear and habitat use using observations of animal foraging behavior.
Key words: foraging hierarchies, giving-up densities, landscapes of fear, predation risk, predator–prey relationships, resource heterogeneity.
Received 23 May 2007; revised 30 November 2007; accepted 6 December 2007.