Choosing among alternative refuges: Distances and directions |
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| Authors: | William E Cooper Jr Diogo S M Samia |
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| Affiliation: | 1. Department of Biology, Indiana University Purdue University Fort Wayne, Fort Wayne, IN, USA;2. Department of Ecology, Bioscience Institute, University of Sao Paulo, Sao Paulo, Brazil |
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| Abstract: | Many prey flee to refuges to escape from approaching predators, but little is known about how they select one among many refuges available. The problem of choice among alternative refuges has not been modeled previously, but a recent model that predicts flight initiation distance (FID = predator–prey distance when escape starts) for a prey fleeing to a refuge provides a basis for predicting which refuge should be chosen. Because fleeing is costly, prey should choose to flee to the refuge permitting the shortest FID. The model predicts that the more distant of two refuges can be favored if it is not too far and if the prey's trajectory to the farther refuge is more away from the predator than the direction to the nearer refuge. The difference in predicted FID between the farther and nearer refuges increases curvilinearly as the interpath angle for the farther refuge increases. The difference in predicted FID between the farther and nearer refuges increases linearly as the distance to the farther refuge increases. An isocline describing where nearer and farther refuges are equally favored shows a negative curvilinear relationship between interpath angle and prey distance to the farther refuge. In the region below the isocline, the farther refuge is favored, whereas above the isocline the prey should flee to the nearer refuge. |
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| Keywords: | antipredatory defenses escape behavior flight initiation distance interpath angle multiple refuges refuge selection |
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