Effects of resource distribution, patch spacing, and preharvest information on foraging decisions of northern bobwhites
| Autor: | Stephan G. Kohlmann, Kenneth L. Risenhoover |
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| Rok vydání: | 1998 |
| Předmět: | |
| Zdroj: | Behavioral Ecology. 9:177-186 |
| ISSN: | 1465-7279 1045-2249 |
| Popis: | We investigated patch assessment by northern bobwhites (Colinus virginianus) in an experimental arena where the distribution of resources in patches, preharvest information about these patches, and spacing of patches varied. We found that preharvest information about patch quality and a bimodal distribution of patch rewards allowed birds to selectively exploit patches high in resources. In contrast, uniform distribution of patch qualities and lack of preharvest information caused birds to forage nonselectively among patches. Birds distinguished among patches of different quality when these patches were spaced 1 3 m apart, but failed to react to patch quality differences when patches were 0 or S m apart We also found a strong effect of the level of patch depletion on foraging decisions: as resources in die arena became scarce, birds increasingly foraged selectively in die most profitable patches. Foraging decisions of bobwhites are biased by die way they experience and memorize a spatially and temporally variable environment. The relative cost of this cognitive bias (i.e., lost opportunity) is nonlinearty related to die mean resource density in die environment and to die difference between this mean density and die resource density in die exploited patch. Cognitive bias should be considered when evaluating patch assessment capabilities of foragers in complex environments. |
| Databáze: | OpenAIRE |
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