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Abstract |
Foragers can often show a broad range of strategies when searching for resources. The simplest foraging strategy is to search randomly within a habitat; however, foragers can often assess habitat quality over various spatial scales and use this information to keep themselves in, or direct themselves to, regions of high resource abundance or low predation risk. We investigated models that describe a population of consumers competing for a renewable resource that is distributed among discrete patches. Our aim was to identify what foraging strategy or strategies are expected to persist within a population, where strategies differ in the degree of habitat assessment (i.e. none, local, or global). We were interested in how the optimal strategies are dependent on the cost of assessment and habitat structure (i.e. the variation in renewal rates and predation risks among patches). The models showed that the simple random foraging strategy (i.e. make no habitat assessments) often persisted even when the cost of habitat assessment was low. Persistence could occur when habitat assessment and population dynamics generated an ideal free distribution because it could be exploited by the random foragers. Habitat assessment was more advantageous when consumers could not achieve ideal free distributions, which was more likely as patches became less productive. When productivity was low we sometimes observed the situation where different foraging strategies generated resource heterogeneities that promoted their coexistence, and this could occur even when all patches were intrinsically identical. |
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