Abstract
Foraging decisions made by predators influence the way in which predation shapes the structure of prey communities. Alternative prey species co-occurring in a patch embedded in a matrix of many similar patches may interact through a shared mobile predator in 2 distinct ways. 1) The functional response by an individual predator foraging in the patch to one prey species may be affected by the density of a 2nd prey species in the patch (eg any time spent handling one prey reduces the time available for capturing other prey). 2) The presence of a 2nd prey species may alter the propensity of predators to agregate or remain in a given patch. This aggregative numerical response can in many circumstances generate -,- interactions (apparent competition) between prey species that otherwise would not interact. This is most likely if predators use a simple optimality criterion for prey selectivity within patches and the marginal-value theorem for deciding when to enter and leave patches. By contrast, if predators have suboptimal diets within patches but leave in accord with the marginal-value theorem, alternative prey may experience a +,- interaction; and, if predators use patches independently of prey availability, a +,+ interaction between alternative prey can occur.-from Authors
Original language | English |
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Pages (from-to) | 412-430 |
Number of pages | 19 |
Journal | American Naturalist |
Volume | 130 |
Issue number | 3 |
DOIs | |
State | Published - 1 Jan 1987 |
Externally published | Yes |
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics