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Use of selection indices to model the functional response of predators

Ecology

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Abstract

The functional response of a predator to changing prey density is an important determinant of stability of predatora??prey systems. We show how Manly's selection indices can be used to distinguish between hyperbolic and sigmoidal models of a predator functional response to primary prey density in the presence of alternative prey. Specifically, an inverse relationship between prey density and preference for that prey results in a hyperbolic functional response while a positive relationship can yield either a hyperbolic or sigmoidal functional response, depending on the form and relative magnitudes of the density-dependent preference model, attack rate, and handling time. As an example, we examine wolf (Canis lupus) functional response to moose (Alces alces) density in the presence of caribou (Rangifer tarandus). The use of selection indices to evaluate the form of the functional response has significant advantages over previous attempts to fit Holling's functional response curves to killing-rate data directly, including increased sensitivity, use of relatively easily collected data, and consideration of other explanatory factors (e.g., weather, seasons, productivity).

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Use of selection indices to model the functional response of predators
Series title:
Ecology
Volume
84
Issue:
6
Year Published:
2003
Language:
English
Contributing office(s):
National Wildlife Health Center
Description:
p. 1635-1639
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
1635
Last page:
1639
Number of Pages:
5