Foraging mode switching : the importance of prey distribution and foraging currency
Abstract
Foraging methods are highly variable, but can be grouped into two modes: searching and ambush. While research has focused on the functioning of each mode, the question of how animals choose which to use has been largely neglected. Here we consider a forager that exploits prey that are patchily distributed in space and time. This forager can either sit and wait for prey to appear or search for prey, which is more likely to result in encounters with prey but costs more energy and/or exposes the forager to greater predation risk. The currency that natural selection appears to have optimized will be determined by the additional costs of searching and whether there is a risk of starvation. We therefore compare the predictions of models based on currencies that consider only energy and predation risk to state-dependent models in which energy reserves are used to trade off predation rate, starvation rate and investment in growth. The choice of currency qualitatively affects how mode should change when prey abundance and prey patchiness increase. We show how differing prey distributions can explain variation in effects of experimentally increasing prey abundance. Our work has several implications for the study of foraging mode, population dynamics and the methods used to assess population size.
Citation
Higginson , A D & Ruxton , G D 2015 , ' Foraging mode switching : the importance of prey distribution and foraging currency ' , Animal Behaviour , vol. 105 , pp. 121-137 . https://doi.org/10.1016/j.anbehav.2015.04.014
Publication
Animal Behaviour
Status
Peer reviewed
ISSN
0003-3472Type
Journal article
Rights
© 2015 The Authors. Published on behalf of The Association for the Study of Animal Behaviour by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Description
A.D.H. was supported by the European Research Council (Advanced Grant 250209 to Alasdair Houston), a College for Life Sciences Fellowship at the Wissenschaftskolleg zu Berlin, and a NERC Independent Research FellowshipNE/L011921/1.Collections
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