Evol Ecol Res 7: 273-286 (2005)     Full PDF if your library subscribes.

Voles competing with mice: differentiating exploitative, interference and apparent competition using patch use theory

Kenneth A. Schmidt,* Robert Manson‡ and David Lewis§

Institute of Ecosystem Studies, Box AB, Millbrook, NY 12545, USA

Address all correspondence to Kenneth A. Schmidt, Department of Biological Sciences, Texas Tech University, MS 3131, Lubbock, TX 79409, USA.
e-mail: kenneth.schmidt@ttu.edu

ABSTRACT

We derived unique sets of predictions from patch use theory to differentiate apparent, exploitative and interference competition. Armed with these predictions, we used field enclosures to determine whether white-footed mice (Peromyscus leucopus) perceived meadow voles (Microtus pennsylvanicus) as apparent competitors. The enclosures were sited at forest-field ecotones. Within them, we manipulated vole density, food patch microhabitat (i.e. predation risk) and distance from the forest edge. We studied the effect of these variables on giving-up densities of white-footed mice. Giving-up densities increased in response to higher vole activity. Under higher vole activity, mice increased foraging costs associated with risky, open microhabitats. These results were consistent only with apparent competition. Thus shared predators may be contributing to the pattern of habitat selection between mice and voles along forest-field ecotones.

Keywords: apparent competition, competition, ecotone, giving-up density, habitat selection, interference, Microtus, patch use theory, Peromyscus.

DOWNLOAD A FREE, FULL PDF COPY
IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.

 

        © 2005 Kenneth A. Schmidt. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.

       Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.

       All copies of abstracts and articles must preserve their copyright notice without modification.