title: Density-dependent habitat selection in muskrats: a test of the ideal free distribution model.
abstract: Two predictions of the ideal free distribution model, a null hypothesis of habitat selection, were examined using free-ranging muskrats. We rejected the prediction that the proportion of the animals found in each of five habitats was independent of population size. Data on over-winter occupancy of muskrat dwellings tend also to refute the prediction of equal fitness reward among habitats. Habitat type and water-level had a profound effect on the suitability of a site for settlement. We concluded that the observed pattern of muskrat distribution followed more closely an ideal despotic distribution where some individuals benefited from a higher fitness because of resource monopolization. Current theories of density-dependent habitat selection, which assume an ideal free distribution, would not apply to muskrats and possibly to many other mammal species.
authors.affiliation: Department of Biology, University of Saskatchewan, S7N 0W0, Saskatoon, Saskatchewan, Canada.
authors.forename: F
authors.initials: F
authors.lastname: Messier
authors.affiliation: Department of Biology, University of Saskatchewan, S7N 0W0, Saskatoon, Saskatchewan, Canada.
authors.forename: J A
authors.initials: JA
authors.lastname: Virgl
authors.affiliation: Department of Biology, University of Saskatchewan, S7N 0W0, Saskatoon, Saskatchewan, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Marinelli
keywords: Habitat selection; Ideal free distribution; Muskrat; Ondatra zibethicus; Spatial distribution