The Grinnellian niche of the wood thrush.

Results suggest that the limits of the breeding range of Catharus mustelina and its relative abundance within its range are not highly related to the presence of ecologically similar species. These parameters are better accounted for by variables such as species-specific nesting and foraging requirements, which in turn covary with the vegetation structure of the eastern deciduous forest. Studies of single-species geographical ecology should precede studies of assemblages. The Grinnellian model is more likely than the Hutchinsonian model to provide sound information on factors regulating the distribution and abundance of animals.-from Authors