Niche breadth and vertebrate sensitivity to habitat modification: signals from multiple taxa across replicated landscapes

Wildlife species differ in their resistance to landscape modifications including habitat loss and fragmentation. We hypothesized that niche breadth is positively related to both (1) overall species occurrence and (2) species response to landscape modification, because species with a wide range of diet and/or habitat preferences should be able to colonize and survive in more patches than specialized species. We tested the hypothesis using occurrence data from 65 species spanning multiple taxonomic groups (birds, small mammals, bats, and aquatic turtles) collected in thirty-five 23km(2) landscapes in the Midwestern United States that varied in degree of modification. Niche breadth for each species was obtained from a combination of sources on habitat and diet requirements. We fit models for occurrence and response to modification as a function of niche breadth while accounting for imperfect detection and phylogenetic relatedness among species. As predicted, niche breadth was positively related to occurrence for all taxonomic groups. Response to landscape modification was positively related to niche breadth for birds, but there was no effect for the other taxonomic groups. Neither imperfect detection nor phylogeny affected relationships qualitatively. The lack of an effect of niche breadth on response to modification may be due to a long history of human land-use in the study region, resulting in assemblages in which all extant species have at least some resistance to agricultural disturbance.