Nestedness analysis and conservation planning: the importance of place, environment, and life history across taxonomic groups

We used nested subsets analysis to examine distribution patterns of birds and butterflies in the same set of 83 locations in canyons of three mountain ranges in the Great Basin of western North America. We tested whether the same environmental variables influenced nestedness among taxonomic groups and among mountain ranges within taxonomic groups. We also examined whether nestedness of birds and butterflies appeared to be sensitive to human use of riparian areas in the ecoregion. Site area and topography did not appear to differ in their influence on nestedness of birds. By contrast, area and topography differed in how strongly they affected nestedness of butterflies, but their respective influence varied among mountain ranges. Riparian dependence had little discernible effect on nested distribution patterns of either taxonomic group. Because processes influencing distribution patterns can differ among taxonomic groups, and the relative importance of those processes may vary spatially even within a taxonomic group, we urge restraint in using birds and butterflies as surrogates of other taxa for conservation planning.