Jon Atwood, PhD
Department of Environmental Studies
Habitat fragmentation and loss are primary threats to biodiversity. However, little is known about how residential development affects ecosystems, avian populations or individual species. Quaking aspen (Populus tremuloides), a species in decline, covers only 1% of the forested landscape in the Rocky Mountains but is nevertheless an important habitat for avian biodiversity. I studies the effects of low- and medium-density housing (<2 houses/ ha and 2-5 houses/ ha respectively), termed residential development, on bird communities and species using aspen habitat during the breeding season. Overall, residential development affected bird species indices (species abundance, species richness and species diversity) at fine scales (250m-500m spatial extents). These effects were best explained by multiple regression models containing habitat and landscape variables from multiple spatial scales. Based on species indices results, patch size and percent aspen in the landscape were most influential to bird habitat selection. However, analysis indicated that residential development had direct effects on individual species abundances. This study's most important contribution to conservation efforts was the identification of scales relevant to land managers and residential development. These results suggest that future conservation efforts should focus on both private and public lands.