Browsing Biology by Author "Damm, Jason Philip"
Bat Species Diversity at an Urban-Rural Interface: Dominance by One Species in an Urban AreaDamm, Jason Philip (2012-01-13)The growth of urban areas is known to affect different species of wildlife in varying ways. Many organisms have exhibited declines in abundance due to habitat loss, while overall species diversity decreases. Bats can serve as reliable indicators of habitat quality and level of anthropogenic disturbance. To investigate urbanization impacts on a Midwestern bat community, I analyzed nine years of mist-net captures from a study area on the edge of Indianapolis, Indiana, where the percentage of urbanized ground cover ranged from zero to 26%, within 1.3-km of a net site. I used Pearson correlation statistics to examine the effect of urban ground cover on each species’ abundance, and the Shannon-Wiener Diversity Index was used to quantify species diversity at the study area. To test the effect of urbanization on diversity, linear mixed models were constructed using percentage of urban ground cover and year. A total of 10 species were captured over nine years, seven of them annually. The big brown bat (Eptesicus fuscus) was the dominant species at all urbanized sites and at five of six rural sites. Most species were more common at rural sites than at urbanized sites. Urbanization was significantly and negatively related to bat species diversity, although one species, the northern myotis (Myotis septentrionalis), showed a significant positive correlation with urban ground cover. Two bat species, the eastern pipistrelle (Perimyotis subflavus) and the little brown myotis (Myotis lucifugus) both displayed significant negative correlations with the percentage of urban ground cover. The Indiana myotis (Myotis sodalis) had a marginal negative correlation, but not significant.