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This study compares the avian species diversity at two eastern Nebraska wetlands that differ in their relative isolation from an urban environment. Birds were surveyed by the point Count method twice weekly at each site during June of 1998. Diversity was measured using species richness and species evenness. The percentage of bird species observed that depend on wetlands for breeding was also compared.
Results suggest that both species richness and evenness, as determined by the Shannon-Wiener index, were higher at the wetland located in a network of other marsh areas and agricultural land than at the suburban wetland. Immigration of species may be facilitated by closer proximity to other natural areas in general. However, the proximity to other marshes had little effect on wetland breeding species, as the difference between relative percentage of wetland birds present was small. Differences between species richness and evenness at the two sites may also be attributed to vegetative structure and varying levels of local traffic.