Species richness, abundance, and genetic variability often decrease in bird populations when their habitats are subjected to anthropogenic activity. Regular and early monitoring of genetic diversity can give researchers and wildlife managers insight into the genetic health of populations so that action can be taken before inbreeding, loss of disease resistance, and population declines occur. We measured genetic diversity in populations of avian species that are increasingly exposed to anthropogenic changes. We analyzed samples from 89 individual birds from three locations in Gwinnett County, Georgia. Samples were collected from a total of seven species, four migratory [myrtle warbler (Setophaga coronata), American robin (Turdus migratorius), American goldfinch (Spinus tristis), and field sparrow (Spizella pusilla)] and three non-migratory [northern cardinal (Cardinalis cardinalis), brown-headed nuthatch (Sitta pusilla), and white-breasted nuthatch (S. carolinensis)]. DNA sequences of the mitochondrial gene cytochrome c oxidase subunit 1 (COI) were compared to determine intraspecific genetic diversity. We found that genetic diversity varied among the seven species studied. Overall, nucleotide and haplotype diversity in COI was higher for non-migrants compared to migratory species. Comparisons of genetic diversity among study sites found that the least urbanized of the three locations had greater genetic diversity than the other two locations. As human development continues to eliminate natural areas, additional genetic monitoring is recommended for Gwinnett County and other rapidly developing urban areas.
