Meeting Abstract
Urbanization can affect the behavior of free-living animals. We examined the effects of low-density urbanization on extra-pair mating in urban and rural populations of song sparrows (Melospiza melodia) in Montgomery County, VA. We genotyped 70 song sparrow nestlings from 27 nests, along with their social parents and all other captured adults at 15 microsatellite loci. We assigned genetic paternity using the program CERVUS, successfully assigning 38 of 70 nestlings (54%) to a father. Only one nestling was assigned to a male that was not the social father, confirming extra-pair paternity. However, 22 additional nestlings were tested against a genotyped social father, but not assigned to a genetic father, leaving the possibility of extra-pair siring by an unsampled male. The lack of successful assignment of nestlings to sampled social fathers suggests that up to 34% of nestlings may be the result of extra-pair mating, in line with other studies of extra-pair paternity in song sparrows. Preliminary results suggest that there are higher rates of extra-pair offspring and nests in rural areas, as compared to urban areas. However, due to a limited sample size of rural nests (N=3), we cannot yet draw definitive conclusions about the effects of urbanization on extra-pair mating. Future plans include increased sampling of rural nests, and the use of single nucleotide polymorphisms (SNPs) to increase power to detect extra-pair mating.
