Genetic effects of a population bottleneck on a restored deer herd in a national military park

Temporary reductions in population density (i.e., bottlenecks) can lead to reduced levels of genetic variation and fitness. Chickamauga Battlefield Na tional Military Park, Georgia, was stocked with 12 white-tailed deer (Odoco ileus virginianus) during 1971 to compensate for a paucity of deer in the p ark and surrounding lands. By 1991 the Chickamauga deer population had incr eased to an estimated 200-500 individuals. We examined the genetic effects of this population bottleneck by determining the following measures of gene tic diversity: mean multilocus heterozygosity ((H) over bar), mean number o f alleles per locus ((A) over bar), and percentage of polymorphic loci (P). Tissue samples collected from 135 deer during 1991-1992 were subjected to starch-gel electrophoresis at 37 presumptive loci. Genetic variation in the Chickamauga herd ((H) over bar = 0.084, (A) over bar = 1.54, P = 29.73) wa s not significantly different from that observed by other researchers in Te xas deer (the original stocking source for Chickamauga deer) or five other unrestocked ("native") herds in the southeastern United States. Two loci (A at-2, 6-Pgd) were monomorphic in the Chickamauga herd but polymorphic in na tive herds. Rapid growth of the restocked Chickamauga herd in a protected h abitat, and potential gene flow from nearby relict deer populations, may ha ve been responsible for preventing substantial loss of genetic variation in the Chickamauga deer population.