Variable breeding dates among populations of white-tailed deer in the southern United States: The legacy of restocking?

Reproduction is timed so that parturition coincides with optimal conditions for offspring survival, with strong fitness implications in northern regions. However, in the southern United States the breeding season of white-tailed deer (Odocoileus virginianus) is relatively heterogeneous over short distances. To test the hypothesis that genetic differences account for heterogeneity in breeding dates, we compared the degree of mitochondrial (mtDNA) and microsatellite DNA differentiation among 6 pairs of adjacent populations with breeding dates differing by an average of 35 days (DBD group) and 4 pairs of populations displaying similar breeding dates (SBD group) differing by no more than 2 days. Average mtDNA differentiation between pairs in the DBD group (F-ST=0.408, SD=0.190) was larger (P=0.03) than for the SBD group (F-ST=0.140, SD=0.092). The average differentiation at biparentally inherited microsatellite loci within the SBD group (F-ST=0.028, SD=0.021) did not differ from that observed for the DBD group (F-ST=0.047, SD=0.024; P=0.200). The similarity at biparentally inherited loci suggests that there are no cryptic barriers and populations are connected by male dispersal. The greater differences in mtDNA lineages between geographically proximate populations in the DBD group imply a maternal genetic effect on the timing of breeding, likely maintained by female philopatry. We hypothesize that this difference is a genetic legacy of restocking efforts and the recovery of remnant localized populations. Translocation efforts require careful consideration of differences between source and recipient populations. Breeding dates that differ among some proximate southern deer populations may be a fixed trait that must be considered when establishing management objectives and harvest criteria. (c) 2015 The Wildlife Society.