Schwartz, T.S.*; Karl, S.A.: Genetic Structure of Florida Gopher Tortoise (Gopherus polyphemus) Populations
Gopher tortoise (Gopherus polyphemus) population sizes are believed to have declined by an estimated 80% in the past 100 years. Habitat destruction from human development, predation, and infection from upper respiratory tract disease (URTD) have contributed to this decline. We currently are using 7-10 microsatellite loci to investigating the genetic structure and phylogeography of 18 gopher tortoise populations throughout Florida. Estimates of inbreeding and migration have been determined for 5 of these populations. Effective population sizes (Ne) based on microsatellite data are being correlated with parallel field demographic studies. The occurrence of URTD will be compared to gene flow patterns among populations in an attempt to assess the potential association of migration with the spread of the disease. Microsatellite data will be used to evaluate the phylogeography of the tortoise within Florida, and to identify potential effects of isolation in the populations peripheral to the Brooksville and Lake Wales ridges. This research will provide estimates on population viability and help focus conservation efforts on this threatened species.
