Large-scale declines in North American box turtle (Terrapene spp.) populations have been attributed to habitat fragmentation as a result of urbanization. We compared microsatellite markers and mitochondrial control region sequences of Ornate Box Turtles (Terrapene ornata) in two populations (a natural and an urban habitat) to test two hypotheses. We hypothesized that urban populations of T. ornata experience genetic bottlenecks due to road mortality and habitat fragmentation, and that roadways represent a barrier to gene flow among turtle populations, resulting in increased fragmentation of gene pools. Both populations shared similar allelic diversity and observed heterozygosity, with eight and seven of twelve microsatellite loci exhibiting heterozygote deficiency in the natural and urban populations, respectively. The number of mitochondrial control region haplotypes in the urban population was nearly four times that of the natural population, although only one haplotype occurred in appreciable frequency in both populations. We did not detect conclusive evidence of a recent genetic bottleneck in the urban population, thereby rejecting our first hypothesis. We detected weak differentiation among populations on opposing sides of a large highway, but did not detect any evidence of population structure, thereby rejecting our second hypothesis. This study indicates that a population of T. ornata with moderate road mortality currently has high genetic diversity, moderate inbreeding, and displays some evidence of genetic differentiation, but no conclusive evidence of recent genetic bottlenecks or unique genetic clustering. We suggest this is primarily due to the species long generation time and is a positive aspect of their life-history.
Survival and recruitment in a human-impacted population of Ornate Box Turtles, Terrapene ornata, with recommendations for conservation and management.
Isolation and characterization of eight polymorphic microsatellite loci for the three-toed box turtle (Terrapene carolina triunguis) and cross-amplification in other Terrapene species.
Mol. Ecol. Resour.9:
From forests to grasslands: life-history, road mortality, and genetic diversity of box turtles. In:
Reptiles in Research: Investigations of Ecology Physiology and Behavior from Desert to Sea p.
Characterization of ten novel microsatellite loci for the threatened ornate box turtle, Terrapene ornata.
Conserv. Genet. Resour.1:
Highways block gene flow and cause a rapid decline in genetic diversity of desert bighorn sheep.
Recent habitat fragmentation caused by major roads leads to reduction of gene flow and loss of genetic variability in ground beetles.
P. Roy. Soc. Lond. B Bio.2003:
High genetic diversity and no inbreeding in the endangered copper redhorse, Moxostoma hubbsi (Catostomidae, Pisces): the positive sides of a long generation time.
Migration, gene flow, and genetic diversity within and among Iowa populations of ornate box turtles (Terrapene ornata).
Chelon. Conserv. Biol.7:
FAST-TRACK: A southern California freeway is a physical and social barrier to gene flow in carnivores.
SmithM. (2004): Box turtles in Texas: a review of natural history and call for conservation action. http://www.gctts.org/BTPT/Box_Turt_in_TX-Nat_Hx_Cons_Jul04.pdf
Molecular systematics, phylogeography, and the effects of Pleistocene glaciation in the painted turtle (Chryseyms picta) complex.