Population Structure and Nest Success of Gopher Tortoises (Gopherus polyphemus), and Vegetative Response to Prescribed Burning in Northeast Florida

A gopher tortoise population on the campus of University of North Florida is part of an ongoing study initiated during the early 1990s, and this project presents data on this population collected during the 2009-2011 field seasons. The project has three major objectives: 1) measure population demographics including density and structure to assess long-term viability and recruitment, 2) evaluate decadal growth rates of individuals by comparing measurements of tortoises captured and marked in the 1990-1994 study done at the same site with those tortoises recaptured during the current study, and 3) assess the effect of prescribed burning on vegetation. In total, 141 individuals were caught from 2009-2011: 32 adult females, 28 adult males and 17 young adults, 43 juveniles and 21 hatchlings. Of these, 39 are recaptures from the research performed in the early 1990s. Adult burrow aprons were probed using a wire survey flag in an attempt to locate nests. In 2010 we found two intact nests with this technique and recorded two other depredated nests that were unassociated with any burrow. In 2011 we found one nest and a clutch that was laid on the ground’s surface. Four 100m transects were established before prescribed burning began. Vegetation analyses were done bi-monthly and all plants were recorded as well as their percent of each plot. The most abundant plant was milkpea. Preliminary analysis of postburn response has indicated increased groundcover in all burned transects