Survivorship of Hatchling Gopher Tortoises
in North-Central Florida
LORA L. SMITH
Department of Wildlife Ecology and Conservation, University of Florida,
Gainesville, FL 32611, USA / e-mail: firstname.lastname@example.org
ABSTRACT: Gopher tortoises, Gopherus polyphemus, are declining in number throughout their range as a result of habitat degradation and urbanization. Under natural conditions, the low reproductive potential and low hatchling survival of the gopher tortoise is compensated by a long life span, low adult mortality, and the persistence of extensive, unchanging habitat. Human activities have altered habitat and predator-prey relationships. Although raccoons, Procyon lotor, historically probably had little effect on gopher tortoise populations, raccoon predation may presently play a significant role in limiting gopher tortoise numbers.
Hatchling survivorship in a north-central Florida gopher tortoise population was studied using a technique that employed lightweight metal tags and a metal detector to locate hatchlings. Survivorship of hatchlings within protective enclosures was compared to that of unprotected nests. Within the protective enclosures, 43% of the hatchlings released were alive after 280 days, compared to less than 20% from unprotected nests. Seven of the nine recovered dead hatchlings had been killed by a mammalian predator. Predation occurred even at protected nests, indicating that it is a very significant factor in hatchling gopher tortoise mortality.