Gopher tortoises Gopherus polyphemus, native to south-east USA, have declined greatly, primarily due to habitat loss. Relocation (translocation) is one technique being used in an attempt to mitigate for otherwise loss of tortoise populations on land subject to development. Previous relocations have generally been poorly documented and usefulness for tortoise conservation is unclear. In this study, the outcome of such a relocation attempt is reported.
Tortoises were moved 25 km from the Regional Development Center (RDC) site in Palm Beach Gardens (to become a business and residential complex) to Okeeheelee County Park (OK). Both sites comprised primarily cabbage palm flatwood habitat. OK was chosen as the best release site, being close to the donor site and containing 40 ha of appropriate habitat with restricted public access. Relevant literature was consulted to estimate the amount of habitat needed by tortoises.
In 1985, 82 tortoises were captured (bucket trapping, opportunistic captures and luring tortoises from burrows). Seven died from overheating while in bucket traps; subsequently exposed traps were shaded with palmetto fronds. Each tortoise was marked with a unique pattern of holes drilled in the marginal scutes, and plastron and carapace length recorded.
The remaining 75 tortoises were relocated to four holding pens (each 7.5 x 7.5 m) at OK within 6 h of capture at RDC. Five ‘starter’ burrows were dug in each. Each tortoise was randomly assigned to a pen and the number of days penned (duration 0 to 15 days). Individuals were released immediately outside the pen when their designated penning time was completed. In 1987, OK was surveyed to determine relocation success.
Two years after release, 35 tortoises were still alive and an apparently stable population had formed. Successful reproduction was occurring, one of three females X-rayed in 1987 being gravid and three young tortoises (1-year age class) observed.
This study indicates that it is possible to relocate gopher tortoises fairly successfully in suitable habitat. It does not support suggestions of previous reports that social structure determinants e.g. sex and size, gravidity, or on-site penning before release, influence success rate.
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