Gopher tortoises have been on the move. Last month, the males were out searching for mates. Now some females are starting to lay eggs. Please slow down when you are driving and look for these gentle creatures crossing roads, in search of mates or nest sites. If you see one crossing a road, move it in the direction it was traveling in. Use gloves if you have them handy in your car.
The gopher tortoise (Gopherus polyphemus) is Florida’s official state tortoise, which makes sense as it’s also out only native tortoise. It’s one of the oldest living species, originating from a group of tortoises that lived here 60 million years ago. Gopher tortoises used to be well-established on Florida’s sandy uplands, but have declined some 80 percent over the last hundred years. Since 2007, they have been listed as threatened.
Built to dig
Their name, borrowed from the well-known digging mammal, recognizes their ability to excavate large burrows. The forelimbs of these reptiles are flat and shovel-shaped, ideal for tunneling into dry, well-drained soil or sand. The burrow entrance is shaped like a dome or half-moon, like a tortoise in cross-section.
Burrows are as wide as the tortoise is long (to facilitate turning around) and range from six to 10 feet deep and 15 to 40 feet long. A tortoise burrow has only one opening. Their burrows are essential to the gopher tortoise’s survival, since they protect the tortoise from the sun, predators and fires that naturally occur in their dry uplands habitat.
Because their burrows shelter about 360 other species of animals (such as burrowing owls, gopher frogs, quail and snakes), the gopher tortoise is a “keystone species.” Removing a keystone species can have a detrimental effect for ecosystems. Even animals that don’t usually share space with tortoises utilize their burrows to escape wildfire. Where there are no tortoises to dig these emergency shelters, many species suffer higher mortality during fires.
Threatened by development
Even if a burrow doesn’t show obvious activity, that doesn’t mean it isn’t being used. According Florida Fish and Wildlife Conservation Commission, “Gopher tortoises and their burrows are protected by state law, and a gopher tortoise relocation permit must be obtained from FWC before disturbing burrows and conducting construction activities. A disturbance includes any type of work within 25 feet of a gopher tortoise burrow.” If construction can’t avoid the burrow by 25 feet, a permit from the FWC is required.
Prior to 2007, developers could pay mitigation fees to plug up burrows and entombed thousands of tortoises, mostly under large commercial projects. Today, builders must purchase a permit to have a tortoise relocated according to FWC guidelines. Tortoises are released into temporary enclosures for six to 12 months and relocated into high-quality habitat. Permits and other useful information is on the FWC website at https://bit.ly/3bAok4u.
Few studies have evaluated the success of relocation, but results indicate that about half of the relocated tortoises either dispersed or did not survive their first year. If penned first, up to 92 percent survive.
Along with development come other threats to gopher tortoise survival, such as increased road mortality, use of pesticides and herbicides, disease from relocation and fire suppression, and attacks by domestic animals. The shells of young tortoises are pliable and provide little protection against gnawing dogs.
Female gopher tortoises lay four to six eggs which they bury in the sand. Often, they choose a site close to home: Right at the entrance of their burrow. Some also nest away from the burrow, or at the entrance of an old unused burrow. The eggs hatch about 3 months later. Hatchlings not destroyed by raccoons, dogs and feral cats often spend the first year in their mother’s burrow.
Move slow to live long
These slow-moving vegetarians live 40 to 80 years in the wild. The plants they eat provide the water they need. Although tortoises will sometimes drink, please do not place one in water — unlike their distant water-dwelling cousins, they are not good swimmers and might drown. If you see an injured creature, please call Wildlife Center of Southwest Florida at 941-484-9657 or the Peace River Wildlife Center at 941-637-3830.
Will our native gopher tortoise survive the next 25 years if the population of Florida expands by 40 percent as predicted? And what will happen to other species if the tortoises don’t make it? These are hard questions, but they have to be considered as we plan for the future of our state and its wildlife.