Florida’s only tortoise species is a relic of our desert past. It lives in deep burrows which are a key ecological factor for other species.
"Wild Florida" is a diary series that explores the flora and fauna of the Sunshine State.
Gopher Tortoise
There are five tortoise species living in North America, though fossils show that there have been around 25 previous species dating back to at least 60 million years ago (about the time that the dinosaurs died out). Four species—the Desert Tortoise (Gopherus agassizii), the Texas Tortoise (Gopherus berlandieri), the Bolson Tortoise (Gopherus flavomarginatus), and the Sonoran Desert Tortoise (Gopherus morafkai)—are native to the desert southwest.
The Gopher Tortoise (Gopherus polyphemus) is the only one found in the east, ranging from Florida up into Georgia, South Carolina, Alabama, and Mississippi. It somewhat resembles a Box Turtle but is much larger, and the tortoise is entirely terrestrial and never enters water. Historically, their favored habitat was the extensive Longleaf Pine forests that once blanketed much of the southeast. This habitat provided the deep dry sandy soil that the Tortoises like, and also an understory of grasses, cactus, blackberries, and other vegetation upon which the turtles feed.
The name “Gopher” comes from their extensive burrows, which the tortoises dig for protection from predators and weather, using their flattened elephantine front feet. These burrows can reach depths of over ten feet and extend underground for forty feet or more. At each point, the burrow is wide enough for the turtle to turn around, and the single entranceway is usually surrounded by an “apron” of excavated sand, which serves as a platform for the tortoise to bask in the sun. Pathways lead outwards to favored feeding and nesting spots.
These burrows are also important sources of shelter for other species which share the Tortoise’s habitat. At least 300 different species of animal and insect, including Gopher Frogs, Indigo Snakes, Burrowing Owls, Gopher Crickets, Florida Mice, and Eastern Diamondback Rattlesnakes, have been found living inside Tortoise burrows, either sharing it with the shelled occupant or moving in after the Tortoise has abandoned it. The burrows are particularly important as refuges during the periodic wildfires, sparked by lightning storms, that burn off the vegetation, renew the soil, and keep the understory open and sunny.
Unfortunately, the Longleaf Pine was favored by humans for use as lumber and as the masts for sailing ships, and over 90 percent of the original pine forest was wiped out by logging—and as their habitat declined, so did the Gopher Tortoise. Today, the Tortoise is listed as “threatened” or “endangered” in every state in which it is found. And because it is a “keystone species” upon which so many other species are dependent, loss of the Gopher Tortoise also leads to a cascading loss of other species as well—many of which, like the Indigo Snake and Florida Mice, are also threatened or endangered.
Efforts are being made in Florida to re-plant the Longleaf Pines back into areas in which they have been eradicated and to reintroduce the Tortoises, but the reptile’s biology makes this difficult. Nesting Gopher Tortoises lay only a dozen or so eggs at a time, and over 90% of all the nests in a given year normally fall victim to predators such as Raccoons, Armadillos, Foxes, Skunks, or Fire Ants. Those hatchlings which do survive grow very slowly, taking between 10 and 20 years to reach breeding size. In captivity, Gopher Tortoises have lived as long as 100 years, but their slow growth rate and their low reproduction makes it very difficult for wild populations to recover once they have declined from habitat loss.
The adults are sometimes attacked and eaten by Raccoons, who have learned to flip them over and tear open the soft parts underneath, but the primary cause of death for adult Gopher Tortoises are automobiles. Slow and lumbering, they are often hit by cars when trying to cross the road. In some areas, conservationists are installing tunnels under the roadway to allow the Tortoises to cross safely. Roadways are a particular danger for relocated Gopher Tortoises, who will often abandon their new home and attempt to crawl their way back to their previous territory.
In some areas, the local Gopher Tortoise population is threatened by diseases that have been introduced by the release of pet tortoises. In some parts of Florida, upper respiratory infections are spread from one turtle to another, and often prove fatal. This is one reason why it is now illegal to release any captive tortoise into the wild. Unfortunately, because the Tortoises are so easy to catch, a number of them are still illegally taken from the wild as pets.