Tortoise, Gopher


Gopherus polyphemus



The upper shell (carapace) is brown or tan, with growth rings evident on younger individuals, but these are worn away on adults. The under shell (plastron) is unhinged, dull yellowish in color, with the soft parts grayish brown. The upper shell averages 9 inches to 11 inches in length with the maximum measured at 15 inches. The feet are stumpy and without webs. Their heads are large and blunt. The exposed skin of the head, neck, and legs is grayish black.

Family

Testudinidae

Order

Testudines

Class

Testudines

Range

The gopher tortoise is found in the southeastern part of the United States - southwestern South Carolina, south almost to the tip of the Florida peninsula; west through southern Georgia, Alabama, and Mississippi, to Louisiana and the edge of southeastern Texas and Arkansas.

Habitat

Dry areas where sandy, well-drained soils persist, avoiding wet, swampy areas where the water table is less than 3 feet (1 m) below the surface. Soils in gopher tortoise habitats are often low in fertility but support a diversity of grasses. Elevations range from just above high tide to 330 feet above sea level (100 m).

Life Expectancy

40 to 60 years

Sexual Maturity

19 to 21 years in Georgia, 10 to 15 years in Florida

Diet

In the wild, gopher tortoises eat grasses and leaves with the occasional wild fruits and berries. In the Zoo, they are fed a commercially prepared tortoise chow, finely chopped carrots, broccoli, sweet potatoes, apples, bananas, green beans, endive, escarole, kale, and zucchini (same diet for the African spurred tortoise and the Aldabra tortoise).

Status

IUCN – Vulnerable, Florida (Species of Special Concern), CITES - Appendix II

Behaviors

The gopher tortoise can be found every month of the year with peak activity being May or June. The excavation of burrows is its main activity. The burrows, which are dug with their hind legs, on average measure 6.6 feet deep, 14.8 feet long and wide enough for turning around at any point. Depth is dependent on groundwater levels. These burrows give them a place to sleep and hibernate, where they are protected from enemies (snakes and carnivorous mammals) and harsh weather condition. They spend their nights in burrows, emerging daily in warm weather, usually in the morning before it gets too hot, to forage for food. Generally feeding activity is confined to within 164 feet of the burrow. Principal foods include grasses, legumes, and grass-like plants of the sedge and aster families. Fruits such as blackberries, papaws, gopher apples, and saw palmetto berries are also consumed. The mating behavior of the gopher tortoise is not well documented because of its secretive nature. Male gopher tortoises have been known to utter short rasping calls, to attract females. Fights between male and female gopher tortoises are also sometimes seen, which could be related to courtship and mating. Males have a pair of glands under their chins that may function to attract females. Mating season occurs from April through June. Nests are usually constructed in the burrow mounds from mid-May to mid-June. Eggs are laid shortly after mating and usually hatch in 80 to 90 days in Florida. Incubation times can vary, exceeding 110 days depending on temperature. Typically, four to 12 eggs are laid annually. A female may have only one successful brood every 10 years. Predation on nests is high. Raccoons, foxes, skunks, armadillos, coachwhip snakes, indigo snakes, and various raptors raid tortoise nests. The first years of life are the most critical. Gopher tortoises inhabit several plant communities that have remained undisturbed for up to about 11 years. As shade increased, the number of tortoises decreased.

Adaptions

The low profile of the gopher tortoise’s shell allows it to easily dig and navigate through its tunnels. The shell also offers protection from most predators. This turtle has shovel-like front legs, stumpy hind legs, and an unhinged plastron.

Special Interests

The genus name is the Latinized name of a small burrowing mammal, the pocket gopher, a reference to this turtle’s burrowing habits. The species name polyphemus was the name of the cave-dwelling giant in The Odyssey, an ancient Greek myth. It is presumably applied to this turtle for its burrowing habits and strength. Gopher tortoises dig long tunnels with spacious chambers at the end to keep temperatures constant The gopher tortoise is considered a keystone species because more than 80 symbiotic species live in and rely on its burrow for protection. Some of these species are rare, such as the dusky gopher frog (Rana areolata), the pine snake (Pituophis melanoleucus), and the indigo snake (Drymarchon corais). By burrowing, gopher tortoises aid in returning leached nutrients to the soil’s surface. As it grazes along feeding paths that radiate from the burrow, the gopher tortoise serves as a seed disperser for native plants.

Folklore

Ancient Indians had a monetary system that used gopher tortoises in the place of money. Shells of the tortoises were used as baskets, pots, and even sun helmets. Even today, they are a source of food for poorer rural people of Florida and South Georgia. Tortoises are known in legend and folklore for their leisurely ways and slow pace. The Florida gopher tortoise follows this legend well with a slow pace of between .27 and .5 miles per hour.

Conservation

The gopher tortoise has a vital community role and is known as a keystone species because of the wide use of their burrows by over 700 other animals (such as burrowing owls, raccoons, opossums, gopher frogs, snakes, etc.). Therefore, protection of the gopher tortoise is crucial for the whole ecosystem in which it lives. In some states, the gopher tortoise is being protected by state agencies that are enforcing conservation laws and controlling illegal harvest. Besides protecting the tortoise against poaching, other methods of conservation are also being used. Relocation of gopher tortoises has been used to protect tortoises found on land slated for development, but with limited success. Reintroduction into areas from which the tortoises were driven has also been used. Protection of gopher tortoise habitat, such as sand dunes and longleaf pine forests, is the best alternative to increase and maintain populations.

Jacksonville Zoo History

This species appears in the Zoo’s animal collection during April 1966. It has successfully bred here.

Exhibit

Wild Florida