Animal Spotlight: Gopher Tortoise

Taxonomy:

gopher tortoise.PNG
Credit: Randy Browning, US FWS
  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Reptilia
  • Order: Testudines
  • Family: Testudinidae
  • Genus: Gopherus
  • Species: polyphemus
  • Average Length: 10-12 inches (25.4-30.5 cm)
  • Average Weight: 6 lbs (2.7 kg)
  • Average Lifespan: 60 years

Named for their ability to dig large, deep burrows, gopher tortoises have since been eliminated from a significant portion of their historic range due to human activities. They still occur in Alabama, South Carolina, Louisiana, Mississippi, and Georgia. But, the majority of the remaining population is in Florida, where it is estimated to be under 800,000 in 2003.

They like to live in well-drained sandy areas with a sparse tree canopy and abundant low growing vegetation. They are commonly found in habitats such as sandhill, pine flatwoods, scrub, scrubby flatwoods, dry prairies, xeric hammock, pine-mixed hardwoods, and coastal dunes.

Physical Description

The shell is typically a light to dark brown, elongate upper shell and dull yellow plastron, the underside. The skin is greyish brown, the head is large and blunt, and hind feet are small and stumpy. The front legs in particular are designed to be shovel-like and black legs strong and sturdy to help the tortoise dig.

Male gopher tortoises have longer tails than females, with extended shells under their chins for ramming or butting. However, females are larger in size. In hatchlings, the scutes (polygon shapes covering the shell) are bright yellow with brown edges.

Diet:

desert-tortoise-eating-fruitGopher tortoises are herbivores, feeding on low-growing plants like wiregrass, broadleaf grasses, and legumes (bean family plants). They also feed on the fruits, flowers, and leaves of plants and shrubs like asters, daisies, clover, peas, cat briar, blueberries, and palmetto berries. They also like stinging nettle, prickly pear cactus, blackberries, pine needles, and other seasonal fruits.

Behavior:

Gopher tortoises are one of the few species of tortoise that dig burrows and this behavior is integral to the their survival. It provides shelter from the sun, stable temperature, relative humidity, and protection from predators. It also doubles as a site for laying eggs and as a crucial refuge for the tortoise and other species for the fires that naturally occur in its native ecosystem. Each tortoise has a well defined home range which contains several burrows, in which they spent most of their lives.

After sleeping at night in a borrow, the diurnal gopher tortoise will emerge to feed during the day. As it feeds, it “prunes” the plants it eats, leaving a healthy plant ready to send out new nutritious growth. Furthermore the seeds are fertilized and distributed in the scat throughout the tortoise’s’ home range.

In late spring and early summer (April to June), gopher tortoises engage in mating behavior. The males will visit the burrows of the females in their colonies. Gestures include communication through head bobbing, shell nipping, and rubbing of pheromones from scent glands on his legs.

About three months later, the female digs a nest at the mouth of her burrow or another sunny site to bury her ping-pong ball sized eggs of around one to 25 eggs. The white, spherical eggs are laid in batches of fix to six.

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Gopher tortoise burrow, © Florida Fish & Wildlife Commission

Approximately 100 days later, tiny hatchlings will hatch and dig their way to the surface. Like turtles, sex is determined by temperature. Eggs incubated at over 30 ºC will be females, and those below 30 ºC will be males.

Gopher tortoises are slow to reach sexual maturity. Females reach sexual maturity from as early as 9 to as late as 21 years of age, depending on local resource abundance and latitude. Males mature at a slightly younger age.

Conservation:

The primary threat is loss of habitat. The prime tortoise habitat (dry upland areas) are targeted by Floridian developers avoiding wetlands for new housing subdivisions, industrial centers, along with shopping centers and services.

When developers want to build on gopher tortoise habitat, they have to protect the area around the tortoises’ burrows or relocate them to a suitable protected area. And while relocation can save some, many of the tortoises don’t stay in their new location and will try to move elsewhere, making them vulnerable to exposure, predation, and roadkill. Even with relocation, moving the tortoises disturbs the natural community.

Gopher tortoises have suffered when predators and domestic pets kill them in inordinate numbers. Though predation is a natural occurrence in nature, when they are taken excessively, it could devastate a colony. With a low rate of reproduction, low hatchling survival, and late reproductive maturity, it could take many years for a colony to replace those individuals lost.

gopher-tortoise-2
Credit: Randy Browning, USFWS

Conversion of natural areas and forest lands into intensive agriculture like peanut farming has also become a major threat, as well as poor land management practices like fire suppression or pesticide use.

Gopher tortoises in Alabama counties west of the Mobile and Tombigbee Rivers and in Mississippi and Louisiana are currently protected by federal law under the Endangered Species Act. Others in regions in Florida, Georgia, southern South Carolina, and Alabama east of the rivers are being considered for possible listing later under the Act.

Interesting Facts

  • Gopher tortoises need relatively deep, sandy soils to borrow and open sunny sites for nesting. They thrive in longleaf pine forests and enjoy the same type of habitat as the endangered red-cockaded woodpecker.
  • Their borrows provide refuge for about 360 other species throughout its range
  • Only about 3 to 5% of young tortoises typically survive. Because the eggs are laid at the entrance of their burrows to capture the heat, it is easy for predators to eat them.
  • Gopher tortoises are reliant on the dy habitats experiencing frequent fires. Without the nature cycles of burning in pine forests, the dense vegetation shades out the tender herbs tortoises like to eat, limiting their food supplies.
  • The recorded length for a burrow is over 47 feet long but the average is 15 feet long.
  • Of the five North American tortoise species in the genus Gopherus, the gopher tortoise is the only one that occurs east of the Mississippi River.
  • Because gopher tortoises eat so much greenery, they get most of the water they need from those plants. They rarely need to drink water and usually only during a drought, when water-storing plants may not be as plentiful.
  • Florida celebrates its only native tortoise on April 10th, the official Gopher Tortoise Day.
  • Ancient Indians had a monetary system that used gopher tortoises in the place of money. Shells have served as baskets, pots, and even as sun helmets.
  • Today, they are a source of food for poorer rural people of Florida and south Georgia.

References + For More Reading:

Gopher Tortoise Basic Facts

Gopher Tortoise Threats

Gopher Tortoise (Gopherus polyphemus)

Florida Fish and Wildlife: Gopher Tortoise

Gopher tortoise

5 Fun Facts about Gopher Tortoises

Arkive: Gopher tortoise (Gopherus polyphemus)

IUCN: Gopherus polyphemus

Animal Diversity: (Florida) Gopher Tortoise

Please Stop ‘Rescuing’ Gopher Tortoises, Florida Aks

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One thought on “Animal Spotlight: Gopher Tortoise

  1. Pingback: Small Animals That Burrow | Purathrive

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