Florida's Keystone Species
Breeding = spring, summer
Habitat = grasslands, flatwoods, scrub
Scientific name: Gopherus polyphemus
Common name: gopher tortoise
Habitat: Well-drained sandy areas with little tree cover and abundant herbaceous groundcover.
Physical description: Terrestrial tortoise, adults typically 10–15 inches long with an oblong brown or gray shell. Short but strong elephant-like back legs and shovel-like front legs to help dig.
Weight: 8–15 lbs.
Reproductive rate: Clutch sizes range from 3 to 15 eggs with an average clutch size of 5–8. Eggs hatch after 80–100 days depending on temperature.
Lifespan: 40–80 years and possibly older in the wild, up to 100 years in captivity.
Dispersal and home range: Although gopher tortoises are capable of moving long distances (0.6 mi), they are generally quite sedentary, and little is known about their dispersal. Home range varies with habitat, season, and sex of tortoise, but males move more frequently and have larger home ranges than females. Different studies have reported annual average home ranges of 1–114 acres for males and 0.2–14 acres for females.
Biology and behavior: Gopher tortoises are most active during April–October, but in southern Florida they are also active on warm days in winter. They live in excavated burrows that are an average of 15 feet long and 6.5 feet deep and provide shelter from weather, fire, and predators. Each burrow has a single entrance, about as wide as the length of the tortoise. Burrows are typically easy to spot because of the sandy "apron" or mound at the entrance. Gopher tortoises are herbivores that feed on low-growing vegetation such as grasses and legumes, and other herbaceous plants. They obtain most of their water from the plants they eat and rarely seek water to drink, usually only in a drought. Tortoises do not reach sexual maturity until about 10–15 years of age and tend to mature faster in areas where food resources are abundant. During the breeding season, males visit female burrows within a colony and court the resident females by bobbing their heads, nipping at the females' shells, and rubbing against the females in order to distribute pheromones from scent glands on their legs. Females lay their eggs in the sand mound at the burrow entrance or in another open, sunny spot. Predation of eggs and hatchlings is high. Females may only have one successful clutch every 10 years.
History and distribution: Gopher tortoises descended from a species of land tortoise that occupied western North America about 60 million years ago. Today, only five tortoise species remain in North America and the gopher tortoise is the only one that occurs east of the Mississippi River. Human activities and loss of habitat have eliminated the gopher tortoise from parts of its historic range in North Carolina, northern Alabama, western Louisiana and eastern Texas.
Threats: Habitat loss resulting from human development poses the greatest risk to gopher tortoises. When development fragments large blocks of habitat, tortoises are left with less suitable land. Often this fragmented land cannot be enhanced with prescribed fire, tortoises cannot disperse, and the potential increases for tortoises to be harmed or killed in interactions with humans, pet species (i.e., dogs), and vehicles. Fire suppression and dense tree coverage degrades gopher tortoise habitat by reducing light to the canopy floor, and thus growth of ground cover. With proper permits (contact your local Florida Fish and Wildlife Conservation Commission office), gopher tortoises living on proposed development sites may be relocated to a new area; however, relocations are often unsuccessful because the tortoises rarely stay at their new sites, may spread disease, and may disrupt resident tortoise populations. Several management plans by the Florida Fish and Wildlife Conservation Commission and USDA's Natural Resource Conservation Service are being implemented to restore and maintain gopher tortoise habitat and populations.
Did you know?
Gopher tortoises are a keystone species, meaning other animals depend on them for survival. The burrows created by gopher tortoises are used by more than 350 other species, called commensals, including the burrowing owl, Florida mouse, gopher frog, and eastern indigo snake.
Gopher Tortoise Fast Facts
Gopher tortoises feed on a variety of plants and also spread and fertilize seeds through their dung.
Gopher tortoises cannot swim! Never relocate a tortoise to water.
The longest recorded gopher tortoise burrow was over 47 feet long!
How You Can Help
Grow native gopher-tortoise-friendly plants on your property such as wiregrass, broadleaf grasses, wild peas, blueberries, and prickly pear.
State law protects gopher tortoises and their burrows. Only permitted individuals are allowed to relocate them. Please do not harass, pursue, or molest them.
Avoid mowing, driving over, or disturbing the area around a burrow; and never block a burrow opening.
Report gopher tortoise locations using this app, http://myfwc.com/wildlifehabitats/managed/gopher-tortoise/app/.
More information and factsheets at https://edis.ifas.ufl.edu