Gopherus polyphemus Gopher Tortoise Class: Reptilia. Order: Testudines. Family: Testudinidae. Other names: Physical Description: The gopher tortoise is a terrestrial turtle with a domed shell and round, stumpy, elephantine hind legs that are well- adapted for digging. The carapace is brown to tan, with light-centered scutes; they usually have a yellowish plastron, grayish brown head, and dark brown irises. Head is large and blunt in front; hind feet are smaller than front feet; male plastron is concave. Adult gular scutes project beyond carapace, serving as a “head rest”, which is convenient, since they cannot pull their head all the way into their shell. They typically are 9¼ - 14½” in length, and weigh from 8-15 pounds. One of the most unique features of turtles and tortoises is their protective shell. Because of the shell, flight, running, and climbing are not evolutionary options! But some adaptive radiation occurs within the order. Turtles and tortoises inhabit marshes, lakes, rivers, and the open sea, as well as forests, grasslands and deserts. The top shell is called the carapace and the bottom shell the plastron. The carapace develops from a layer of skin and the backbone and ribs are fused to the carapace. The plastron is developed from the bones of the shoulder girdle. The shell is so successful that it is the cornerstone of turtle design and lends to the lineage’s longevity, while at the same time limiting species diversity. Diet in the Wild: Generally herbivorous: grass, leaves, wild fruit; may eat some insects; in captivity they readily accept leafy greens, vegetables, and fruit; some show an interest in meat. Diet at the Zoo: Tortoise biscuits, mustard greens, collard greens, escarole, romaine, sweet potato, carrot. Habitat & Range: Well-drained sandy areas between grasslands and forests. Found along the southern coast from South Carolina to Florida and along the Gulf Coast to extreme eastern Louisiana. They dig long, wide burrows which may reach 35 feet in length. Life Span: Up to 80 years in the wild (typically 40-60 years); up to 100 years in captivity. Perils in the wild: Some mammals and birds of prey eat hatchlings. The automobile takes its toll each year as the slow-moving turtle attempts to creep across busy streets, highways, and railroad tracks. The biggest peril is from habitat destruction and/or fragmentation (which is defined as habitats separated by human land usage) causing small, isolated populations that sometimes suffer from inbreeding. Physical Adaptations: Heavily scaled forelimbs, when folded, close the opening of the shell and provide good protection for the head and neck. Gopher tortoise’s have front feet that are well adapted to digging their burrows, and elephantine rear feet for walking. This type of foot adaptation is common in terrestrial turtles and tortoises. 05/2013 See “physical description” above for more information on the design of the turtle’s shell. Behavioral Adaptations: Diurnal. Typically emerge from burrow when the day gets warm and feed until early afternoon. Mostly solitary and territorial. Most gopher tortoises will occupy the same burrow for most of, if not all, of their life. Gopher tortoises are accomplished burrowers, having immovable wrists that give their forelimbs a shovel-like movement and great power. Their tunnels slope downward from the surface and then usually level off underground, and may be up to 35 feet long and wide enough so that the animal may turn around at any point along its length. The burrow, which is a permanent home, is kept painstakingly free of debris. The very stable temperature and humidity within the burrow protect the tortoise from the alterations of climate which may occur on the surface. Because the weather in their range is cooler and more humid, gopher tortoises may remain active through the hottest hours of the day. They enter short periods of hibernation only if the weather becomes severe. Reproduction and Development: Gopher tortoises are slow to reach sexual maturity – at 10 to 20 years of age. They have a low reproductive rate, and a total of only 3-5% of their young typically survives. The breeding season typically spans March-December, but most eggs are laid during May and June. When courting, a male gopher tortoise will circle the female and bob his head up and down to attract the female. When this succeeds, the male then bites the female on the leg and the front edge of the shell, which usually initiates mating. Females deposit 1-25 (typically 5-8) white, spherical eggs at the entrance of their burrows to capture heat, making them prey to raccoons and other predators. After an incubation period of 80- 110 days, depending on latitude, the eggs hatch and the young dig their way to the surface. Hatchlings are 1 ½” in length with large yellow or orange spots on their carapace. Additional Information: The gopher tortoise is a keystone species, which is a species that has a disproportionally large effect on its environment. Keystone species play a critical role in maintaining the ecological community where they live through their effect on the ecosystem and the other plants and animals that live there. For the gopher tortoise, this is mostly due to the diverse group of animals that utilize and depend upon the burrows created by the gopher tortoise. Many other animals seek shelter or live permanently in “gopher” burrows. These run the gamut from insects to burrowing owls, raccoons and opossums, gopher frogs, indigo snakes, diamondback rattlers, toads, and various invertebrates. As such, gopher tortoises are very important animals in their ecosystem, and are considered a keystone species. Like the desert tortoise, gopher males are normally placid except during the mating season. When two males meet, they nod their heads rapidly and perhaps touch noses before continuing their separate ways. However, during the mating season, a fight may ensue. Each draws back and then rushes toward the other, using the gular scute projecting forward from the plastron to butt one another in the hopes of tipping over one’s adversary. According to one source, certain Indian tribes once used the gopher tortoise as a form of money. Its shell was used to make baskets and pots. 05/2013 Conservation Status: IUCN Status The IUCN has assessed the gopher tortoise as “Vulnerable” (VU) – High risk of endangerment in the wild. The tortoise is listed as a Threatened Species under the U.S. Endangered Species Act and is protected by State law in many of its range states. Conservation Efforts: There are conservation efforts underway to protect the gopher tortoise’s habitat in the Southeastern United States. One organization, “The Gopher Tortoise Council”, offers professional advice for management, conservation, and protection of gopher tortoises; it encourages the study of the life history, ecology, and management of gopher tortoises and other upland species, and also conducts active public information and conservation education programs, and seeks effective protection of the gopher tortoise and other upland species throughout the southeastern United States. Glossary: List of definitions of the most important recurrent technical terms used in the text. Carapace - The top shell of a turtle. The carapace develops from a layer of skin and the backbone and ribs are fused to the carapace. Diurnal – Active during daytime hours. Gular scutes – Enlarged scales on the plastron of a turtle which are located under the throat. Keystone species - A species that has a disproportionally large effect on its environment, and plays a critical role in maintaining the ecological community where they live through their effect on the ecosystem and the other plants and animals that live there. Named after the architectural term “keystone,” which refers to the wedge-shaped stone at the very top, or apex, of a masonry arch, which supports and essentially upholds the entire arch. Often, if a keystone species is removed from the ecosystem, a cascade of events occurs that greatly impacts the ecosystem (e.g. if a keystone predator is removed, its prey population explodes, which then overgrazes the local plant life, etc.). Plastron - The lower shell of a turtle, developed from the bones of the shoulder girdle. Scute - Any enlarged scale on a reptile; sometimes called a “plate”. Vulnerable (VU) – IUCN status which defines a “High risk of endangerment in the wild”. Sources: Cincinnati Zoo & Botanical Gardens http://www.benning.army.mil/garrison/DPW/EMD/gopher_tortoise.htm http://www.fws.gov/northflorida/GopherTortoise/Gopher_Tortoise_Fact_Sheet.html http://naturalhistory.uga.edu/~GMNH/gawildlife/index.php?page=speciespages/species_page&key =gpolyphemus 05/2013 .