The flatback turtle is named after its flat carapace, or shell, which is unlike the curved shell of other sea turtle species. The carapace is pale grayish-green in color with the outer margins distinctly upturned. An adult flatback weighs 200 pounds and is approximately 3 feet in length. They have the smallest distribution of all the species and breed and nest only in Australia.
Did You Know?
Flatbacks are preyed upon by Saltwater crocodiles, the largest reptile on earth. Adult females have been observed being attacked by crocs while attempting to nest.Despite its small range and non-migratory behavior, until now this has been the least studied of the sea turtle species, perhaps due in part to the remoteness of much of their habitat.
Facts & Tidbits
- In comparison to other sea turtle species that lay 100-200 eggs per nest, this species lays an average of 50 per nest. Their eggs and hatchlings however, are proportionally larger than other species, which may aid hatchlings in evading predators.
- The flatback is an omnivore, feeding on a variety of prey including sea cucumbers, jellies, soft corals, shrimp, crabs, molluscs, fish, and seaweed. Learn more about their diet.
- They are listed as Vulnerable under the Australian Commonwealth’s Endangered Species Protection Act. They are listed as data deficient by the IUCN Red List.
- Their scientific name is Natator depressus.
The flatback has the smallest geographic range of the seven sea turtle species. Their distribution is restricted to tropical regions of the continental shelf and coastal waters of Northern Australia, Southern Indonesia, and Southern Papua New Guinea. They do not have an oceanic phase or undertake long, open ocean migrations like other sea turtles, and are usually found in waters less than 200 feet in depth.
Breeding and nesting only occur in Australia with the largest concentration of females nesting on Crab Island in the NE Gulf of Carpentaria in Queensland. Primary nesting beaches are distributed from East to West across Queensland, the Northern Territory, and Western Australia.
Threats to this species include direct harvest for meat and eggs, incidental capture in fishing gear, destruction of nesting beaches from coastal development, pollution, and destruction of feeding habitat (coral reefs and shallow nearshore areas). Dingos and foxes once posed a significant threat to their nests but thanks to predator control programs, this threat has been greatly reduced.
Nests and hatchlings however are preyed upon by the Sand Monitor lizard, birds-including Night Herons and Pelicans, and feral pigs. In some areas, feral pigs consume almost all their nests.
What is SEE Turtles?
We protect sea turtles through conservation travel and volunteer tours, educational programs, and Billion Baby Turtles. We're a project of the Oceanic Society. Contact us for more information on flatback turtles.
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Photo credits: Catherine Bell, Jarrad Sherborne