The Mary River turtle (Elusor macrurus ) is an endangered short-necked turtle that is endemic to the Mary River in south-east Queensland, Australia. While the Mary River Turtle was first formerly discovered in 1994, they eluded discovery in their natural environment for nearly 30 years. There has been a dramatic decrease in their population due to low reproduction rates and an increase of depredation on nests.
The Mary River turtle is an endangered short-necked turtle that is found only in Australia. It is one of Australia's largest turtles. Adults of this species have an elongated, streamlined carapace that can be plain in colour or intricately patterned. Overall colour can vary from rusty red to brown and almost black. The plastron varies from cream to pale pink. The skin colouration is similar to that of the shell and often has salmon pink present on the tail and limbs. The iris can be pale blue.
Mary River turtles are native to southeast Queensland, Australia. They inhabit flowing and well-oxygenated sections of the Mary River basin from Gympie to Maryborough, using terrestrial nest sites. Their habitats consist of riffles and shallow parts that alternate with deeper pools. They prefer to live in clear and slow-moving water.
These turtles spend most of their time in the water and are powerful swimmers. They use bimodal respiration, and so are capable of absorbing oxygen via the cloaca whilst underwater, because of this, they can stay under the water for three days at a time. However, they do regularly come to the surface to breathe air in the usual way. Mary River turtles are solitary and interact with each other only during the mating season. Mature males may be aggressive towards other males, or turtles of other species.
Mary River turtles are omnivorous, eating algae as well as bivalves and other small animal prey, such as fish, frogs, and sometimes even ducklings.
Females of this species usually lay up to 15 eggs on the banks of rivers or streams. The young hatch precocial and are able to move around and find food on their own. They often stay together until they are old enough to protect themselves and live a solitary life. Mary River turtles take an unusually long time to mature; it has been estimated that females take 25 years, and males, 30 years to become adults.
Mary River turtles are endangered and face many threats. Their number one threat is the looting of their nests by dogs, foxes, and goannas. The land around the Mary River has been cleared many times leading to low-quality water and a build up of silt. Invasive plants along the river bank have also contributed to the lack of breeding success because they make it difficult for Mary River turtles to go ashore and lay their eggs. Hatchlings suffer from predation by Red foxes, wild dogs, and fish, especially when the turtles are at the hatchling and juvenile stages of their life.
The IUCN Red List and other sources don’t provide the number of the Mary River turtle total population size. Currently, this species is classified as Endangered (EN) on the IUCN Red List.
