Status: Endangered, FWS
Status: Critically Endangered, IUCN
Listed by FWS: June 2, 1970
Description: Turtle with a flat, rectangular light brown to black carapace.
Habitat: Shallow swamps and marshes; burrows in sandy soil or takes refuge under plant debris in dry season.
Food: Carnivorous; eats aquatic insects, crustaceans, and tadpoles.
Reproduction: Nests in October and November; clutch of three to five elongated eggs.
Threats: During low rainfall, dessication, predation by red foxes, and fire; and urban development.
Range: Australia (southwestern)
The western swamp turtle is a small sideneck whose 5.5 in (14 cm) flat, rectangular carapace has smooth posterior margins and a medial depression. The posterior marginals are elevated over the tail and the surface of the scutes is wrinkled and leathery. The color of the carapace is light brown to black. The plastron is very large and the broad bridge is one-third the size of the plastron. The undersides of the marginals are yellow with dark seams. The head is broad and flat with a short, slightly projecting snout. The head is covered with rough tuberculate skin and the neck is covered with large conical tubercles. The forelimbs are also covered with scales. The head, neck and limbs are brown and the jaws are yellowish. All toes are webbed.
Pseudemydura umbrina nests in October and November and the young hatch in about six months. The clutch contains three to five elongated eggs with brittle shells. Hatchlings that do not reach a sufficient size by the first wet season will not survive. Sexual maturity is not reached until 10-15 years of age. Females probably lay only one clutch per year, and the survival rate of hatchlings may be low, especially during seasons of low rainfall. The western swamp turtle is carnivorous, eating aquatic insects, crustaceans, and tadpoles.
The western swamp turtle lives in shallow swamps and marshes (depth of 8-18 in, or 20.3-45.7 cm) that fill during the winter rains but dry out completely during the hot arid summers. During the dry season the turtles dig burrows in sandy soil or takes refuge under plant debris.
This species is restricted to southwestern Australia where it ranges southward from Bullsbrook to the marshy areas in the suburbs of Perth.
A single specimen of the western swamp turtle was discovered in 1839, and it was not seen again until 1953, so the decline of the species is unknown. The breeding success of this turtle is dependent upon long periods of drought that trigger the breeding period, and adverse climate conditions may have affected this already rare species. During periods of low rainfall, hatchling succumb to dessication, to predation by red foxes, and because of wildfires. The known locations for the western swamp turtle lie within the suburbs of Perth, which is a thriving, growing metropolis that continues to encroach on possible habitat.
Two reserves, Ellen Brook and Twin Swamp, have been established within the range of the species to provide a protected area. However, the Twin Swamp population has become extinct. The captive breeding program at Perth has met with some success after initial failure when the breeding requirements of the western swamp turtle were not understood. More recently, the hatchling rate has been high and there is hope that a population can be reintroduced into a protected habitat.
Source: Beacham's Guide to International Endangered Species, Gale Group. 2001.