Western Swamp Tortoise
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| Western Swamp Tortoise | ||||||||||||||||
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| Pseudemydura umbrina (Seibenrock, 1901) |
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Emydura inspectata (Glauert, 1954) |
[edit] Description
The Western Swamp Tortoise (Pseudemydura umbrina[1]), also known as the Western Swamp Turtle, is a short-necked freshwater tortoise that monotypically represents the sub-family Pseudemydurinae[2]. Adult males do not exceed a length of 155mm or a weight of 550g. Females are smaller, not growing beyond 135mm carapace length or a weight of 410g. Hatchlings have a carapace length of 24-29mm and weigh between 3.2 and 6.6g[3].
The colour of the Western Swamp Tortoise varies dependent on age and the environment where it is found. Typical coloration for hatchlings is grey above with bright cream and black below. The colour of adults varies with differing swamp conditions, and varies from medium yellow-brown in clay swamps to almost black with a maroon tinge in the black coffee-coloured water of sandy swamps. Plastron colour is variable, from yellow to brown or occasionally black; often there are black spots on a yellow background with black edges to the scutes. The legs are short and covered in scale-like scutes and the feet have well-developed claws. The short neck is covered with horny tubercles and on the top of the head is a large single scute. It is the smallest chelid found in Australia.
The only other species of freshwater tortoise occurring in the southwest of Western Australia is the Oblong Tortoise (Chelodina oblonga). It has a neck equal to or longer than its shell, making the two species easily identifiable.
The first specimen of the Western Swamp Tortoise was collected by Ludwig Preiss in 1839 and sent to Vienna Museum. There it was labeled New Holland and was named Pseudemydura umbrina 1901 by Seibenrock. No further collection of specimens were recorded until 1953. Glauert in 1954 named these specimens Emydura inspectata but in 1958 Ernest Williams of Harvard University showed them to be synonyms of P. umbrina, collected by Preiss[3].
[edit] Distribution
The Western Swamp Tortoise has been recorded only in scattered areas on the Swan Coastal Plain in Western Australia, from Perth Airport to near Pearce Royal Australian Air Force Base in the Bullsbrook locality. (roughly parallel with the Darling Scarp)[3]. Most of this area is now cleared and either urbanised or used for intensive agriculture.
Threatening factors to population and habitat were assessed as making this species vulnerable to extinction, and described as Critically Endangered on the 1996 IUCN Red List. The 2007 Red List notes this as outdated, and the conservation status requires reassessment.[4]
[edit] References
- ^ Siebenrock, F. (1901) Beschreibung einer neuen Schildkrötengattung aus der Familie Chelydridae von Australien. Sitzungsber. Akademie Wiss. Wien math. nat. Kl., Jahrg. 1901, 248-258.
- ^ Gaffney, E.S & Meylan, P.A. (1988) A phylogeny of turtles. In: Benton, M.A. (ed), The phylogeny and classification of tetrapods, Volume 1: Amphibians, Reptiles, Birds. Systematics Association Special Volume No. 35A, pp. 157-219. Clarendon Press, Oxford.
- ^ a b c Burbidge, A & Kuchling, G. (2004) Western Swamp Tortoise (Pseudemydura umbrina) Recovery Plan, Department of Conservation & Land Management, Western Australia. Available at http://www.environment.gov.au/biodiversity/threatened/publications/recovery/p-umbrina/index.html
- ^ Pseudemydura umbrina.. Tortoise & Freshwater Turtle Specialist Group 1996. In: IUCN 2007. 2007 IUCN Red List of Threatened Species.. IUCN.
