Crest-tailed mulgara

The crest-tailed mulgara is a small to medium-sized mammal with sandy coloured fur on the upper parts leading to a darker grey on the under parts and inner limbs.[3] The species is strongly sexually dimorphic with adult males weighing 100 to 185 g (3.5 to 6.5 oz) and females weighing 65 to 120 g (2.3 to 4.2 oz).[4] Head-body length of 125–230 mm and tail length is between 75–125 mm.[3][4] Identification between the two species within the genus Dasycercus has proven difficult with the crest-tailed mulgara (Dasycercus cristicauda) often confused with the brush-tailed mulgara or ampurta (D. blythi). Tail morphology is a primary identifying feature between the two species.[2] The crest-tailed mulgara has a crest of fine black hairs along the dorsal edge of the tail creating a fin-like crest and hair length tapering towards the tip. In contrast the brush-tailed mulgara tail hair is not crested, black hair starts half way along the upper surface of the tail and dorsal hair length remains consistent.[3] Nipple count also differs between the two species and is another distinguishing feature. The female crest-tailed mulgara has eight nipples compared to the brush-tailed mulgara who only has six.[2][3][5]

There has been taxonomic confusion within the genus Dasycercus described by Peters in 1875.[3] Four named forms of carnivorous marsupials have been assigned to this genus.[3] Kreft, 1867, first described Chaetocercus cristicauda in 1877.[3] A second form, Phascogale blythi was described by Waite, 1904, followed by a third form, Phascogale hillieri described by Thomas, 1905.[3] Jones 1923, described two species of mulgara Dasycercus cristicauda and D. hillieri.[6] but decades on, William Ride’s 'A Guide to the Native Mammals of Australia' published in 1970 referred only to a single species, Dasycercus cristicauda, and in 1988 Mahoney and Ride placed all three species in the synonymy of D. cristicauda.[3] A fourth species, Dasyuroides byrnei, described by Spencer, 1896, was included by Mahoney and Ride however a lack of consensus resulted in its exclusion to the genus Dasycercus.[3] In 1995 Woolley described two sub-species, D. cristicauda cristicauda and D. cristicauda hillieri,[7] which were later confirmed to be two species using mitochondrial gene sequencing by Adams, Cooper and Armstrong in 2000. Woolley resolved the taxonomic and nomenclatural issues in 2005 and the species was re-named to two genetically distinct forms, D. cristicauda previously D. hillieri or the Ampurta and D. blythi previously named D. cristicauda or the Mulgara.[3]

The crest-tailed mulgara inhabits areas of arid Australia. It has been recorded in the southern Simpson Desert near the tri-state border and in the Tirari and Strzelecki Deserts of South Australia and the western Lake Eyre region.[8] Historically the species’ geographic range was much larger incorporating areas from Ooldea on the eastern edge of the Nullarbor Plain and the Musgrave Ranges in South Australia, Sandringham Station in Queensland (last record in 1968)[9] and from the Canning Stock Route and near Rawlinna on the Nullarbor Plain in Western Australia.[8] Owl pellet examinations showed presence of crest-tailed mulgara near the southern and south-eastern margins of the Strzelecki dunefield/sandplain, in the Flinders Ranges and at Mutawintji National Park in far-western New South Wales.[10] Due to the levels of taxonomic uncertainty, misidentification may have led to an overestimated distribution especially when based on older records. This has created difficulties in assessing and interpreting temporal changes within its historic distribution.[11]

Wild Deserts Project, University of New South Wales, team member Reece Pedler holds a crest-tailed mulgara which was re-discovered in 2017 in Sturt National Park north-west of Tibooburra, Australia.

The following are the federal, state and international listings for the crest-tailed mulgara.[8] The mulgara was presumed extirpated in New South Wales for more than a century, but was re-discovered in 2017 in Sturt National Park north-west of Tibooburra.[13]

The crest-tailed mulgara is sensitive to predation by the European red fox and feral cat,[2] changes to fire regimes together with environmental degradation and habitat homogenization attributed to grazing from livestock and introduced European rabbits.[10][14] During post-release of rabbit hemorrhagic disease virus (RHDV), the crest-tailed mulgara underwent a 70-fold increase in its extent of occurrence and a 20-fold increase in its area of occupancy.[15]