Western pebble-mound mouse or Ngadji, species ''Pseudomys chapmani'', is a burrowing and mound building

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...

in the family Muridae. They occur in the Pilbara, a remote region in the northwest of Australia.

Taxonomy

The species was described by D.J. Kitchener in 1980.Pseudomys chapmani Kitchener, D.J. 1980
A new species of ''Pseudomys'' (Rodentia: Muridae) from Western Australia
''Records of the Western Australian Museum'' 8:3 405-414 05 The population was formerly assumed to be species '' Pseudomys hermannsburgensis''. The description is based on a specimen that was collected at Mt Meharry (West Angelas Mine Site). The specific honours the biologist Andrew Chapman, who worked at the mammal department of the W.A. Museum. The common name according to the ''Census of Australian Vertebrates'' (ABRS 2001) is "Pebble-mound Mouse", a name given to sister taxon ''P. hermannsburgensis'' and so appended with 'Western' by the author of the species and others in later publications. The earlier name of 'sandy inland mouse' became applied in treatments as ''P. hermannsburgensis''. The extant name of the animal in the language of its region is Ngadji.Start, A.N., Anstee, S.D. & Endersby, M. 2000. A review of the biology and conservation status of the Ngadji, ''Pseudomys chapmani'' Kitchener, 1980 (Rodentia: Muridae). ''CALMScience'' 3: 125-147 The type specimen was collected by J.N. Dunlop in 1979, using a pit trapping method. A revision by Kitchener of specimens in the collection at the W.A. museum revealed morphological differences, observed in the Dunlop specimen, in previous collections of ''P. hermannsburgensis'', including those made at Woodstock Homestead in the Pilbara.

Description

The colour of the mouse's pelt is buff brown, darker to blackish at the head. The paws are white beneath and buff above, The underparts are white, up to the throat and mouth. The species resembles the related ''P. hermannburgensis'', the morphology is distinguished by smaller ears, feet and tail. The feet do not exceed 16 millimetres in length.

Habitat

It is native to and found only in

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

, where it lives in pebbly soils in arid tussock grassland and acacia woodland. Like other pebble-mound mice, the western pebble-mound mouse creates its own microhabitat by scattering a mound of pebbles around its burrows. The air temperature around the pebbles warms up faster in the morning than the pebbles themselves, causing the formation of small droplets of dew by condensation. The vegetation at the preferred habitat, hummock grasslands, is '' Triodia basedowii'', '' Cassia''. '' Acacia'' and '' Ptilotus'', and it is associated with eroding sands at natural features which expose small stones (pebbles). The species at the type location were the spinifex ''Triodia basedowii'' and '' T. pungens'', '' Acacia aneura'', and '' Cassia desolata'' and '' C. helmsii'', these cassias intermittently occur with ''

Eucalyptus gamophylla ''Eucalyptus gamophylla'', commonly known as warilu, blue-leaved mallee, twin-leaf mallee, twin-leaved mallee or blue mallee, is a species of mallee that is native to Western Australia, South Australia and the Northern Territory. It usually ha ...

'' and '' E. oleosa'' at the surrounding

gibber plain A desert pavement, also called reg (in the western Sahara), serir (eastern Sahara), gibber (in Australia), or saï (central Asia) is a desert surface covered with closely packed, interlocking angular or rounded rock fragments of pebble and cob ...

Status

The species occurs as disjunct populations within its range. The range is subject to changes in land use resulting in loss of habitat, and noted as contracting. According to the 2008 IUCN Red List of Threatened Species, the species is restricted to the non-coastal, central and eastern parts of the

Pilbara The Pilbara () is a large, dry, thinly populated region in the north of Western Australia. It is known for its Aboriginal peoples; its ancient landscapes; the red earth; and its vast mineral deposits, in particular iron ore. It is also a g ...

, Western Australia. It was formerly more widespread.

References

* ** * {{Taxonbar, from=Q1768641 Pseudomys Mammals of Western Australia Rodents of Australia Mammals described in 1980 Taxa named by Darrell Kitchener Taxonomy articles created by Polbot