The short-eared rock-wallaby (''Petrogale brachyotis'') is a species of

rock-wallaby The rock-wallabies are the wallabies of the genus ''Petrogale''. Taxonomy The genus was established in 1837 by John Edward Gray in a revision of material at the British Museum of Natural History. Gray nominated his earlier description of ''K ...

found in northern

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, in the northernmost parts of the

Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...

and

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

. It is much larger than its three closest relatives, the eastern short-eared rock-wallaby (''Petrogale wilkinsi''), the nabarlek (''Petrogale concinna'') and the monjon (''Petrogale burbidgei'').

Taxonomy

The species was described by John Gould in 1841. In 2014 a genetic and morphological study identified a separate species, the eastern short-eared rock-wallaby (''Petrogale wilkinsi''), previously thought to be ''P. brachyotis''. It occurs in the Kakadu and

Litchfield National Park Litchfield National Park, covering approximately 1500 km2, is near the township of Batchelor, Northern Territory, Batchelor, 100 km south-west of Darwin, Northern Territory, Darwin, in the Northern Territory of Australia. Each year the ...

s, weighs less, and has stronger markings and colouring. Prior to a revision of the genus in 2014, a number of subspecies had been recognised. A tentative arrangement of two subspecies were proposed in that revision, identifying a taxon that may be a third species as the subspecies ''Petrogale brachyotis victoriae''.

Description

A species of '' Petrogale'', known as rock-wallabies, that varies in its size and coloration and has been recognised as a species group. Referred to as the ''brachyotis'' species group of the genus, they exist in an area that has made study difficult, although examination of specimens in 2014 separated one species and identified other cryptic taxa within the population. Prior to its revision, the generalised description for the species ''Petrogale brachyotis'' (''

sensu lato ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular co ...

'') incorporated variations later recognised as distinctive characters. The grey-brown coloration of the fur is interspersed with silver hair that highlights the overall coloration. the underside is pale grey. The length of the head and body combined is from , and they weigh . The tail is relatively short for the genus, , a dark brown to blackish tuft of fur appears at the terminus and the colour is otherwise cinnamon brown. The ears are also relatively small, less than half the length of the head, measuring from . The cinnamon colour also appears at the legs, broken by a buff or whitish stripe at the thigh that extends over the flank and over the shoulder, where a darker patch appears below the forelimb. A buff patch at the side of the snout has an off-white coloured stripe below that reaches to the eye. A dark stripe beginning at the crown of the head continues to the middle of the back. All the coloration is duller and the striping less distinct in populations found at the Victoria River and Kimberley region. The nominate subspecies bases its description of a specimen collected at Hanover Bay. There is a second subspecies, described by four specimens of a population that may be elevated to species rank after examination of more material. The holotype of ''Petrogale brachyotis victoriae'' was obtained in 1974 at Lobby Creek in the "Bradshaw" region of the Northern Territory. The population is only known from collections made near the Victoria River, inspiring the authors to propose that name as the taxon's epithet.

Behaviour

The short-eared rock-wallaby is a gregarious vegetarian, found in rocky hills and gorges. It is variable in its appearance but is generally grey-brown with white areas around its face and legs. It is not considered threatened.

Distribution and habitat

''Petrogale brachyotis'' has a patchy occurrence within a wide distribution range, extending west from the border of Queensland and the Northern Territory through the

Top End The Top End of Australia's Northern Territory is a geographical region encompassing the northernmost section of the Northern Territory, which aside from the Cape York Peninsula is the northernmost part of the Australian continent. It covers a ...

to the Windjana Gorge in northwestern Australia. The range inland is limited to areas of rainfall above the 600 mm isohyet. They are also found as island populations in the

Gulf of Carpentaria The Gulf of Carpentaria is a sea off the northern coast of Australia. It is enclosed on three sides by northern Australia and bounded on the north by the eastern Arafura Sea, which separates Australia and New Guinea. The northern boundary ...

. The favoured habitat is monsoonal rainforest and open grasslands, where they inhabit cliffs, hills and valleys that provide refuge and forage.

In Aboriginal language and culture

Speakers of Kunwinjku in West

Arnhem Land Arnhem Land is a historical region of the Northern Territory of Australia. It is located in the north-eastern corner of the territory and is around from the territorial capital, Darwin, Northern Territory, Darwin. In 1623, Dutch East India Compa ...

call the wallaby ''badbong'', and people would traditionally travel with spears into the escarpment to hunt them. According to Kunwinjku elder Reverend Peterson Nganjmirra they would trap badbong in rocky country by setting fire to "spinifex" (actually ''Triodia'' spp.).

Conservation

The IUCN ''Red List'' notes the

conservation status The conservation status of a group of organisms (for instance, a species) indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservation ...

of the species was assessed as least concern in 2015. The trajectory of the population is not known. Local extinctions are known to have occurred in the southern range in the Northern Territory, the subpopulation in Western Australia has not been historically surveyed. Altered fire regimes may detrimentally affect local populations of the species, and the IUCN advisory group recommends study of the effect of this and other factors on this poorly monitored species.

References

External links

Animal Diversity Web
{{Taxonbar, from=Q209628 Macropods Mammals of Western Australia Mammals of the Northern Territory Marsupials of Australia Mammals described in 1841 Taxa named by John Gould