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{{Short description|Species of marsupial}}
{{Other uses}}
{{Speciesbox
| image             = Petrogale cocinna Gould Mamm Aust vol 2 plate 48.jpg
| image_caption     = ''Petrogale cocinna'' by John Gould and [[H. C. Richter]], ''Mammals of Australia'' (1863)
| status            = EN
| status_system     = IUCN3.1
| status_ref        = <ref name="iucn status 19 November 2021">{{cite iucn |author=Woinarski, J. |author2=Burbidge, A.A. |date=2016 |title=''Petrogale concinna'' |volume=2016 |page=e.T16761A21955087 |doi=10.2305/IUCN.UK.2016-1.RLTS.T16761A21955087.en |access-date=19 November 2021}}</ref>
| taxon             = Petrogale concinna
| authority         = [[John Gould|Gould]], 1842<ref name="Gould1842" />
| range_map         = Nabarlek area.png
| range_map_caption = Distribution within Australia (green)
| synonyms          = 
* ''Petrogale concinna canescens'' <small>(Thomas, 1909)</small>
* ''Petrogale concinna monastria'' <small>(Thomas, 1926)</small>
}}

The '''nabarlek''' ('''''Petrogale concinna''''') is a small species of [[Macropodidae|macropod]] found in northern [[Australia]]. They are a shy and nocturnal animal that resides in rocky hollows and forages in the surrounding area. Their diet is grasses, sedges, and ferns found in and around their scrub covered refuges. They are distinguished by a reddish tinge to the mostly grey fur and a distinct stripe at the cheek. They move with great speed and agility when observed, with a forward leaning posture and a bushy tail that arches over the back.

==Etymology==
The name comes from the [[Bininj Kunwok language|Kunwinjku]] language of West [[Arnhem Land]].<ref>{{cite web |last1=Garde |first1=Murray |title=nabarlek |url=https://www.njamed.com/#nabarlek |website=Bininj Kunwok Online Dictionary |publisher=Bininj Kunwok Regional Language Centre |access-date=29 May 2019}}</ref> The animal has also lent its name to the music rock group from the area, [[Nabarlek (band)|Nabarlek]]{{fact|date=April 2024}} and [[Gwendolyne Stevens]]' [[Nabarlek Uranium Mine|uranium mine]].<ref>{{Cite news |date=1970-09-02 |title=Woman has uranium rights |url=http://nla.gov.au/nla.news-article110458605 |access-date=2024-04-16 |work=Canberra Times}}</ref>

==Taxonomy ==
[[John Gould]] presented a description of this species to the  [[Zoological Society of London]] in 1842, which was published in its ''Proceedings'' and introduced by the presiding chair [[William Yarrell]] as "two new species of Kangaroo".<ref name="Gould1842" /><ref name="MSW" /> The affinities of the species have been recognised in several ways, including an arrangement that sees it placed with the {{'}}''brachyotis'' species group'. Other authors had separated this species to a new genus ''Peradorcas'', producing a new combination '''''Peradorcas concinna''''', although the revision by [[D. J. Kitchener]] of ''Petrogale'' did not recognise this treatment and this is maintained by other authorities. The locality of the type specimen is [[Wyndham, Western Australia]].<ref name=MSW/> The specimen was collected and brought to England on the voyage of {{HMS|Beagle}}.<ref name="Gould1842" />

Nabarlek is most closely related to the monjon and to the short-eared rock-wallaby ''[[Petrogale brachyotis]]''.{{Citation needed|date=March 2019}} It was formerly considered distinct enough to be assigned its own genus, ''Peradorcas'' but it is now considered to belong, like the rest of the rock-wallabies, in the genus ''[[Petrogale]]''.<ref name=MSW/>

The common name designated for a similar species, [[monjon]] for ''P. burbidgei'', is also used to refer this species in the Kimberley region; the two species are however known to be distinct by the indigenous people from whose language the name derives.<ref name="Burbidge1990" /> Common names for the species include the  '''little rock-wallaby'''<ref name="Menkhorst2011" /><ref name="Sanson1983" /> or '''pygmy rock-wallaby'''.

===Subspecies===
Three subspecies have been recognised:<ref name="AFD" />

* ''P. concinna concinna'' Gould, 1842 
The nominate subspecies, found at the [[Top End]], follows Gould's original description.
* ''P. concinna canescens'' Thomas, 1909 
The [[Arnhem Land]] population.
The description for this subspecies was published by [[Oldfield Thomas]] after examination of new specimens that confirmed morphological distinctions in different localities. The type specimen, already held at the British Museum, was collected in 1902 by [[J. T. Tunney]]; he had killed this animal at Nellie Creek.<ref name="Thomas1909" />
* ''P. concinna monastria'' (Thomas, 1926)
A subspecies restricted to the [[Kimberley (Western Australia)|Kimberley]] region.

==Description==
A species of ''[[Petrogale]]'', the rock wallabies, distinguished by its small size. The [[pelage]] is a grey colour, with reddish highlights at the fore-arm, legs and hind parts. The tail is also reddish grey, with a bushy end  of coarser hair that begins two thirds along its length, the total length may be from 260 to 335 millimetres. 
The cheek is marked with a whitish stripe from the eye to the nostrils,  a lighter tone that contrasts with the blackish parts of the snout. Another darker stripe is found below the eye and down the neck, the region beneath the fore-arm is also blackish.
The head and body length combined in 310 to 365&nbsp;mm, the smallest of the genus but for ''P. burbidgei''. The measurement of the hindfoot is 95 to 105&nbsp;mm, the ear from base to tip is 41 to 45&nbsp;mm. The weight range is from 1.2 to 1.6 kilograms.<ref name="Menkhorst2011" />

The dentition of ''P. cocinna'' is unique amongst the marsupial species, with the supernumerary molars being continually replaced. These teeth emerge in a regular size and shape, with each row containing four to six molars and another that is yet to erupt. The early loss of the premolar appears to allow this regeneration to continue throughout their life.<ref name="Sanson1983" />

Nabarlek is often found with the similar ''P. brachyotis'', whose coloration is more variable, and a young individual may be indistinguishable from this species in field observations.<ref name="Churchill1997" />

==Behaviour==
Nabarlek move quickly with a distinctive horizontal posture, the tail curled toward the middle of the back with raised hairs in the tufty end. The species has a timid disposition, although is somewhat gregarious in associations with others. Their feeding and other activities is usually nocturnal, and they may range beyond their refuge to forage.

The species will range several hundred metres from its secure position, foraging in the surrounding black soil terrain, this contrasts with the less venturous behaviour of the short-eared ''P. brachyotis''.<ref name="Sanson1983" />

The discrete and cautious nature of narbarlek makes capture of specimens difficult, they are regarded as 'trap-shy' in attempts to survey their population.<ref name="Churchill1997" />

==Diet==
The diet includes a variety of plants, including grasses, ferns and sedges.<ref name="Menkhorst2011" /> The plants consumed in Arnhem land during the wet season are the grass species of ''[[Eriachne]]'' and the sedges ''[[Cyperus cuspidatus]]'' and species of ''[[Fimbristylis]]'', which occur in soils above the flood levels. The change in season has the species seek shelter during the day in sandstone formations and forage at local [[billabong]]s for a fern species ''[[Marsilea crenata]]''.

The high percentage of silica in its diet, 15 to 25% in some foliage, was proposed to have favoured the continual regeneration of molars.<ref name="Sanson1983" /> Attempts to locate the high silica fern in later surveys have not recorded  ''Marsilea crenata'' at any sites, and the complex relationship between diet and dentition remains to be examined.<ref name="Churchill1997" />

==Distribution and habitat==
The nabarlek is found in three distinct and geographically remote populations, one in [[Arnhem Land]] which includes [[Groote Eylandt]], a larger island in the [[Gulf of Carpentaria]], and another population between the [[Mary River (Northern Territory)|Mary]] and [[Victoria River (Northern Territory)|Victoria]] Rivers at the [[Top End]] of the continent. The population in the northwest [[Kimberley (Western Australia)|Kimberley]] region is confined to the coastal areas and on some of the islands in the [[Bonaparte Archipelago]], these are Borda, Long, Hidden and [[Augustus Island (Western Australia)|Augustus Island]]s.<ref name="Menkhorst2011" />

The habitat is usually scrubby vegetation over sandstone formations, granitic outcrops, breakaways of laterite, boulder piles and rocky slopes.<ref name="Menkhorst2011" />

==Conservation==
It is classified as [[Endangered]] by the [[IUCN]].

==References==
{{Reflist|2|refs=
<ref name="AFD">{{cite web |title=''Petrogale concinna'' Gould, 1842complete |url=https://biodiversity.org.au/afd/taxa/Petrogale_concinna;Petrogale/complete |website=[[Australian Faunal Directory]] |access-date=7 March 2019 |language=en}}</ref>
<ref name="Burbidge1990">{{cite journal |last1=Burbidge |first1=Andrew A. |last2=Fuller |first2=Phillip J. |title=On the vernacular name of ''Petrogale burbidgei'' |journal=Records of the Western Australian Museum |date=1990 |volume=14 |issue=4 |pages=645–646 |url=https://www.biodiversitylibrary.org/part/237757}}</ref>
<ref name="Churchill1997">{{cite journal |last1=Churchill |first1=S. |title=Habitat use, Distribution and Conservation Status of the Nabarlek, ''Petrogale concinna'', and sympatric rock-dwelling mammals, in the Northern Territory. |journal=Australian Mammalogy |date=1997 |volume=19 |issue=2 |pages=297–308 |doi=10.1071/AM97297 |url=https://www.researchgate.net/publication/323644049}}</ref>
<ref name="Gould1842">{{cite journal |last1=Gould |first1=J. |title=On a New Species of ''Petrogale — P. concinna'' |journal=Proceedings of the Zoological Society of London |date=1842 |volume=1842 |page=57 |url=https://biodiversitylibrary.org/page/30679819 |publisher=Academic Press, [etc.]}}</ref>
<ref name="Menkhorst2011">{{cite book |last1=Menkhorst |first1=P.W. |last2=Knight |first2=F. |author-link1=Peter Menkhorst |author2-link=Frank Knight |title=A field guide to the mammals of Australia |date=2011 |publisher=Oxford University Press |location=Melbourne |isbn=9780195573954 |page=208 |edition=3rd}}</ref>
<ref name="MSW">{{MSW3 Diprotodontia|id=11000282}}</ref>
<ref name="Sanson1983">{{cite encyclopedia |last = Sanson |first = G.D. |author-link =  G.D. Sanson |editor-last = Strahan |editor-first = R. |editor-link = Ronald Strahan |encyclopedia = Complete book of Australian mammals. [[National Photographic Index of Australian Wildlife|The national photographic index of Australian wildlife]] |title = Nabarlek ''Petrogale cocinna''|trans-title =  |language =  |edition = 1 |year = 1983 |publisher = Angus & Robertson |series =  |location = London |isbn = 0207144540 |pages = 291–293}}</ref>
<ref name="Thomas1909">{{cite journal |last1=Thomas |first1=O. |title=Two new mammals from N. Australia |journal=The Annals and Magazine of Natural History; Zoology, Botany, and Geology |date=1909 |volume=4 |issue=21 |series=8 |pages=197–198 |url=https://biodiversitylibrary.org/page/22097576|doi=10.1080/00222930908692661 }}</ref>

}}

==External links==
{{Commons category|Petrogale concinna}}
{{Wikispecies|Petrogale concinna}}

* [https://web.archive.org/web/20060914025420/http://www.nt.gov.au/nreta/wildlife/threatened/pdf/nabarlek_nt.pdf Threatened Species of the Northern Territory]

{{Diprotodontia|M.}}
{{Taxonbar|from=Q209591}}

[[Category:Macropods]]
[[Category:Mammals of Western Australia]]
[[Category:Mammals of the Northern Territory]]
[[Category:Marsupials of Australia]]
[[Category:Mammals described in 1842]]
[[Category:Taxa named by John Gould]]