Petrogale wilkinsi, Thomas, 1926

Russell A. Mittermeier & Don E. Wilson, 2015, Macropodidae, Handbook of the Mammals of the World – Volume 5 Monotremes and Marsupials, Barcelona: Lynx Edicions, pp. 630-735 : 709

27.

Wilkins’s Rock Wallaby

Petrogale wilkinsi

French: Wallaby de Wilkins / German: Wilkins-Felskanguru / Spanish: Ualabi rupestre de Wilkins

Other common names: Eastern Short-eared Rock Wallaby

Taxonomy. Petrogale wilkinsi Thomas, 1926 ,

Roper River , south-eastern Arnhem Land, Northern Territory, Australia.

A member of the brachyotis species group which also includes P. wilkinsi , P. burbidger, and P. concinna . Formerly placed within P. brachyotis , but reinstated as a separate species in 2014. Preliminary data suggest that populations from Groote Eylandt (previously described as P. longmani) and the southern Gulf of Carpentaria are both morphologically and genetically distinct, and may represent subspecies; further research required. Monotypic.

Distribution. N Australia from Daly River, in W Northern Territory, E throughout the Top End to Wollogorang, near Northern Territory-Queensland border; also Groote Eylandt, Bickerton I, the Sir Edward Pellew Group, and Wessel and English Company Island Groups. E limit uncertain; may extend into NW Queensland.

Descriptive notes. Head-body 37.5-57 cm (males) and 31-47.3 cm (females), tail 31.2-51.7 cm (males) and 29.7-52 cm (females); weight 2.5-2 kg (males) and 1.8-2 kg (females). Dark gray to graybrown dorsally, paler to white ventrally. Distinct dark brown to black mid-dorsal stripe from forehead to beyond shoulders. Prominent white shoulder stripe behind well-developed dark axillary patch. Pale side stripe and hip stripe. Limbs brightly colored from yellow to reddish-brown. Face light brown to orange-brown. Ears less than half length of head and uniformly colored. Tail lighter than body dorsally, darkens (brown to black) distally, with slight terminal brush in some specimens. Specimens from Roper River are overall more yellowish, while those from Groote Eylandt are darker silvery gray; individuals from southern Gulf of Carpentaria are lighter brown and less distinctly marked. Diploid chromosome number is 18.

Habitat. Rockyhills, slopes and outcrops, boulderpiles,cliffs, gorges, and escarpments in savanna woodland and monsoon rainforest.

Food and Feeding. Feeds predominantly on browse and forbs, but variable proportions of grass consumed across its range. Significantly more grass eaten when more is available (in wet season). Seeds and fruit from a variety of species are also consumed. Reported by Aboriginal people to eat native yams ( Dioscorea transversa , Dioscoreaceae ).

Breeding. Poorly known. Females produce a single young and appear to breed continuously.

Activity patterns. Shelters during day in caves and crevices, among rocks, or within boulder piles. Largely nocturnal in summer, crepuscular or partially diurnal in other months. In cooler months may sit on rocks to bask in sun, especially in morning or late afternoon. Moves off the rocks in late afternoon or early evening to feed.

Movements, Home range and Social organization. Individuals move up to 480 m from rocks to feed in adjacent woodlands. Average home range (100% minimum convex polygon) during dry season is 17 ha, with no difference between the sexes, although ranges likely to be smaller in wet season. Home ranges overlap extensively (at least 38%) with those of others (of both sexes). Individuals use up to seven daytime dens within their home range. A den site may be utilized by multiple individuals, and concurrent use of dens is common, but never by more than one male. Genetic data suggest that females are highly philopatric and dispersal is male-biased. Limited contemporary and historic gene flow is evident beyond 1-2 km for females and 4 km for males, even in intact landscapes.

Status and Conservation. Classified as Least Concern on The IUCN Red List (under P. brachyotis ). Wilkins’s Rock Wallaby is currently common throughout most ofits distribution and occurs in several protected areas. In the long term it may be threatened by habitat degradation as a consequence of cattle grazing and altered fire regimes. Additional research on ecology and on the impact of potential threats is required.

Bibliography. Eldridge (1997), Eldridge & Telfer (2008), Pearson (2012), Potter, Close et al. (2014), Potter, Cooper et al. (2012), Sanson, Nelson & Fell (1985), Sharman et al. (1989), Telfer & Bowman (2006), Telfer & Eldridge (2010), Telfer & Garde (2006), Telfer & Griffiths (2006), Telfer et al. (2008), Woinarski, Palmer et al. (1999), Woinarski, Telfer & Burbidge (2008).

Figures

On following pages: 29. Monjon (Petrogale burbidgel); 30. Proserpine Rock Wallaby (Petrogale persephone); 31. Yellow-footed Rock Wallaby (Petrogale xanthopus); 32. Rothschilds Rock Wallaby (Petrogale rothschild); 33. Black- footed Rock Wallaby (Petrogale lateralis).

Distribution. N Australia from Daly River, in W Northern Territory, E throughout the Top End to Wollogorang, near Northern Territory-Queensland border; also Groote Eylandt, Bickerton I, the Sir Edward Pellew Group, and Wessel and English Company Island Groups. E limit uncertain; may extend into NW Queensland.