Petrogale purpureicollis, Le Souef, 1924

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 : 715

34.

Purple-necked Rock Wallaby

Petrogale purpureicollis

French: Wallaby violacé / German: Purpurnacken-Felskanguru / Spanish: Ualabi rupestre de cuello purpura

Other common names: Purple-necked Rock-wallaby

Taxonomy. Petrogale purpureicollis Le Souef, 1924 ,

Dajarra , north-western Queensland, Australia.

A memberof the lateralis / penicillata group of species (which includes also P. rothschildi , P. lateralis , P. penicillata , P. herbert, P. inornata , P assimilis , P. sharmani , P mareeba , P. godmani , P. coenensis ). Formerly regarded as a subspecies of P. lateralis or P. perucillata, and earlier of P. inornata , but reinstated as a full species in 2001. Monotypic.

Distribution. N Australia, patchily distributed from Mt Isa and Cloncurry SE to Winton and NW to beyond Boodjamulla National Park (= Lawn Hill National Park), in NW Queensland. N and W limits uncertain; may extend into Northern Territory.

Descriptive notes. Head-body 38.9-60.9 cm (males) and 46.5-55.2 cm (females), tail 48.8-58 cm (males) and 44.5-53.8 cm (females); weight 3.3-7.1 kg (males) and 2.7-5.7 kg (females). Light brown with darker guard hairs across back and rump, paler on chest and belly. Gray between ears, on neck, and across shoulders. Often light rufous on rump and at base oftail. Muzzle black, pale cheek stripe; dark brown dorsalstripe on face from between eyes to between ears. Characteristic purple-red pigmentation over face, head, throat, neck, and sometimes upper chest and shoulders; intensity of pigmentation varies individually and seasonally, from faint pink wash to rich red/purple, and often most intense on cheeks, around eyes, and at base of ears. Back of ears grades to dark or rufous brown at tips. Arms and legs similar in color to body, but digits dark brown. Axillary patch dark brown; occasionally, dark brown markings from axillary patch to thigh, but no distinctside stripe. Fur short but dense and very soft. Tail lighter than body, distal third dark,slight dark terminal brush. Pelage more orange in summer and grayer in winter. Diploid chromosome numberis 22.

Habitat. Rocky outcrops, boulder piles, rocky slopes, cliffs, and gorges in limestone, sandstone, and quartzite formations associated with dry open eucalypt ( Eucalyptus , Myrtaceae ) or acacia ( Acacia , Fabaceae ) woodland, typically with spinifex (7riodia, Poaceae ) grassland understory.

Food and Feeding. Poorly known. Observed to eat grass and browse. Captive animals occasionally consumed birds, rodents, and gastropods. Wateris obtained by drinking or from moisture in herbage and dew. Many large colonies have access to semi-permanent freshwater, and populations at othersites can die out during extended droughts.

Breeding. Females reach sexual maturity from 18 months and males from 22 months. Females are continuous breeders, producing one young per pregnancy. Females exhibit embryonic diapause and post-partum estrus, usually mating within 48 hours of giving birth. The estrous cycle is 36-38 (mean 37) days and gestation 33-35 (mean 34) days. Young spends 6-7 months in the pouch and then accompanies the mother as a young-at-foot until after weaning, at 9-12 months.

Activity patterns. Largely nocturnal in summer, crepuscular or partially diurnal in other months. Shelters during day among rocks or within boulder piles. In cooler months, sits in regular sites on rocks to bask in the sun in early morning and sometimes in afternoon. Moves off rocks in late afternoon or evening to feed in surrounding woodland.

Movements, Home range and Social organization. Poorly known. Typically found living in small groups, although more than 20 individuals have been found at somesites. In captivity, both males and females were intolerant of same-sex individuals.

Status and Conservation. Classified as Least Concern on The IUCN Red List. This rock wallaby is common around Mount Isa, Cloncurry, and Dajarra, but is much rarer to the north-west around Lawn Hill and has declined in south-east around Winton, with some local population extinctions. Threats include habitat degradation caused by domestic and feral herbivores (e.g. cattle, horses, goats) and potentially altered fire regimes; introduced predators are potentially an additional threat. Additional research on distribution, general ecology, and the impact of threats is required.

Bibliography. Eldridge (1997 2012b), Eldridge, Browning & Close (2001), Eldridge, Johnson et al. (1993), Johnson (2003), Johnson & Delean (2002b), Johnson & Eldridge (2008b), Johnson et al. (2001), Le Souef (1924), McKnight (2008f), Potter, Cooper et al. (2012), Sharman et al. (1989), Woinarski et al. (2014ay).

Figures

34. Purple-necked Rock Wallaby (Petrogale purpureicollis), 35. Brush-tailed Rock Wallaby (Petrogale penicillata)

Distribution. N Australia, patchily distributed from Mt Isa and Cloncurry SE to Winton and NW to beyond Boodjamulla National Park (= Lawn Hill National Park), in NW Queensland. N and W limits uncertain; may extend into Northern Territory.