General information
Kangaroos are marsupials and belong to the Family Macropodidae (i.e. big feet) that is grouped with the Potoroidae (potoroos, bettongs, rat-kangaroos) and Hypsiprymnodontidae (musky rat-kangaroo) in the Super-Family, Macropodoidea. This comprises around 50 species in
The Rock-wallabies (Petrogale spp.) is the most diverse genus amongst the living macropods with 16 species ranging from 1 to 12 kg in size. They are found across mainland Australia and on some recently separated offshore islands but not on the Bass Strait Islands, Tasmania or New Guinea. The species diversified from a common ancestor about 4 million years ago and their closest affinity to other macropods is with the Tree-kangaroos. Diversification of species occurred in two waves. The first gave rise to the Short-eared Rock-wallaby, the Monjon, the Narbelek, the Yellow-footed Rock-Wallaby and the Proserpine Rock-wallaby. The second was about a million years ago and lead to species that are not all morphologically distinctive like those along the Queensland seaboard. All Rock-wallabies favour habitat with rocky outcrops and slopes, cliffs and gorges or are found on boulder piles and escarpments especially in the wet-dry tropics. Their ability to scale precipitous rock faces in leaps that appear to defy gravity comes from adaptations to the feet and tail. The feet are short relative to the majority of macropods that inhabit flat ground. The pads are thick, spongy and highly granulated so that they compress on the rock surface and maximise grip. The tail is long and cylindrical with little taper and great flexibility. The tail acts as a counterbalance and rudder in rapid hopping across uneven surfaces and allows changes of direction in mid-air.
Species
Short-eared Rock-wallaby
Petrogale brachyotis ('short-eared rock-weasel')
Best place to see
Litchfield National Park, Northern Territory
Litchfield National Park is within a 2-hour drive from Darwin along a sealed (bituminised road). The Park has many attractions including its waterfalls and natural plunge pools, abundant fauna, rich woodland flora communities including pockets of monsoon forest, and the unusual magnetic termite mounds. The park has a number of rocky outcrops and some escarpments. Waterfalls cascade over the latter and provide popular swimming holes at their base. It is amongst the rock outcrops and steeper faces of the escarpments that you are most likely to see the Short-eared Rock-wallaby. They may share habitat with the Northern Wallaroo which will be larger and more often on the gentler slopes and rock piles. The Park is also nominated as the best place to see the Northern Wallaroo and Antilopine Wallaroo, and Agile Wallabies are abundant.
Identification
Males average 4.4 kg and range up to 5.6 kg and females average 3.7 kg and range up to 4.7 kg. The Short-eared Rock-wallaby is widespread and populations from different geographical areas vary markedly in size and body colour. The Northern Territory populations tend to be more brightly coloured, especially from the escarpment of Arnhem land, than the Kimberley populations. In the NT, the back of Short-eared Rock-wallabies is a grizzled dark-grey brown formed from hairs that have a mid-grey base, a white centre and a black tip. The throat and chin are pale yellow-white, and the chest and belly grey-yellow. The individual hairs have a mid-grey base and the remainder is pale yellowi-brown. The face is a yellow-brown, and has a pale yellow-brown stripe from the upper lip below the eye to the base of the ear. The ears follow the colour of the face and there are sparse, pale yellow hairs inside. The crest of the head has a dark dorsal stripe from between the eyes over to the shoulders. The nose is black and the rhinarium naked. The shoulders are defined by a dark-brown to black patch to the posterior marked by a pale yellow-white stripe. There is a poorly developed, pale hip stripe. The fore legs are yellow-brown and darken to grey-black fur at the fingers. The hind legs and feet are yellow-brown like the fore legs but the toes are darker and defined by more black hairs. The base of the tail is yellow-brown and darkens towards the tip. The distal third of the tail is almost black and the hairs on longer forming a pronounced brush. Rare individuals have a short white tip to the tail.
Habitat
To be added
Foraging behaviour
To be added
Reproductive behaviour
To be added
Social organisation
To be added
Further readings
Campeau-Peloquin A, Kirsch JAW, Eldridge MDB, Lapointe FJ (2001) Phylogeny of the rock-wallabies, Petrogale (Marsupialia: Macropodidae) based on DNA/DNA hybridisation. Australian Journal Of Zoology 49, 463-486.
Pearson DJ, Kinnear JE (1997) A review of the distribution, status and conservation of rock-wallabies in Western Australia. Australian Mammalogy 19, 137-152.
Telfer WR, Bowman MJS (2006) Diet of four rock-dwelling macropods in the Australian monsoon tropics. Austral Ecology 31, 817-827.
Telfer WR, Griffiths AD (2006) Dry-season use of space, habitats and shelters by the short-eared rock-wallaby (Petrogale brachyotis) in the monsoon tropics. Wildlife Research 33, 207.214.