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
Two of the four species of Hare-wallabies that were identified at European colonisation of Australia are extinct. The only species which retains a broad geographic range is the Spectacled Hare-wallaby which also has a small population is southern New Guinea. The genus was once common in the deserts and tropics and south-west of Western Australia. Pastoralism and the introduction of livestock grazing and concomitant changes in fire management and release of rabbits, foxes and cats have wrought a devastating impacts on the attractive small wallabies. A characteristic, emphasised in the Spectacled Hare-wallaby, is the rufous fur around the eye. The Hare-wallabies have long feet with long claws but the fore-limbs are very delicate and short.
Species
Mala (Rufous Hare-wallaby)
Lagochetes hirsutus hirsutus ('shaggy hare dancer')
Best place to see
Tanami Desert, Northern Territory
The Tanami Track starts 643 km north of Alice Springs. The desert is a very remote and potentially hostile location and travellers should not enter without a very well-equipped 4-wheel drive vehicle or with an experienced tour operator. Fuel and refreshments are available at Tilmouth Well, Yuendumu and Rabbit Flat. The Tanami Desert was the last refuge of the mainland subspecies of the Mala and individuals were caught and taken to Alice Springs for a captive breeding program. Attempts at reintroduction have largely been unsuccessful. The Tanami now has a large reserve, Newhaven, of 262,600 ha run by Birds Australia. The Reserve secures habitat for the Night Parrot and some other nationally threatened bird species. In addition, there are threatened species of mammals including the Mulgara (a marsupial carnivore), the Marsupial Mole, the Black-footed Rock-wallaby and potentially the Bilby and Mala.
Identification
Habitat
The Mala was once widespread in the arid regions of Central and Western Australia in spinifex (Triodia pungens) grasslands. Its range in Western Australia extended into peripheral shrublands on sandplains which became parts of the current pastoral and wheatbelt zones. Information on habitat selection was gained from remnant populations in the Tanami Desert before these went extinct from predation by foxes and wildfire in the 1980s and early 1990s. The study site comprised a spinifex sandplain, dominated by Triodia pungens and Plectrachne schinzii, interspersed with low caliche (hardened deposit of calcium carbonate) areas characterised by sandy clay soils heavily impregnated with salt and dominated by halophytic (salt-tolerant) grasses and subshrubs (e.g. Neobassia astrocarpa). Mala used both the Triodia dominated dunes and the Plectrachne dominated dune faces extending out into the caliche/salt-pan. The boundary (ecotone) between the two vegetation/landscape types was favoured with Mala ranging further onto the pans in dry periods. The Mala preferred areas of patchy, widely spaced broad spinifex hummocks interspersed with perennial grasses and other food plants. The spinifex hummocks presumably provided cover and protection from predators and inclement weather. Fire likely plays a key role in preventing the spinifex from dominating the landscape and closing out food species. Even so a balance needs to be maintained by the closed and protective cover and the more open foraging areas and thus Mala favour the ecotone between the two.
Foraging behaviour
The diet of the Mala in the Tanami Desert showed some flexibility in this species. Perennial grasses are a persistent component of the diet through the run of seasons. When available grass seeds and the seeds and bulbs of sedges are eaten. Mala do not restrict themselves to monocots but eat some dicots in small proportions. During dry periods their diet broadened to include insect and fibrous plants like spinifex and the subshrubs. The Mala has a large, tubiform forestomach like the large kangaroos. This relatively large gut along with a low maintenance energy requirement enables the Mala to survive on a fibrous, poor-quality diet atypical of other mammalian herbivores of its diminutive size.
Reproductive behaviour
The Mala has a short gestation period and pouch live is on average 124 days. This allows for the production of up to three young in a year with continuous breeding. In the wild, one or two young per year are most likely. Embryonic diapause is found and there is no seasonality in breeding provided conditions sustain lactation in females. However, in the Tanami Desert pouch young were more likely in the wet season (December-July). Sexual maturity in females occurs within their first year and in the second year for males. Even so the species is not sexually dimorphic and the later maturity of males is not a function of attaining a larger body size. The sex ratio of pouch young is near parity (1:1) but dispersal in males may lead to higher mortality and a female bias in the adult population.
Most observations on the behaviour of Mala have been made in captive colonies housed in Alice Springs. Females were generally tolerant of each other but occupy individual squats (shallow depressions the Mala digs out) under tussock grasses. Male-male interactions were brief and included fights including pawing, cuffing and kicks from the side or while airborne, and chases. The most intense aggression, leading to severe injury in closed captive groups, was between adults and juveniles suggesting there may be forced dispersal of the latter in the wild.
Male-female interactions were common and typical of macropods small and large. Males checked the reproductive status of females early in the evening by sniffing at the pouch and cloaca. Females reacted by moving away or falling on their side and kicking out with their hindfeet at the male if unresponsive. Males attempted mountings from the rear and if the female moved away or kicked (from the side) at them they often continued to pursue the female while emitting loud repetitive clicking vocalistions.
Social organisation
Mala are nocturnal emerging from their squats under tussocks in the evening and returning before dawn. They use several squats which are only shared by females and their dependent offspring (young-at-foot). Male home ranges are larger than those of females and overlap several females from observations in large enclosures and post-release data for reintroductions (e.g. to Francois Peron National Park). Captive observations suggest a degree of hierarchical organisation in both females and males in terms of access to resources. However, whether this is an artefact of captivity or exists in wild populations remains to be determined. There is likely a degree of competition both within and between sexes but with the broad diet of Mala and the presumed abundance of shelter sites, it is likely than most competition is amongst males for access to oestrous females. The lack of pronounced sexual dimorphism suggests that this in by opportunity and persistence rather than morphological advantage.
Further readings
Bridie A, Hume ID, Hill DM (1994) Digestive-tract function and energy requirements of the Rufous Hare-Wallaby, Lagorchestes hirsutus. Australian Journal of Zoology 42, 761-774.
Lundie-Jenkins G (1993a) Ecology of the rufous hare-wallaby Lagorchestes hirsutus Gould (Marsupialia: Macropodidae), in the Tanami Desert, Northern Territory. I. Patterns of habitat use. Wildlife Research 20, 457-476.
Lundie-Jenkins G (1993b) Observations on the behaviour of the rufous hare-wallaby, Lagorchestes hirsutus Gould (Marsupialia: Macropodidae) in captivity. Australian Mammalogy 16, 29-34.
Lundie-Jenkins G, Phillips CM, Jarman PJ (1993) Ecology of the rufous hare-wallaby, Lagorchestes hirsutus Gould (Marsupialia: Macropodidae) in the Tanami Desert, Northern Territory. II. Diet and feeding strategy. Wildlife Research 20, 477-494.