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 genus Macropus includes not only the large kangaroos but a range of mid-sized macropods known collectively at wallabies or brush wallabies. The exception is the Swamp Wallaby which is in its own genus Wallabia by virtue of its different chromosome number and other features. With the advent of agriculture and pastoralism the wallabies have fared less well than the kangaroos with most species in reduced ranges since European settlement. One species, the Toolache Wallaby (Macropus greyi) is extinct. In this pattern of range contraction, the Swamp Wallaby, is again an exception as it remains reasonably abundant in many peri-urban parks and reserves.
The Wallabies like the larger Kangaroos are predominantly grazers but may take some browse, especially the Swamp Wallaby. They share a similar body form and habits to the larger Kangaroos and are sympatric with Grey Kangaroos or the Antilopine Wallaroo in the north.
Red-necked Wallaby (Mainland)
Macropus rufogriseus banksianus
Warrumbungle National Park, New South Wales
Warrumbungle National Park is on the western margin of the Red-necked Wallaby's range but is an exceptionally good place to see well-habituated wallabies co-habiting with equally habituated Eastern Grey Kangaroos who will share your campground. The Park has spectacular scenery resulting from ancient volcanic remnants forming ridges, spires and domes intersected by deep gorges. The Park has a number of well-dispersed campgrounds with good facilities and overnight accommodation for small to medium-sized groups. Other accommodation is found in nearby Coonabarabran (35 km away).
The Red-necked Wallaby occupies a wide range of habitats but does not travel far from some form of dense cover like tall tussock grasses, shrubs and the shrubby understorey of woodland and forest. However, they range out into clear pasture and grassland from this cover to forage. Along the east coast of Australia, it is present in a broad gradient of habitat and shares this generalist characteristic with the Swamp Wallaby. The two species are largely separated by the former's preference for the ecotone between dense and open vegetation and the latter's preference for dense vegetation. The Red-necked Wallaby frequently shares habitat with the larger Eastern Grey Kangaroo but a study in Victoria showed that the two species rarely associate while foraging.
Predominantly grazers with some forbs (herbs), browse and the young shoots and leaves of heath-land plants in the diet. The diet of the Tasmanian sub-species is better studied.
The reproductive biology of the Red-necked Wallaby is typical of the patterns found in the Brush Wallabies. The gestation period is about 30 d and oestrus is post-partum. Pouch life is 9 months. Breeding is aseasonal on the mainland but seasonal in the Tasmanian sub-species.
The mother-young relationship has been particularly well studied in a free-living population in north-eastern NSW. Red-necked Wallabies provided the first evidence of kinship shaping the relationships between females. Female offspring settle within their mother's home-ranges whereas males have usually dispersed elsewhere by two years of age. However, until dispersal the relationship with a son is closer than that with a daughter after weaning. Allowing either sons or daughters to remain in the mother's range reduces her chance of reproducing successfully again. Thus matrilines (lineages of female relatives) build up and the population becomes self-regulating amongst females and fewer sons will be produced as an individual's reproductive success is suppressed (note it still has a genetic investment in its relatives) by competition from female kin.
The lesson we can learn from the Red-necked Wallaby and one which seems to be shared with a number of other macropod species living in the more predictable temperate and tropical climates, is that populations move to an equilibrium with their resources and self-regulate. When these populations are perturbed by lethal control measures the brakes are released from reproduction and recruitment may accelerate. Likewise if resources are improved with fertilisers and irrigation/watering, the accelerator may be depressed for a time before a new equilibrium is reached.
F When you see an aggregation of Red-necked Wallabies the females are likely to be relatives. If there are young-at-foot or juveniles about the see if sons or daughters are more favoured. This may be a challenge as Red-necked Wallabies are one of the 'hider' species amongst the macropods. The hider strategy is to keep the young-at-foot hidden in denser vegetation like large grass tussocks and the return regularly to them to suckle. The alternate 'follower' strategy employs by the large kangaroos and most other wallabies is for the young-at-foot to follow the mother throughout the day. However, even the latter group may 'park' their young-at-foot when going into water to drink.
The Red-necked Wallaby expresses a matrilineal relationship in the females but is not particularly gregarious. Thus the female kin may be well spaced out even though they share a home range. Even so mothers and their sub-adult sons and daughters and adult female relatives are frequent associates. Individuals resting in cover are usually on their own but small groups may form in open foraging habitat. These aggregations are typically much smaller than those of sympatric Whiptail Wallabies or Eastern Grey Kangaroos.
Individuals range over greater areas in winter than in the warmer months when grass growth is favoured. Female home ranges overlap and those of large males encompass several females. Medium-sized males tend to occupy ranges to the periphery of the main population. Females shift their home ranges closer to dense cover as their pouch young emerge consistent with their hider strategy.
A frequent interaction amongst males is bouts of sparring. This behaviour takes the form of play-fighting and serves to exercise fighting skills in a typically non-damaging interactions. Individuals may also learn to assess the abilities of others and potentially avoid damaging fights over resources, especially mating opportunities. Larger males may self-handicap to prolong interactions with smaller individuals; e.g. stand flat-footed rather than on their toes. This is not necessarily altruistic as they still test the skills of an emerging rival.
Coulson G (1999) Monospecific and Heterospecific Grouping and Feeding Behavior in Grey Kangaroos and Red-Necked Wallabies. Journal of Mammalogy 80, 270-282.
Johnson CN (1986) Philopatry, reproductive success of females, and maternal investment in the red-necked wallaby. Behavioral Ecology and Sociobiology 19, 143-150.
Johnson CN (1987) Macropod studies at Wallaby Creek. V. Home range and movements of the red-necked wallaby. Australian Wildlife Research 14, 125-137.
Southwell CJ, Cairns SC, Pople AR, Delaney R (1999) Gradient analysis of macropod distribution in open forest and woodland of eastern Australia. Australian Journal Of Ecology 24, 132-143.
Watson DM (1998) Kangaroos at play: play behaviour in the Macropodoidea. In 'Animal Play: Evolutionary, Comparative and Ecological Perspectives'. (Eds M Bekoff and JA Byers) pp. 45-98. (Cambridge University Press: Cambridge)