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 species commonly called the ‘kangaroos’ are the result of an arbitrary division of the Macropodidae based on a hind foot longer than 250 mm. The kangaroos then comprise six species of which the best known are the Red Kangaroo (Macropus rufus) of the arid heartland and the Eastern Grey Kangaroo (M. giganteus), the latter being Skippy's species. The Eastern Grey Kangaroo has a broad latitudinal distribution up the eastern part of Australia from northern Tasmania to Cape York. Its close relative, the Western Grey Kangaroo (M. fuliginosus) has a southerly and westerly distribution form western NSW and Victoria through South Australia to Western Australia. The Common Wallaroo has the broadest geographic distribuion of the kangaroos and forms a cline of subspecies across the continent but wallaroos are not found in Tasmania. The remaining two kangaroo species are less well-known and include the Antilopine Wallaroo (M. antilopinus) from the
Macropus robustus robustus ('robust long-foot')
Lark Quarry Conservation Park, Queensland
Eastern Wallaroos are distributed up the east coast of Australia and are locally abundant in many parts of the Great Dividing Range and foothills. For example, they are readily seen in the high country of Victoria, the Monaro, Blue Mountains and New England regions of NSW, and various ranges in south-western Queensland. Thus Lark Quarry Conservation Park in mid-western Queensland (110 km south-west of Winton) is an out of the way destination for the 'best-place-to-see' and a point of intergradation between Eastern Wallaroos and Euros. Even so the species is particularly common an easy to see in this Park and there is an added bonus of viewing the tracks of stampeding dinosaurs. The Park has spectacular outback scenery of mesas, escarpments and gullies known as jump-up country in Outback vernacular. Geologists refer to these as 'dissected residuals' which represent the less erodable parts of ancient lakes and seas. The dominant vegetation is spinifex which can be utilised by the Common Wallaroo due to their low nitrogen requirement. The Park currently does not have camping and is a remote destination. For tourism information go to www.experiencewinton.com.au and specific information on the dinosaur tracks go to www.dinosaurtrackways.com.au. We expect some arguments about the best place to see the Eastern Wallaroo so send you recommendation (and justification) through the feedback page.The Eastern Wallaroo is the temperate eastern sub-species of the most widespread kangaroo, the Common Wallaroo (or Hill Kangaroo). Eastern Wallaroos have a large naked rhinarium giving them a dark shiny ‘button nose’ like koalas and wombats. They have no facial stripe but they do have large rounded ears. Their coat is coarser and shaggier than the fine down of Red Kangaroos. Females are relatively short and small and rarely exceed 25 kg. Their coat colour varies from light grey through to black. Males are short but very stocky with pronounced forearm musculature when mature. They reach around 50 kg and show a similar variation in coat colour to females but are darker coloured than females and often predominantly black on the upperparts. The underparts are lighter and the tail tip is not black. The Eastern Wallaroo can be distinguished from the Eastern Grey Kangaroo by its less gracile form and blacker coat. Eastern Wallaroos hop on their short legs in an upright posture, which seems less elegant than Eastern Grey Kangaroos on flat ground, but comes to the fore as they effortlessly bound up rocky slopes.
The Eastern Wallaroo is a hill-dweller and so occupies the slopes and ridges, using rocky overhangs and shallow caves as shelter in summer and intense cold in temperate habitat in winter. In some places they inhabit low lying areas of dense scrub. Females tend to be more easily alarmed by people than males who sometimes tolerate quite close approach.The diet of the Eastern Wallaroo has been studied in sympatry with the Eastern Grey Kangaroo in two areas of improved and unimproved pasture in the New England Tablelands of NSW. Both species ate a high proportion of grass ranging from 77-97% in Eastern Wallaroos and 78-98% in Eastern Grey Kangaroos. In unimproved pasture, tussock grasses were favoured in winter when grass quantity and quality is generally low. Thus tussock grasses form a typical diet of Common Wallaroos even though the species of grass may vary across the wide geographic range of the species. In the case of the Eastern Wallaroo (and Eastern Grey Kangaroo) low-fibre grass leaf is the favoured diet and selection is not based on the nitrogen content of the available plants in common with other dietary studies of large kangaroos. Interestingly the Eastern Wallaroo selected a higher quality diet than the Eastern Grey Kangaroo. The average Eastern Grey Kangaroo is larger than the average Eastern Wallaroo and large body size favours higher digestibility of low quality forage which probably explains the difference. However, Euros seem to get by on a poorer quality diet than larger Red Kangaroos when spinifex is the dominant grass. Thus there may be some differences between the sub-species in there dietary physiology or imposed by aridity of the habitat. Eastern Wallaroos were highly selective feeders as expected for a mid-sized herbivore. The bulk feeders amongst the large African mammalian herbivores are missing in Australia with the extinction of the megafauna. The diets of Eastern Wallaroos and Eastern Grey Kangaroos converge in sympatry although they tend to use different habitat. When they are found together in spring, their diets diverge through selection of grasses based on quality.
Males reach sexual maturity from about 18 months of age and active spermatogenesis is present in the testes at 24 months. Females show similar variation in age at sexual maturity and generally first mate towards the end of their second year and give birth about 34 days later. Gestation is on average 33 days and is similar to the Euro but the latter species may have longer oestrous cycles (45 d vs. 34 d) without an intervening birth. Young first exit the pouch around 195 days and vacate at about 260 days. Post-partum oestrus follows permanent pouch vacation within 1-2 days.
Male Common Wallaroos epitomise the extreme dimorphism in the kangaroos as you may see a heavily muscled 50 kg male mating with a diminutive and gracile 15 kg female. This places them amongst the most extreme dimorphism of land mammals. Males compete amongst themselves for consortship with a female who may lead half a dozen or has exclusive dominion with an oestrous female like the sympatric Eastern Grey Kangaroo. Large males are relatively intolerant of smaller males and frequently associate with females, especially where the latter aggregate. Even so individuals are often seen alone and a female may encounter a number of males during her oestrus. Like the arid Euro there is some segregation of large males from other smaller males and females in habitat use, especially during sheltering. However, whereas large male Euros move off the slopes down drainage channels, large Eastern Wallaroo males occupy steeper and more rocky slopes than other size/sex classes.
Eastern Wallaroos are more commonly found alone than sympatric Eastern Grey Kangaroos. Mean group sizes in the New England Tablelands of NSW reflect this with a group size of 4.5 for Eastern Grey Kangaroos and 2.2 for Eastern Wallaroos in a high quality habitat. Group size is in part a function of the species density and were 3.0 and 1.8, respectively in a lower quality habitat (unimproved pasture). Even so Eastern Wallaroos tend to associate with one or more other individuals but large aggregations (10 or more) are rare (1% of observations in the high quality habitat). In contrast about 10% of observations of Eastern Grey Kangaroos in the same habitat were of groups of 10 or more.
Eastern Wallaroos as typical of the species are sedentary and range in relatively small home ranges with some overlap between individuals. Dispersal if it occurs is over relatively short distances at the scale of a typical 3-4000 ha pastoral property in the New England Tablelands.
Dawson, TJ (1995) Kangaroos: biology of the largest marsupials. (UNSW Press: Sydney)
Taylor RJ (1982) Group size in the eastern grey kangaroo, Macropus giganteus, and the wallaroo, Macropus robustus. Australian Wildlife Research 9, 229-237.
Taylor RJ (1983) The diet of the eastern grey kangaroo and wallaroo in areas of improved and native pasture in the New England tablelands. Australian Wildlife Research 10, 203-211.
Taylor RJ (1983) Association of social classes of the wallaroo, Macropus robustus (Marsupialia: Macropodidae). Australian Wildlife Research 10, 39-45.