Large Macropods Research Articles

Distribution and abundance of kangaroos (Marsupialia: Macropodidae) at the time of European contact: Victoria.

The dominant species of large macropods in Victoria are the Eastern Grey Kangaroo (Macropus giganteus) and the Southern (= Western) Grey Kangaroo (M. fuliginosus). On the limited historic data available there is no indication that their ranges have changed since European settlement. The Red Kangaroo (M. rufus) was restricted to the northwest corner of the state, then as now. Moderate densities of Grey Kangaroos at settlement increased under forest clearing, probably peaking about the mid-nineteenth century. With intensification of farming and associated heavy hunting they declined again to establish by about the turn of the century the distribution of modera te density that we see today.

Distribution and abundance of spectacled hare-wallabies and euros on Barrow Island, Western Australia

Spectacled hare-wallabies (Lagorchestes conspicillatus) and euros (Macropus robustus isabellinus) occur on Barrow I. at densities of 42 and 8 km-2, respectively, which result in estimates of total population sizes of c. 10000 and 1800, respectively. Spectacled hare-wallabies occur throughout the island in all habitat types; euros tend to be concentrated in the deeply dissected country in the central-west of the island. Limited areas of floodout flats are important feeding areas for euros, being the only major habitat on the island dominated by grasses other than Triodia. There was no significant difference between density of either species on the two halves of the island (one half is dominated by a commercial oilfield; the other is relatively undisturbed). Barrow I. is the smallest island off the Australian coast to have successfully supported a population of large macropods for the 8000-10000 years since separation from the mainland by rising sea-level. Hence, the population estimate of euros on Barrow I. provides an empirical measure of the viable population size necessary for the long-term survival of large macropods. This estimate is nearly two orders of magnitude less than that estimated from a theoretical model of minimum viable population size (Belovsky 1987).

Competitive interactions in the dietary preference of kangaroos and sheep, cattle and goats in inland Australia

The trophic ecology of the large macropods (kangaroos and euros) is summarized. Introduction of livestock has generally favoured the build up of numbers of kangaroos in the arid zone. The reasons are discussed. This paper also reviews work in the arid and semi-arid regions of Australia on diet selectivity of sheep, cattle and goats. Comparisons between the diets selected by domestic livestock and the large marsupials (red kangaroo, Megaleia rufa and euro Macropus robustus) are considered in detail. The degree of competitive interaction and the implications are discussed. Considerable overlap occurs in the diet of goats and cattle, and between sheep and cattle. Sheep, cattle and kangaroos eat similar foods, where there is a wide choice, but the degree of competition tends to be minimized by spatial and temporal separation. Under conditions of severe feed shortage kangaroos and livestock both concentrate on areas supporting the most nutritious forage and competition is intensified.