Habitat and Geographical Range
The koala is an arboreal herbivore native to Australia. While it is colloquially often referred to as a “koala-bear,” the koala is in fact a marsupial, its closest living relative being wombats.
The koala tends to inhabit the coastal areas of the southern and eastern regions of the mainland, preferably in eucalypt woodlands, and spanning about 1,000,000 square kilometres. There is some diversity in their habitats, as they may be found in open forests and woodlands, as well as both tropical and temperate climates. When living in semi-arid climates, studies indicate they have been shown to prefer riparian areas, which are the interface between land and river.
The koala population can only truly thrive if there is a suitable habitat, of which the most important facts are the presence trees available, and the presence of conspecifics. The advocacy website, Save the Koalas, insists that 80% of Koala habitat has been destroyed since the Europeans first settled Australia.
The koala home range is comprised of a number of different “home trees” which they visit regularly. Often koala’s overlap the home ranges of other koalas, however the male rubs his scent gland on his home trees to mark it as his territory. The removal of home trees is incredibly detrimental to the Koala, who depends on the trees for food and/or shelter, and thus a koala without a home tree is at a severe risk of mortality. According to Ellis et al. (2002), Koalas in central Queensland during the observation period were found to use on average 93 trees as a male and 56 trees as a female, while occupying 135 and 101 hectares of home range respectively. Koala’s were observed returning to previous daytime trees to roost infrequently, and were known to use non-fodder tree species for daytime roosting.
The Australian Department of Environment and Climate Change released an information brochure on the conservation and identification of Koalas in 2007. The brochure stresses that despite being one of the most iconic Australian animals, koalas are considered a “vulnerable” species under the Threatened Species Conservation Act 1995 (TSC Act). There has been a steep decline in Koala abundance, and have disappeared from up to 75% of their original ranges. Since the koala has a relatively low recovery potential due to a small breeding rate, it is a species of great importance to wildlife conservationists. The department suggests identifying Koala habitat based on:
1. Jackson, S. (2003). Australian Mammals: Biology and Captive Management. CSIRO Publishing. pp. 147–51. ISBN 978-0-643-06635-9.
2. Smith, A. G.; McAlpine, C. A.; Rhodes, J. R.; Lunney, D.; Seabrook, L.; Baxter, G. (2013). "Out on a limb: Habitat use of a specialist folivore, the koala, at the edge of its range in a modified semi-arid landscape". Landscape Ecology 28 (3): 418–26. doi:10.1007/s10980-013-9846-4.
4. Ellis, W. A. H., Melzer, A., Carrick, F. N. and Hasegawa, M. (2002) . Tree use, diet and home range of the koala (Phascolarctos cinereus) at Blair Athol, central Queensland . Wildlife Research 29 , 303–311.