The Grey Kangaroo Overlap Zone

Abstract

The distributions of the two species of grey kangaroo, Macropus giganteus of eastern Australia and M.fuliginosus of southern Australia. overlap in a zone of 0.68 X 10*6 km2 in south-eastern Australia, the zone including parts of South Australia. Victoria, New South Wales and Queensland. The species' boundaries determining the overlap zone are mapped and the geographic trends in density within it are determined for each of the two species. Whereas the western boundary of M. giganteus has moved inland this century, possibly as a response to an increased number ofwatering points, there is no strong indication that M. fuliginosus has extended its range significantly. The recent discovery of the latter species in Queensland over an area of 100 000 km2, reported here for the first time, need reflect nothing more than the difficulty of differentiating the two species in the field.