ABUNDANCE OF MACROPODS IN NORTH-EASTERN NEW-SOUTH-WALES, AND THE LOGISTICS OF BROAD-SCALE GROUND SURVEYS

A broad-scale ground survey of macropod abundance in north-eastern New South Wales was undertaken in 1989-90. The survey area was stratified into an eastern and western region, and within regions by habitat on the basis of vegetation and topographic criteria. Macropod density in each stratum was estimated from walked line transect counts for five s pecies: Macropus giganteus, Macropus robustus, Macropus parryi, Macrop us rufogriseus and Wallabia bicolor. Within sampled strata, macropod d ensity was substantially higher in the western region than in the east ern region. Macropus parryi occurred in only trace numbers in the east ern region, with the number of sightings too small for reliable densit y estimation. No M. parryi were sighted in the western region. Macropu s giganteus and M. rufogriseus were the dominant species in sampled st rata in the eastern region, while M. giganteus and M. robustus were do minant in the west. Overall, pre-survey activities of habitat digitisi ng and liaison with landholders required approximately the same effort as actual survey work. Liaison with landholders required relatively m ore time in the eastern region, where human population was higher, tha n in the western region. Incomplete coverage of planned transect route s, due mainly to impenetrable vegetation, lead to a positive bias of n o more than 10-20% in population estimation for M. giganteus and M. ro bustus, and an unknown bias for the other species. The use of broad ve getation information on 1:100 000 map sheets for habitat stratificatio n limited the scale at which analysis of sightability could be underta ken. Macropus giganteus and M. robustus are commercially harvested in the western region. Annual commercial harvest rates in the three years prior to the survey were conservatively estimated to be less than 0.9 % for M. robustus and less than 54% for M. giganteus.