Australia's tree-kangaroos: current issues in their conservation

Abstract

Lumholtz's tree-kangaroo ( Dendrolagus lumholtzi) and Bennett's tree-kangaroo ( Dendrolagus bennettianus) are the two largest arboreal folivores in Australia and are both restricted to the tropical rainforests and adjacent forest communities in North Queensland. Both species display cryptic and secretive behaviour, and consequently are poorly studied. Bennett's tree-kangaroos are found within a relatively small area (∼2000 km 2) of the Wet Tropics, however the majority of this area is within a protected `World Heritage Area', and consequently the conservation status of this species is considered moderately safe despite its rarity. The overall distribution of Lumholtz's tree-kangaroo, which is also considered rare, covers a larger area (∼5500 km 2), which also has considerable overlap with the `World Heritage Area' (WHA). Despite this, the species appears to maintain its highest densities in forest outside the WHA conservation zone. Lumholtz's tree-kangaroos are more commonly found in the fragmented forests on the Atherton Tablelands, and are often associated with remnant and secondary rainforests on basalt soils. These forest communities are considered rare and are poorly represented in existing reserves. This paper considers the conservation issues for both of these species, but focuses particularly on Lumholtz's tree-kangaroos for which more data is available. Issues discussed include the loss of habitat outside the World Heritage Area, road deaths of animals, predation by canids, traditional hunting, and fecundity and recruitment. Measures for the conservation of these species are suggested, including measures for the retention of habitat on private land, public education, translocation and captive breeding. The applicability of research on Australian tree-kangaroos to the conservation of the eight species of tree-kangaroos in Papua New Guinea is also considered.