Responses of lumholtz's tree-kangaroo (Dendrolagus lumholtzi) to loss of habitat within a tropical rainforest fragment

摘要

During an ongoing study of habitat use by Lumholtz's tree-kangaroos (Dendrolagus lumholtzi), an unexpected opportunity arose to study the responses of this rare arboreal marsupial to habitat disruption. A study was underway on the Atherton Tablelandin northern Queensland, Australia, when half of a 20 ha rainforest fragment was unexpectedly clear felled by the landowner. Prior to clearing, 6 animals had been fitted with radio collars to monitor their locations and activity within the fragment. Mostanimals responded to clearing by remaining in trees until just before they were felled. Animals then fled for short distances, but returned to their home ranges within 12 to 24 hours. Nine additional resident animals were captured after forest clearingand radio collared, and along with the original animals were tracked at 12 hour intervals for several months. Six females and 5 males directly affected by clearing continued to use their original home ranges, amongst the 1-2 m tall tangles of woody debris. Contrary to expectations, animals did not relocate to nearby forest blocks, and only one animal established a completely new home range. Mortality rates of affected animals increased after clear felling, with at least 4 perishing from attacks by domestic dogs or dingoes. Although some surviving tree-kangaroos lived within the debris for several months, their prospects for long-term survival were poor as the debris was eventually burnt to create cattle pasture, destroying the already modified habitatand leaving them vulnerable to predators. The remarkably strong site-tenacity of this species indicated that habitat availability was critically limiting to their populations, and that displaced animals have limited prospects for survival.