HABITAT PREFERENCE AND FACTORS CONTRIBUTING TO THE INCREASE IN NUMBERS OF BUSH STONE-CURLEWS (BURHINUS GRALLARIUS) ON COOCHIEMUDLO ISLAND, SOUTH-EAST QUEENSLAND

摘要

Bush Stone-curlews (Burbinus grallarius) occur in high densities on Coochiemudlo Island in southern Moreton Bay and other offshore islands. This contrasts with the situation on the adjacent mainland and in southern Australia. In order to start to understand why Bush Stone-curlews are more abundant on islands, we examined the trend in community counts of this species on Coochiemudlo Island made over 15 years. We also compared habitat preferences based on 18 paired presence/absence sites on the island. Count data show the numbers of Bush Stone-curlews detected increased in the early 2000s and have remained stable since 2007. Habitat data indicate Bush Stone-curlews favour locations with low to moderate shrub cover, low grasses and greater amounts of leaf litter. As well, curlews were most often found within 20 m of septic tanks and 100 m of water sources. Retention of cleared, undeveloped land corridors with a grassy understorey could encourage the maintenance of Bush Stone-curlew population numbers on Coochiemudlo Island. Septic tank trenches may be providing attractive feeding areas, contributing to the high density of Bush Stone-curlews on the island. If this is true, the population may decrease from the current estimate of 77 adult pairs and 37 juveniles when septic tanks become inactive following the installation of sewerage.