The distribution of Bush Stone-curlews (Burhinus grallarius) in South Australia, with particular reference to Kangaroo Island

Abstract

Bush Stone-curlews (Burhinus grallarius) have suffered major declines and a contraction of their range across southern Australia. A total of 414 records of Bush Stone-curlews was obtained for South Australia, from the late 1880s through to 1995. Early records were widespread across the state. By 1940, however, the decline of Stone-curlews was evident, and by 1980 there were few records on the mainland, with most remaining records coming from Kangaroo Island. Call-playback surveys were undertaken across Kangaroo Island between September 1995 and July 1996 to determine the distribution of Stone-curlews on the island. The birds were recorded at 110 of the 147 (75%) survey sites. Combined with records obtained from landholders, Bush Stone-curlews were found to be distributed throughout the agricultural landscape on the island, being detected at 96% of survey sites in agricultural areas. In contrast, the birds were present at only 8% of survey sites in large remnants of native vegetation. Based on their wide distribution, the Kangaroo Island population of Bush Stone-curlews is now the stronghold for the species in southern Australia. In the absence of foxes, Bush Stone-curlews have benefited from vegetation clearance on Kangaroo Island, with the species being widespread in agricultural areas with remnants of native vegetation and largely absent from extensive areas of dense native vegetation. Call playback provides an efficient censusing technique to monitor population trends of Bush Stone-curlews on Kangaroo Island.