The low tide distribution of Eastern Curlew on feeding grounds in Moreton Bay, Queensland

Abstract

We assessed the broadscale distribution of Eastern Curlew among tidal flats within Moreton Bay in order to identify important intertidal feeding habitat. Low tide surveys were conducted with the help of 60 volunteers who counted at 160 sites during summer 1998-99 and winter 1999. A site typically comprised a section of tidal flat from high water to low water, or a sandbank or banks. Sites varied in size (0.68 - 474 ha), substrate, topography, and other features, and covered approximately 41.3% (9,500 ha) of the intertidal habitat within Moreton Bay. There was a high and significant correlation (P<0.0005), between the site counts on different days within a month and different months within a season, across all sites. Winter count numbers totalled about 25% of summer counts, and the pattern of variation in numbers across sites was generally similar to that seen in summer. The within-season constancy of Eastern Curlew numbers across sites suggests that short surveys can give reliable results. Eastern Curlew densities (numbers.ha-1.site-1) also showed a strong correlation between summer and winter counts, and sites supporting high abundances of Eastern Curlew also frequently supported high densities. Key areas in terms of Eastern Curlew abundance and density were Lota, North Stradbroke Island, Moreton Island, Fisherman Islands, Hays Inlet, Deception Bay, and Pumicestone Passage.