Reduction of bias when estimating bird abundance within small habitat fragments
We used the distance detection function from five-minute point counts entirely within large woody vegetation patches to derive a method of truncating counts of birds detected close to the observer to estimate their relative abundance in small habitat patches. Our method trades off loss of information by truncation of bird sightings at successively larger distances from the observer to reduce sampling bias. Truncation of counts to include detections within 10 m of the observer gave similar absolute density as distance methods for the six most abundant native and six introduced species.