An experimental study of the translocation of noisy miners Manorina melanocephala and difficulties associated with dispersal

Abstract

The aims of this study were to determine whether translocated noisy miners Manorina melanocephala were assimilated readily into noisy miner populations resident at release sites and, secondly, whether the number of birds in a release group influenced the subsequent behaviour, movement patterns and fate of translocated individuals. Birds were released in duos ( n = 5) or in groups of six ( n = 5). One bird in each duo or group was fitted with a radio transmitter. Although most translocated birds survived at least a month following translocation, they were not assimilated readily into resident populations of miners, but instead wandered much further (mean maximum distance from release site = 4·2 km) than the average diameter of the species' home range (∼ 200 m). At least two of the 40 translocated birds returned to their capture site; a distance of 18 km. The distances travelled by radio-tagged birds from their release sites rendered invalid the assumption that one release group/duo did not influence how another group/duo behaved. The difficulties such widespread dispersal pose to attempts at experimental examination of factors influencing the success of translocations are discussed.