Breeding and movements of wing-tagged silver gulls (Larus novaehollandiae) at the largest colony in New South Wales

Abstract

Wing tags were used in preference to colour/metal band combinations to increase sighting frequency of silver gulls. Wing tags did not affect return rate of breeding adults to the colony compared with banded gulls. Approximately one-third of gulls lost their nests following wing-tagging. There were no instances of double-brooding with fledging success from both attempts. A total of 42% of adults that returned and bred, nested more than once in a season. Up to 4 clutches were produced by pairs within a season. Successful raising of young typically occurred from the first brood of the season. Successful breeders usually nested only once in any one season. In all, 19% of pairs successfully fledged young, but the percentage of young fledged from the number of eggs laid was much lower (5.3%). Nest sites were rarely repeatedly used by the same nesting pair. Individuals moved considerable distances between successive nesting sites within and between seasons. Fidelity to colony was 68% and to mate 22%; these estimates are lower than those from other colonies.