Influence of adult breeding experience on growth and provisioning of Wandering Albatross Diomedea exulans chicks at South Georgia

For most seabirds, reproductive performance improves with age; in albatross es this is thought not to be so (experience being acquired before starting breeding) but only one study (of chick growth in a single season at one sit e) has specifically addressed this. We compared the provisioning performanc e and growth rates of chicks of Wandering Albatrosses Diomedea exulans bree ding for the first (IN), second and third (LE) and fourth or more times (EE ) on Bird Island, South Georgia in the austral winters of 1996 and 1997. Eg gs from EE adults were significantly heavier than the other two categories and these chicks had a greater mass and longer wings up to 160 days of age and longer culmen and tarsus up to 115 days old. However chicks from all ca tegories fledged at the same average mass, size and age. No significant dif ferences between categories in feeding frequency or meal size were detected but experienced adults made shorter long foraging trips and spent more tim e at the nest than less experienced birds. Adults that remained at the nest gave chicks smaller meals than those that left immediately after feeding t he chick. Although provision of smaller but more frequent meals by experien ced adults promotes more rapid chick growth, the resulting differences do n ot persist into the late chick-rearing period. Our results were very simila r to those from Iles Crozet in the Indian Ocean, supporting the hypothesis that when Wandering Albatrosses start to breed they are fully competent for agers but that it takes a while, during early chick-rearing, for birds bree ding for the first time to adapt to the additional demands of provisioning a chick.