Provisioning rate and attendance patterns of Wandering Albatrosses at BirdIsland, South Georgia

We investigated foraging behavior of Wandering Albatrosses (Diomedea exulan s) breeding at South Georgia to assess how sex and season-specific foraging patterns relate to provisioning performance. We estimated Wandering Albatr oss chicks require 60-65 kg of food over the chick-rearing period; males de liver 54% of this total. Meal size delivered by both sexes remained essenti ally constant throughout the post-brooding chick-rearing period, but foragi ng trip duration varied considerably. Females made consistently longer fora ging trips and delivered smaller meals but transported an average load that was 20% heavier in proportion to their body mass than males. We suggest th at chick-rearing places greater demands on females compared with males and Wandering Albatrosses work hard to deliver food during the first half of ch ick rearing (at the expense of their own condition), thereafter reduce thei r work rate, presumably so as not to compromise their survival.