Relationships between food supply and growth in albatrosses: an interspecies chick fostering experiment
The Black-browed Albatross Diomedea melanophris and Grey-headed Albatross D. chrysostoma are similar in size and weight and breed at the same time, but have substantial dietary differences. To study the effects of diet on growth, the eggs of ten Grey-headed were exchanged with those of ten Black-browed Albatrosses and the growth of these fostered chicks were compared with those reared by their own parents in the same season. Although the chicks of both species altered their growth patterns in response to dietary differences, they were limited by species specific constraints on growth. These results, together with observations on breeding success, suggest that both the growth patterns of the chicks and breeding patterns of the adults of these two species are adaptations to differences in their food and feeding ecology.