A combined French and South African study published online in the journal Marine Biology this month shows clear differences in diet quality between breeding Grey-headed Albatross Thalassarche chrysostoma and their chicks at South Africa's sub-Antarctic Marion Island in the southern Indian Ocean in April 2006.
Diets of adults and chicks were assessed using stable isotope ratios and fatty acid profiles of blood and/or stomach oils, in addition to stomach content analysis. Fish of the family Macrouridae and cephalopods (particularly the onychoteuthid squid Kondakovia longimana) were the primary prey, whereas crustaceans (Antarctic Krill Euphausia superba) represented a smaller proportion of the stomach contents.
Chicks were found to be fed at a higher trophic level, receiving nutritious fish with adults keeping much of the less nutritious zooplankton for themselves.
Reference:
Richoux, N.B., Jaquemet, S., Bonnevie, B.T., Cherel, Y. & McQuaid, C.D. 2010. Trophic ecology of Grey-headed Albatrosses from Marion Island, Southern Ocean: insights from stomach contents and diet tracers. Marine Biology DOI 10.1007/s00227-010-1488-y.
John Cooper, ACAP Information Officer, 30 April 2010