Aging Immature Black-browed and Grey-headed Albatrosses Using Moult, Bill and Plumage Characteristics

Abstract

We describe how to age immature Black-browed Diomedea melanophris and Grey-headed Albatrosses D. chrysostoma up to age 6 years (when they have usually acquired adult characteristics), from a combination of the age and pattern of moult of flight feathers, bill colouration and certain plumage characteristics. This is based on known-age birds retrapped at colonies during the breeding season. Ageing of immatures at other times may be complicated by them being in active moult; we provide further guidance for these circumstances.