Black-browed Albatross Thalassarche melanophris primary moult timing in the fourth prebasic moult

Abstract

The aging of immature Black-browed Albatrosses Thalassarche melanophris is reasonably well understood using a combination of primary moult sequence and timing (see Appendix), and progression in plumage aspect (bill colour and pattern, head and neck markings, and whitening of the underwing-coverts). The initial work of Prince et al. (1993) and Prince & Rodwell (1994) studied ringed (known-age) non- breeding Black-browed Albatrosses visiting a study colony on Bird Island, South Georgia between December 1989 and February 1990. Adding to this, Bugoni & Furness (2009) examined and photographed a sample of 33 birds captured at sea off the Brazilian coast in February to June 2006 and July to September 2007. Howell (2010, 2012) provided a number of at-sea photographs illustrating many of the immature age groups. These studies are important to understanding the impact of bycatch on different age groups, and to aging and identification for field birders.