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.

Leandro Bugoni and Peter Ryan engaged in helpful discussions about identification and ageing of Black-browed Albatross. Michael Brooke and Steve N. G. Howell each dealt with a query. Leandro Bugoni kindly provided comments on the script.

Brooke, M. 2004. Albatrosses and Petrels Across the World. Oxford University Press, Oxford.

Bugoni, L. & Furness, R. 2009. Ageing immature Atlantic Yellow-nosed Thalassarche chlororhynchos and Black-browed T. melanophris albatrosses in wintering grounds using bill colour and moult. Marine Ornithology 37: 249–252.

Burg, T. M. 2000. ‘Genetic analysis of albatrosses: mating systems, population structure and taxonomy’. PhD thesis, University of Cambridge.

Burg, T. M. & Croxall, J. P. 2001. Global relationships amongst Black-browed and Grey-headed Albatrosses: analysis of population structure using mitochondrial DNA and microsatellites. Molecular Ecology 10: 2647–2660. [Crossref]

Flood, R. L. & Fisher, A. in prep. Albatrosses & Fulmarine Petrels. North Atlantic Seabirds series. Pelagic Birds & Birding Multimedia ID Guides, Isles of Scilly.

Howell, S. N. G. 2010. Moult and ageing of Black-browed Albatross. British Birds 103: 353–356.

Howell, S. N. G. 2012. Petrels, Albatrosses & Storm-petrels of North America. Princeton University Press, Princeton and Oxford. [Crossref]

Prince, P. A., Rodwell, S., Jones, M. & Rothery, P. 1993. Moult in Black-browed and Grey-headed Albatrosses. Ibis 13: 121–131. [Crossref]

Prince, P. A. & Rodwell, S. 1994. Ageing immature Black-browed and Grey-headed Albatrosses using moult, bill and plumage characteristics. Emu 94: 246–254. [Crossref]