Typical juvenile nominate fuscus are hard to describe as the variation in colour and shape is extensive, but on average a few points may indicate specific identification. Note however that single individuals from graellsii, intermedius and fuscus are almost impossible to tell apart as there exists a large overlap. For comparison, a juvenile intermedius from Götenborg, SW Sweden is added at the bottom. Images of ringed graellsii and unidentified graellsii / intermedius can be found in the Lesser Black-backed Gull sections of August, September, October and November-December.As can be seen in the pictures, most birds show a complete juvenile plumage by early August. Numbers are too low to draw any conclusions about the post-juvenile moult, but at least a few birds started the post-juvenile moult as early as August 07 at the Tampere landfill, in SW Finland (see e.g. this bird and CHR5). Jonsson (in his article in Birding World) mentions that post-juvenile moult may start in August in some individuals. On the other hand, juvenile fuscus are found in completely juvenile plumage in February.

The Lesser Black-backed Gull, Larus fuscus, in Greenland

BY: D. BOERTMANN

IN: ARCTIC, VOL. 61, NO. 2 (JUNE 2008) P. 129– 133

ABSTRACT. The lesser black-backed gull (Larus fuscus) became a frequent visitor in Greenland in the mid-1980s. Breeding was confirmed in 1990, and today the species is a common breeder in at least two areas in Southwest Greenland between 60° and 66° N. The current breeding population is estimated at more than 700 pairs. Even though the colonization of Greenland by this species may be primarily the result of an increasing source population in Northwest Europe, climate change most likely will facilitate its expansion farther north in Greenland and probably also farther west to eastern Canadian coasts.