Mew Gull Larus canus canus; heinei; kamtschatschensis; brachyrhynchus

(last update: March 12, 2012)

Mew Gull canus 2cy, January 05 2002, Etaples / Boulogne-sur-Mer, France (50.42N,1.34E).

A typical 2cy ("first winter" plumage) from mid winter. Most of the bird's upper-parts are still juvenile, but the scapulars, mantle, head and under-parts are moulted, replaced by second generation feathers. 

In Mew Gull, the partial autumn moult (moult into so-called "first winter"  plumage) includes the body and head feathers. This moult starts as soon as the nest is abandoned and continues to late September in nominate canus. The race heinei, which breeds on northern latitudes may appear all juvenile well into December. The head and breast are moulted to second generation feathers, most reminiscent of the juvenile feathers. The mantle and scapulars are moulted to plain grey second generation feathers in canus.
Brachyrhynchus in 1cy looks paler on average and more washed-out than nominate canus. In canus, the second generation scapulars and mantle feathers are plain grey; in brachyrhynchus, these feathers are often mottled pale brownish, lacking most of a grey tone. The differences between the two taxa become more striking in the first months of 2cy, when the complete wing looks faded in brachyrhynchus, washed brown, including the primaries. The tail will be brownish as well, lacking a clear-cut tail-band as in canus. Brachyrhynchus has the base of the tail-feathers mottled. In general, the upper-tail coverts, head, under-parts and rump are more uniform brown-grey. 

The next moult is a partial moult in spring. It starts in February and is completed by April, leaving birds in so-called "first summer" plumage. The head turns much whiter, with the white chin, throat and breast white and dark streaking confined on the crown, hind-neck. The tertials, wing-coverts, primaries and tail-feathers are excluded from this moult and turn paler, the grey parts turn almost white and very worn at the tips. The dark primaries and the lesser coverts start to bleach to pale brown. The second generation grey scapulars create a saddle. The legs are greyish.