Mew Gull Larus canus canus; heinei; kamtschatschensis; brachyrhynchus

(last update: March 12, 2012)

Mew Gull (Larus canus) 2nd cycle (2CY): September - October

Mew Gull is a widespread species on the northern hemisphere with several sub-species: in N America brachyrhynchus, in W Europe nominate canus, in W Asia and Russia heinei and in the Far East sub-species kamtschatschensis.
The American race brachyrhynchus is a breeding bird of Alaska, the American West coast and inland Canada. After the breeding season, it disperses south along the coast to California. Brachyrhynchus can be readily told from nominate canus, and therefore sometimes considered a full species: Mew Gull. The differences can be found in the bill (in some birds obviously small), but most in plumage.
Nominate canus is a common breeding bird in North Europe, wintering both in the breeding area and slightly south, to the northern coast of the Mediterranean. 
The race heinei breeds from White Russia eastwards to central Mongolia, in a broad band over the tundra region of inland U.S.S.R. It can be found wintering in the central Asian states, southern Black Sea and Caspian Sea and further south to the Persian Gulf. Part of the eastern population of heinei may follow a more eastern route to the coast of China.
Race kamtschatschensis breeds in eastern Siberia and, as the name indicates, Kamtschatcha. In winter it moves southwards along the coast, wintering in Japan, the Korea's and China. It is the largest race, almost as large as Herring Gull.  The description below largely follows from P.J. Grant: "Gulls, a guide to identification".

Mew Gull canus 2CY, October 19-23 2016, Grou, the Netherlands (Mars Muusse). 2CY canus often has a bluish tone on the bill. Left bird is extreme in showing only limited spotting on head and neck.

2CY Mew Gull

Mew Gull has 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.

From June to October, a complete moult will bring birds in so-called "second winter" plumage. The head and hind-neck are strongly spotted and from the hind-neck, these spots form streaks, creating a collar running down the sides of the breast. Under-parts, tail-coverts and rump are white. The second generation primaries resemble adult primaries, but the black is more extensive in the outer-wing, with black sub-terminal markings down to P4 or even to P3. The greater and median primary coverts and the lesser coverts in the carpal edge are dark centred as well. The white tips on the outer primaries are ill-defined, wearing off quickly and the mirrors on P9 and P10 are smaller than in full adult plumage. The tail is all-white in race canus. The iris is brown, the greyish bill has a clear black bill-band. 
After the complete moult in June to October, brachyrhynchus may still show several immature feathers in the wing. The central tertials and some of the tail-feathers may show dark immature centres (even creating some kind of a tail-band in some individuals). Immature features can also be found in the central greater coverts and in the carpal edge and can even be found on the upper-tail and under-tail coverts. These immature features are less often found in nominate canus, which show no vestiges of a tail-band from autumn 2cy onwards ("second winter" plumage and later). In this respect, brachyrhychus resembles Ring-billed Gull, L. delawarensis. From autumn 2cy onwards, the iris in brachyrhynchus may turn obvious pale.
The race kamtschatschensis shows similar amount of patterning after the complete moult as brachyrhynchus, with many immature markings in tail, tertials and wing-coverts. Moreover, (all?) kamtschatschensis still shows black tips on the white under-wing coverts.

Although literature mentions for 2CY October: "These immature features are less often found in nominate canus, which show no vestiges of a tail-band from autumn 2cy onwards ("second winter" plumage and later)", you may find 2CY birds in western Europe - matching the description for nominate canus - that do show black in the tail.	Classic 2nd generation primaries. Also in resting birds, when patterns on the primasry coverts are hidden underneath the wing-coverts, the exposed primary tips may still reveal a bird's age. 2nd generation primaries often are still brownish and lack the clear-cut white tips.
You may find 2CY birds in western Europe - matching the description for nominate canus - that do show dark centres on the tertials. Here, two example birds.
In many 2CY autumn birds, the black markings on the upperwing are obvious when the wing is spread. 2nd generation P9-P10 may show large mirrors.	In many 2CY birds, the black markings on the upperwing are mirrored and apparent on the underwing as well in the coverts.

"brachyrhynchus" Mew Gull 2CY Sept - October

"canus" Mew Gull 2CY September - October

"heinei" Mew Gull 2CY September - October

"kamtschatschensis" Mew Gull 2CY Sept - October