Mew Gull Larus canus canus; heinei; kamtschatschensis; brachyrhynchus

(last update: March 12, 2012)

Mew Gull canus DKC 5100346 3cy, 11 January 1997, Malmö, Sweden.

Figure 21: 5100346 (375/94,6) three-year old male (3CY), probable canus, with black markings on primary coverts and alula. 11 January 1997. Ringed in Denmark, 12 February 1996.

Most three-year old birds have two mirrors. But we found one bird (out of 24 proven three-year birds) already showing a small mirror on P8 (see fig 20). This bird could not be aged correctly as three-year old without ring-information. When adult-like Mew Gulls have a dark alula, this may indicate third-year age. In the group of 18 proven third-year birds, we found four showing this dark alula. However, three out of 15 four-year old birds were still showing a dark alula and even one out of twelve five-year old birds showed this feature. The combination of a dark alula together with small dark markings on wing-coverts is supposed to indicate third-year birds (see fig 21 below), especially if birds also have a white tip on P8 (to separate it from advanced second-year birds).

Figure from:
Is it possible to age subadult Mew Gulls Larus canus?
by: Kenneth Bengtsson & Lennarth Blomquist, publication in: Anser 2-42(2003): p 73-92.