Mew Gull Larus canus canus; heinei; kamtschatschensis; brachyrhynchus

(last update: March 12, 2012)

Mew Gull RUM MB-350502 4cy, 01 January 1998, Malmö, Sweden.

Figure 22: MB350502 (374/90,4) three-year old bird (4CY), probable female. Phenotypics of canus, but measurements of heinei. 01 January 1998. Ringed on 19 June 1995 in Arkhangelsk, Russia (64.28N, 40.50E).

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), especially if birds also have a white tip on P8 (to separate it from advanced second-year birds). An interesting example bird from the overlap zone between canus and heinei is shown in fig 22 (below). This probable female was ringed as pullus near Arkhangelsk on 40E and shows the typical grey tone for canus. The photo is taken with flash, but we remember the bird in the field to be comparable with the tones in this image.

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.