Mew Gull Larus canus canus; heinei; kamtschatschensis; brachyrhynchus

(last update: March 12, 2012)

Mew Gull BLB E139328 8cy, 10 May 1997, Malmö, Sweden.

Figure 30: E139328 (0/0) seven-year old canus (8CY), the single individual among 73 birds of 3-12 year old in which the black sub-terminal band is completely missing (P10 mirror completely merged with white tip). In the reference group this occured in 6% of the birds. 10 May 1997. Originally ringed on 09 February 1991 in Belgium.

Our seven seven-year old birds show 2 or 3 mirrors, black on 5 to 7 primaries and white tip on P7-P9. Fig 29 shows a seven-year old bird which is the same individual as the four-year old bird in fig 23. There are slight differences between these plumages, especially the wing-tip pattern changed gradually throughout the years: the mirror on P10 is now merging the white tip (broken band on P10), and suddenly it has developed a black spot on P5 (these characters were not present as four-year old bird).
Fig 30 (below) shows a canus (breeding bird in Malmö, killed in traffic) on which the black sub-terminal band is strongly reduced; this is the only bird showing this amount of white on P10 in our set of 73 photo-documented 3-12 year-old birds. In the reference-group of 100 anonymous adult birds (no certainty about exact age) we found this character on six 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.