These four adult Herring
Gulls (Larus argentatus argenteus/argentatus) were
photographed at Peterhead (north of Aberdeen), northeast Scotland on Feb 26-28, 2009. They each have a small gray "mirror" on P9 or P10. These were found among c. 30 photographed adult birds where the open primary pattern is visible from below - NOTE: the only photographer bias was slightly towards birds with less black/more white.
1): small gray "mirror" intrusion from inner edge of P10 at c. midpoint.
Also note the following smith-like features:
much retained winter markings in late February;
mirror on P10 only, with obvious black subterminal band;
black to P5;
pattern of black on P5 is a shallow "W";
black on upper side of P8 appears to reach to the coverts, or almost-so.
Missing smith-like features:
P10 tongue not long and truncate (instead short - but truncate):
winter markings not smudgy (instead rather streaky - but rear-neck not assessable);
bill base not washed-out creamy or pinkish (instead fairly bright yellow).
Features not assessable from these photos:
shape of black on outer web of P8 and P7;
length and pattern of P8 tongue;
shade of gray on upperparts.
2): on right wing a small gray "mirror" on inner web of P09 at c. 2/3rds distally:
3): on left wing a small isolated gray "mirror" on inner web of P10 near the base of the inner web black area:
4) - this one from Dix Pit, Oxon, U.K. on January 17, 2008. From c. 10 adult birds photographed in such a way as to show the underwing sufficiently. A large gray "mirror" touching the inner edge, and almost connected to the gray tongue:
