Adult Steppe Gull (Larus (c.?) barabensis).
The mirror on P10 is separated from the white tip by a large black
band. Note the eye color; on average barabensis looked
paler-eyed that cach./ponticus, but there was plenty of
variation and overlap. Also note the thin black subterminal band
on the bill that does not extend across the whole depth of the
lower mandible:
