These four 1st-alternate/2nd-basic Slaty-backed
Gulls (Larus schistisagus) were photographed at
Gambell, Alaska by Tony Leukering on 4th September, 1999. It is
interesting to note that on all three non-flying birds there is
the indication that the row of scaps sitting just above the lesser
wing -coverts are the darkest part of the "new" upperparts
feathering:
This bird has a much more advanced molt of the wing-coverts, and
its primary molt is about one full primary ahead of the above
birds; also note that the tail appears to have a paler basal band:
note the odd molt of this bird: P8-P10 are old, P7 is almost grown,
but P1 is only half-grown; compare this to a
flying adult from Nome :
