Hello,

I'd appreciate some help with gull ID. Last May I visited March Point,
and took these photos of a pair of large, adult gulls. I am still not
confident about judging the finer details of head and bill shape, so I'm
stuck with the ID.

The one on the left (with black primaries) looks close to a Western, and
the one on the right (with grey primaries) looks, I think, close to a
Glaucous-winged. However, the colour of the mantle on both appears to be
the same, so at least one must be an 'Olympic' hybrid. Looking at them
now, I'd say the left bird is Western and the right is Olympic, but I
understand that Westerns are fairly scarce at March Point.

http://macaulaylibrary.org/asset/45585551?__hstc=60209138.ae38b1bcc04d74e5c653a0472da7b0c5.1419882896469.1484520077156.1484529880961.647&__hssc=60209138.65.1484529880961&__hsfp=3090701989

http://macaulaylibrary.org/asset/45585561?__hstc=60209138.ae38b1bcc04d74e5c653a0472da7b0c5.1419882896469.1484520077156.1484529880961.647&__hssc=60209138.65.1484529880961&__hsfp=3090701989

I'd appreciate suggestions and pointers for ID-ing these two birds.

Thanks!

Ben