CLOSED: Glaucous-winged Gull and Western Gull?

Hi, here are two gulls I saw in Seattle last week. I guess the first one is a Glaucous-winged Gull and the second one is a Western Gull?

I have heard that Glaucous-winged Gulls and Western Gulls can interbreed. How will their offsprings look like?

Thanks,
Cui

The photos are in the wrong order. The first one is Western Gull, the second one is Glaucous-winged Gull. Is that correct?

Cui

Yep, first is Western. But the second looks like an "Olympic Gull" - one of those hybrids (yes, they exist, and are common in the Seattle area). The primary tips are a little too dark for pure G-wG. The bill pattern shows it isn't a full adult, probably 3rd or 4th winter.

Resin

Gulls are tricky...

Will gray back + dark primary tip = Herring Gull?

Thanks,
Cui