CLOSED: Herring Gulls with a Ring-billed Gull?

Hi, I took that photo in Washington DC last weekend. I used to think all of them are Ring-billed Gulls, but I find the ones on the right have pink feet. Are they Herring Gulls?

Thanks,
Cui

I wonder if the ones with pink feet are immature Ring-billed Gulls. I don't think the Herring Gulls have a ring-bill.

http://www.allaboutbirds.org/guide/Ring-billed_Gull/id


http://www.allaboutbirds.org/guide/Herring_Gull/id


By-the-way, I think you made the guy on the left self-conscious. He's looking at his feet (maybe trying to figure out the color?) :o)

Yep, young Ring-billed Gulls - also note the brown near the tips of the wings.

Herrings would be obviously larger in a comparitive photo like this.

Resin

Interesting!

Thanks,
Cui