The Ring-billed Gull is an abundant Gull throughout North America and some of the Caribbean. They are known to occaisionally interbreed with similar species and study of this gull and related species is a topic of serious study.
These gulls can be found on the coasts, but are much more common inland. They tend to congregate around rivers and lakes and can often be found around farms.
Classification:
Order: Charadriiformes
Family: Laridae
Genus: Larus
Species: L. delawarensis
My photos:
Ring-billed Gull, Larus delawarensis

Ring-billed Gull, Larus delawarensis at Soap Lake, Grant County, Washington State, USA Ring-billed Gull, Larus delawarensis at Soap Lake, Grant County, Washington State, USA
Ring-billed Gull, Larus delawarensis

Ring-billed Gull, Larus delawarensis at Soap Lake, Grant County, Washington State, USA Ring-billed Gull, Larus delawarensis at Soap Lake, Grant County, Washington State, USA
Ring-billed Gull, Larus delawarensis

Ring-billed Gull, Larus delawarensis at Soap Lake, Grant County, Washington State, USA Ring-billed Gull, Larus delawarensis at Soap Lake, Grant County, Washington State, USA
Photos:
Ring-billed Gull

"Ring-billed Gull - - - - - - ( Larus delawarensis ) Wednesday, December 27, 2006 Above Lake Emerald, in Oakland Park, Florida -US- near Fort Lauderdale. See him LARGER."
Photo courtesy of Mc Shutter

"The Ring-billed Gull (Larus delawarensis) is a medium-sized gull. Adults are 49 cm length and with a 124 cm wingspan. They have a white head, neck and underparts and a relatively short, yellow bill with a dark ring. The back and wings are silver grey and they have yellow legs. Their eyes are yellow and their outer rims are red. This bird takes three years to reach its breeding plumage; its appearance changes with each fall molt."
Photo courtesy of HVargas
Ring-billed gull

"Muskegon Wastewater Treatment Area, Ring-billed gull, Larus delawarensis"
Photo courtesy of ER Post
Ring-billed Gulls Flying_F.jpg

"The Ring-billed Gull (Larus delawarensis) is a medium-sized gull. Adults are 49 cm length and with a 124 cm wingspan. They have a white head, neck and underparts and a relatively short, yellow bill with a dark ring. The back and wings are silver grey and they have yellow legs. Their eyes are yellow and their outer rims are red. This bird takes three years to reach its breeding plumage; its appearance changes with each fall molt."
Photo courtesy of HVargas
Ring-billed Gull - By Andy Wilson
Ring-billed Gull. Tuesday, 9. December 2008, 08:35:51. Ring-billed Gull. Commonly referred to as a seagull and is one of the most common gulls in my area. Interestingly, there is no such… Read more…
Video:
Commentary:
Floridana Alaskiana v2.5: Ring-billed gull, 18 February 2007
This is the ring-billed gull, Larus delawarensis. It is by far the most common and dominant of central Floridian gulls. And, like it’s cousin the laughing gull, it can be a remarkable pest… Read more…
Ring-billed Gull: smaller size, neat black ring around bill, long dark wingtips, yellow legs and feet. ring-billed-tucked. Here’s the Ring-billed Gull at rest. Note the fine streaking … Read more… (Ed. note: This is a great side-by-side comparrison of commonly seen western species.)
Allnmark’s birding diary: Snowy Owl and Ring Billed Gull
So onto our next slightly easier, warmer and in focus twitch; Ring Billed Gull at Helston. Not quite as tame as the Gosport bird last year (but unless it followed us home that would be hard!) … Read more…
The Birdcouple: We came, we saw, we birded
A few more photos from the day:. Mike, who knows a lot about these things, thinks this might be a goldfinch’s nest. Ring-Billed Gull, looking kind of handsome in the cold. (The photographer… Read more…
Fishing Gull « Smithsonian Migratory Bird Center’s Blog
Ed Guthro photographed this ring-billed gull with fishing line wound around its leg. It is unlikely that this bird will survive much longer if the free end of the line gets entangled. Perhaps a… Read more…