Herring Gull amidst Brant.
Great Black-backed Gull amidst Herring, Brant, and Ring-billed. Great Black-backed is the world’s largest species of gull.
Our triumvirate of winter gulls. From the top, Herring, Great Black-backed, and Ring-billed. Strays and exotica show up, and Bonaparte’s Gull is found off-shore, but these are the three standard gulls of the NYC winter. Ring-billed predominate by a long shot.
To spice things up, this is Great Black-backed in its first winter, or so I judge. Ring-billed in the background.
(A sunny day!) Ring-billed left, Herring right.
Backyard and Beyond 
In Centeral Park gulls seem to come in clumps. Ring-billed gulls predominate the north end of the park, but Herring gulls far outnumber ringers, black-backs and occasional strays like Laughing Gulls combined, on the reservoir. I doubt this sample is large enough to extrapolate any data for the region.