Age: Whichever species this is, we can be sure it's a subadult based on the black centers to the secondaries and dark smudging on the underside of the primary coverts.
Identification: This is a hooded gull with thick white eye crescents and a relatively stout bill. The broad white trailing edge and dark wingtip readily eliminate smaller species such as Bonaparte's and Black-headed (so-called "masked gulls" which have mostly gray along the trailing edge of the secondaries).
The only expected hooded gulls in North America are Franklin's and Laughing. One may assume this is a Laughing Gull based on the time of year and location, but taking a closer look, we can make the case for Franklin's for the following reasons: The eye crescents are rather wide and the hood is sharply demarcated with a clean, white neck. And more importantly, the active molt in the primaries is expected in Franklin's at this time of year (note the 3 new innermost primaries). Franklin's undergoes two complete molts per annual cycle. During the northern winter, this species is typically found in South America where it undergoes a complete prealternate molt, replacing body and flight feathers at once. This individual appears to be doing just that, presumably via its 1st prealternate molt.
A few Franklin's Gulls can be found lingering in North America in the boreal winter, primarily in the far south. Those that winter north of the equator appear to average less extensive prealternate molts than their southern counterparts. Here is this individual with several Laughing Gulls.
|Franklin's Gull (center) typically shows a semi-hood if not sporting a complete hood. It averages a smaller body and bill than Laughing Gull. Note how the eye crescents "pop" on the darker head.|