Friday, November 20, 2015

How do you find a Franklin's gull in Florida?

By David Simpson, BirdingWithDavidSimpson.com

Every fall, Franklin's gulls leave their breeding grounds in the Great Plains of Canada and the U.S. and head down through Texas to their wintering grounds along the pacific coast of South America.  Juveniles, having never made the pilgrimage before, sometimes find themselves in Florida, on the "wrong" side of the Gulf of Mexico.  Some are swept eastward by the many cold fronts that cross the continent.  Others, upon arrival on the gulf coast of Texas, may join flocks of Laughing gulls and wander east with their new friends.  However it happens, every October and November we find a few gems hiding among the Laughing gulls that dominate the gullscape of Florida.

So, finding a Franklin's gull in Florida is as simple as finding a large group of Laughing gulls, right?  Well maybe not quite that easy, but places where Laughing gulls congregate are where you want to look.  Florida has many such places along our coasts and even landfills and inland lakes, like Lake Okeechobee.  Hundreds (sometimes as many as 20,000 or more) of Laughing gulls gather to feed and rest on beaches, parking lots, lakes, and land fills.  Now searching for a wayward Franklin's gull among 20,000+ Laughing gulls may seem a bit daunting, but I have some tips to make it a little less so.

Franklin's gulls differ from Laughing gulls in nearly every feature of plumage and structure.  Individual variation within each species confuses the issue somewhat as extremes can nearly overlap.  However,  there are a couple of shortcuts.  I finally found my first Franklin's gull in Florida at Jetty Park in Cape Canaveral on Oct 23, 2000.  Prior to that, I spent many an hour agonizing over Laughing gulls that "looked good" for Franklin's.  Does that bird have enough of a black half hood?  Is the bill small enough?  Do the eye arcs look thick enough, do they connect at the rear of the eye?  I never quite felt comfortable enough to call one a Franklin's.  The Jetty Park bird was not my first Franklin's gull.  In January of 1998, I spent eight days in Texas with Howard Adams and John Hintermister.   While looking for Mexican Crows (now Tamaulipas Crow) at the Brownsville Dump, we found a couple of Franklin's gulls.  I immediately realized two things:  1) Franklin's gull is not that hard to pick out among Laughing gulls.  2)  All those wannabe Franklin's gulls I agonized about in Florida were definitely Laughing gulls.

What tipped me off?  Why are Franklin's gulls so distinctive?  Here are some key points that I use to find wayward Franklin's among Laughing gulls in Florida.  Most Franklin's gulls found in Florida are young of the year.  Juveniles of both species are mostly brown on the head and upper parts.  Much of the brown feathers are replaced before they depart the breeding grounds.  Back feathers are gray.  The primaries are black.  The head is mostly white with some amount of black.  However the brown "panel" on the wings (retained juvenile wing coverts) allow first year birds to be easily picked out from the rest (all other ages having gray coverts.)  At this age, both species have black primaries, but only Franklin's shows white tips in the primaries.  Some Franklin's may have very little white in the tip and indeed white tips are prone to wearing off, but all Franklin's gulls that I have seen in fall have shown white tips.  On the contrary, no first year Laughing gulls, and I have looked at thousands of them, have shown any white at all in the wing tips.  While scanning through a sitting flock gulls, look for the distinct half hood of Franklin's gull along with the thick white eye arcs connecting at the back of the head.  This is the feature that jumps out at me first.  Some variant Laughing gulls may mimic these features, but once you see a real Franklin's gull, you will realize that the others were just pretenders.  If you are not sure if it is "Franklin's" enough, it is a Laughing gull.  Franklin's gull sports a clean white hind neck, not the mottled gray neck of a Laughing gull.  The whiter hind neck further sets off the distinct half hood in Franklin's.

Eureka!  You have found a bird with a distinct half-hood, bushy eyebrows connecting at the back of the eye, and white-tipped primaries, a Franklin's gull!  Congratulations.  Now take the opportunity to observe how the other features differ from the more common Laughing gulls.  Note how the bill is smaller and lacks the slight bulge on the tip of the maxilla (upper bill) shown on Laughing gulls.  The maxilla and mandible of Franklin's gulls are similar in size and shape.  The head of Franklin's is smaller with a shorter, more rounded forehead.  Legs and wings of Franklin's are shorter than Laughing, giving Franklin's a distinctly smaller look.

Forget about picking a Franklin's gull out of a group of flying Laughing gulls, right?  Well, maybe not.  In some ways, it is easier to pick out a Franklin's gull when the birds are flying.  Did I mention that Franklin's gulls have shorter legs and shorter wings than Laughing gulls?  When I found my first Franklin's in Florida, on the beach with a bunch of Laughing gulls, it promptly walked behind the other gulls and disappeared.  No field marks work well on a bird you cannot see.  Franklin's gulls find it much harder to hide in a constantly shifting flock.  Now you see me, now you don't, now you see me again, etc. etc.  So don't ignore migrating or moving flocks of gulls or give up when an eagle or a Peregrine falcon flushes the sitting birds you were just scanning through.  In flight there are even more features to look for.  The head pattern and whitish hind neck of Franklin's is still the most striking feature, at close range.  In flight, the underside of the wings and flanks are visible.  Franklin's gulls show clean white wing linings and flanks versus mottled gray in Laughing gulls.  The wings of Franklin's gulls are noticeably shorter and rounder in flight.  Both species show a dark subterminal band on the white tail.  On Franklin's gulls, the outermost tail feathers are white, so the band does not continue to the edge of the tail as it does in Laughing gulls.

Later in winter, Laughing gulls begin molting into the black-headed garb of summer.  Some might even have full black heads by early January.  These transitional birds may go through a phase where they mimic the half-hooded look of Franklin's gulls.  The brown panel of juvenile wing coverts is replaced by gray as the birds approach their second spring,  The white tips on the primaries of Franklin's gulls may wear off by late winter.  Thus, some of the more eye-catching differences in plumage are less striking in late winter.  Structural and other plumage differences remain, however.  Also note that adults of both species have gray wings and white tips on the black primaries.  Structural differences become even more important in identifying adult Franklin's gulls in fall and winter.  Most Franklin's gulls are gone from Florida by December, but a few may stick around.  I once saw a second year Franklin's gull, by itself, on Lake Okeechobee in April.  The white primary tips had worn off and the brown panel had been replaced by gray.  Structural features were not quite as noticeable without any Laughing gulls standing nearby.  I had to resort to the internet to figure that one out.

Hopefully these tips will help you pick out Franklin's gulls from among the 1000's of Laughing gulls in Florida.  Once you get some practice, you might be surprised at how many you find.  Franklin's gulls will still be uncommon, but not so mysterious as before.

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