Shorebirds and warblers aren’t, of course, the only groups of birds migrating at the moment - and the excitement that greeted one particular gull species in Alaska this summer reminded me (yet again) that a bird one set of birders walks past without a second glance will cause another set near-coronaries as they sprint across whatever rough terrain lies between them and their prize. So what was the gull that sparked such interest: a full-summer, glowing pink adult Ross’s? An Ivory Gull, that gleaming white larid that to me best epitomises the far north? No, it was a species that to European birders is far less exotic and far more mundane: the noisy, ubiquitous, and thoroughly cheeky Black-headed Gull.

A mainly Palearctic breeding-species the Black-headed Gull is spreading slowly into eastern North America (breeding along the eastern Canadian coast). The first record in the US was almost eighty years ago (in Newburyport, Massachusetts) but it’s still rare enough in nearly all parts of the continent to get birders reaching for the field-guides to make sure that they’re not perhaps mis-identifying a Bonaparte’s or a pale Franklin’s. (Incidentally, the Black-headed Gull is one of the UK’s commonest gulls and is pretty much a “trash bird” - the sort of bird that along with House Sparrows and Starlings are usually “dead certs” on a day list. In a way though I quite admire Black-headed Gulls: they’re noisy and aggressive, they’re not elegant or especially beautiful, and they certainly don’t have a song worth dedicating odes to (even though ridibundus is Latin for “laughing” they actually normally give a very un-musical and raucous “keee-ahh”), but they are tenacious and successful, and in a world that doesn’t allow too many bird species to be successful you’ve got to give them credit where credit’s due.)

Non-breeding plumaged adult Black-headed Gull Larus ridibundus sibiricus
Choshi Port, Japan. 06 Jan 2006

Black-headed Gulls are pretty distinctive though: in flight at all ages look for the white blaze along the forewing coupled with a dark underwing, and red legs and blood-red bill (orangey in very young birds, but darkening quickly) with a dark tip. Summer/breeding birds actually have a notably dark-brown hood rather than a black one (a misnomer that presumably came about as this is the only small dark-headed gull commonly seen in Europe where most birds were first named and confusion with the then unknown Nearctic species such as Bonaparte’s Gull wasn’t a matter for consideration). Immatures have dark secondaries and, like many young gulls, have a dark tail band and a scattering of brown wing-coverts.

They are also very bold: this is not a gull that sits out in the middle of a vast body of water shyly looking over its shoulder at a would-be observer. If you find a Black-headed Gull whilst your eating your picnic lunch just watch out for your fingers or a white blur will take them off at the knuckle (I’m exaggerating of course, but Black-headed Gulls are easily brought closer by throwing food towards them).

The species is often considered to be monotypic, Larus ridibundus, but many authorities separate far-eastern birds into the taxon L. r. sibiricus (which would be the subspecies any Alaskan birds would belong to), based particularly on the latter’s longer bill, slightly larger size, and (suggested by Dwight in 1925) more extensive black on the primaries of both adult and non-adult birds. In my own experience (of birds in Europe and East Asia) there is too much overlap to make the bill length a genuinely useful field character for separating eastern birds from western ones - and to be honest I’m not convinced that the primaries of the latter are indeed darker.

Interestingly, though, I did note on visit to Japan in late January (when many of the images below were taken) that virtually none of the thousands of adults I saw had yet developed much more than a “shadow” of the dark-brown head feathering of the breeding plumage whilst at least half of the adults I had been looking at just a few days before in the UK were noticeably further advanced.

So how confident would you be if a Black-headed Gull was on your local lake or landfill? Hopefully the following photos, taken in a variety of locations and at different times of year, will help turn a ‘possible’ into a ‘definite’:

All photographs copyright Charlie Moores 2007.