The Birds of Winter, continued
with Mike Lushington
In summer, we have three species of gull in the area. Most people recognize the Great black-backed and the Herring gull, although I still encounter people who think that the black-back is the male and herring gull, the female form of the same species. They are, however, two distinct but very closely related species. There is a third species that, for most of us, may be the most commonly noticed of all in summertime, although rarely recognized as a distinct species. The Ring-billed gull is the most common gull around fast-food outlets (giving it its common nickname among birders, the "MacDonalds' gull"), shopping malls, and wherever people hang out in large numbers, especially with food nearby. ( A fourth species, the diminutive black-headed Bonaparte's gull, can often be seen along the coastline in summer - the Charlo River estuary is a favourite congregating spot - but it never comes close to those places frequented by any of its larger relatives. As well, it is altogether smaller and more dainty in appearance than any of the others - it is, in fact, more often confused with Common terns than with other gulls.)
Come this time of year, Ring-billed gulls begin to vacate the area. It has been a rare occurrence to count even one during the local Christmas Bird Counts, although both Great black-backed and Herring gulls show up in good numbers on count days and persist in the area until ice conditions drive most of them away in late January or early February. However, this is the time of year to start watching for a couple of very attractive winter gull visitors that actually do make it onto CBCs.
It was a particularly cold, blowing day in January, one day years ago. I found myself down at the Inch Arran Lighthouse. I had just begun to take birding in a serious, formal fashion, and, in common with most new converts, I took every opportunity, even the seemingly most unpromising, to look for whatever might be around. It was blowing hard; although the sky above was clear, the air at eye level was filled with drifting snow. I was just about to turn my car around and head for home when I spotted this ethereal being drifting along the cliff face in front of me, seemingly oblivious to the tumult. Right away I recognized it as a gull, but, otherwise, had no idea. I watched it for as long as I could before it faded into the snow and wind; by that time I had, I felt, enough to be able to figure out what it was. And so I did: that was my first encounter with Iceland gull. Since then, I have come to appreciate that this species is actually a common winter visitor.
Iceland gull is described in most bird guides as "a highly variable" gull - which means that it can look like a lot of things. It is about the same size as Herring gull (perhaps a tad smaller), which makes it considerably larger than most Ring-billed gulls. Adult birds can vary from almost pure white with very pale grey backs to considerably darker birds. However, they rarely show any black at all - perhaps a bit on the very tips of some of their outer primaries - although that usually resolves into dark grey if you get a chance to take a good close look. Younger birds can be very easily confused with juvenile Herring gulls, although, on average they are paler brown and, again, somewhat smaller.
And then there is Glaucous gull. This is really a special bird. I manage to see several each winter, but they are not nearly as common as Iceland. They are huge, almost as large as Great black-backed (which is the largest gull in the world), and almost always extremely pale. They are much more consistent in their plumage than are their smaller cousins and there are subtle differences to note that help with identification.
If you are planning to spend some time down around the coastline this winter, take the time to study these two birds in your guide. Both are very worthwhile additions to any birder's life list - and we live in one of the good places to spot them.