Monday, September 20, 2021

Short-billed Gull

This year ornithologists declared that the bird formerly known as the Mew Gull is actually two species—Short-billed and Common Gulls. Short-billed Gulls breed across Alaska and Northwestern Canada, south almost to the United States. Common Gulls breed across Eurasia, straying only occasionally to the New World. In the winter Short-billed Gulls migrate and are common residents along our Pacific Coast—a few stragglers remain in the summer. 

The problem is that the two species are extremely difficult to tell apart—“a very complex challenge” according to bird-identification guru, David Sibley. In his blog, Sibley says “there is a lot of variation and a lot of overlap, and you should not identify one of these gulls unless multiple features align with that identification.” Further complicating matters is that Common Gulls that stray to eastern North America are a different race and look different from Russian birds that might turn up in the West. 

Playing the odds, any of these gulls seen in the Pacific Northwest are almost certainly Short-billed Gulls. The gull in this photo, which I took on 17  September 2021 in Olympia, demonstrates this dilemma. The bill is plain yellow, lacking a distinct red spot—typical of Short-billed Gulls. But the head and neck are very pale and almost streaked rather than smudged on the back of the neck—a field mark of Russian races of the Common Gull.

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