Bird Observer - The New England Birding Journal

Bird Observer

The Birding Journal for New England

December 2016

Vol. 44, No. 6

At a Glance: October 2016 Revealed

Wayne R. Petersen

Wayne R. Petersen

This month readers are confronted with a uniformly dark, swimming waterbird. Assuming this perception is accurate, identification possibilities include some species of duck, a Sooty Shearwater, a cormorant, a juvenile Herring Gull, a dark jaeger, or a Black Guillemot in breeding plumage. A close look can eliminate Sooty Shearwater by the chunky body, relatively short wings compared to the long narrow wings of a shearwater, and the pale colored bill. The relatively short neck and chunky body of the mystery bird removes a cormorant as a possibility, as does the overall brownish rather than black color tone. A juvenile Herring Gull is arguably a good possibility, but a Herring Gull would have longer and more obviously jointed wings and would not have the blocky head shape of the mystery species. A dark jaeger in this posture would have wings that appear more falcon or gull-like than the fairly straight and shorter wings of the pictured bird, and a jaeger’s wings would probably also offer a hint of some contrasting white coloration on its primaries. Additionally, a jaeger’s bill would not be pale like that of the bird in the photograph. A Black Guillemot in breeding plumage would be jet black and would possess white wing linings and a sharp-pointed bill. A duck species is the best remaining alternative.

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