Saturday, January 7, 2012

Franklin's Gull

Yesterday, on our third trip to Black Dog Lake, Erika and I found a much-reported Franklin's Gull. With its black-smudged head and white-spotted primaries, identification is fairy clear. The trouble is that this gull should be wintering in the Pacific Ocean off the coast of western South America (mostly off Peru and northern Chile). A look at eBird demonstrates that December through February records in the United Stated are sparse, limited to coastal areas and scattered through the central states.

This species breeds in prairie marshes in the upper Great Plains. They can be abundant during migration as they follow farm machinery that turns up insects. They feed both in the air and on the ground. Franklin's Gulls often abandon disturbed breeding colonies and are subject to the unpredictability of prairie droughts. Their numbers, therefore, often fluctuate. Recently only 36 breeding locations were counted in Canada and 21 from the United States. Colonies can contain over 10,000 pairs (Burger and Gochfield 2009).

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