Wednesday, September 16, 2015

Swallows

With the fall season, Barn Swallows begin to head south, often join mixed swallow species flocks. On 9 September, at the 180th Street Marsh in nearby Dakota County, John Holden and I counted 26 Barn Swallows, although probably quite a few additional individuals escaped our tally. Among the Barn Swallows were a few Cliff Swallows, one Tree Swallow, and two Purple Martins, one of which can be seen in the lower photo. Martins are common enough, but I do not see many away from their nesting boxes. They are known to congregate in some areas and may make fairly direct migrations from those sites. On the other hand, eBird only shows eight Minnesota records from this September.

Barn Swallows often roost in flocks of hundreds in marshes. During migration, Barn Swallows cover from 2 to 194 kilometers per day, with greater distances covered as the fall progresses. They are trans-Gulf of Mexico and trans-Caribbean migrants. A Barn Swallow banded in New York was recovered 44 days later off Panama, which is an average of about 89 kilometers per day (Brown and Brown 1999). Although a few stragglers have been recorded in the United States during the winter, most North American Barn Swallows winter in South America.

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