In our migration column “On the Move,” we present species distribution maps from eBird for specific time periods so you can compare where birds are at different times of year. One of the birds featured in our June issue is Vaux’s Swift, the western cousin of Chimney Swift.
Vaux’s Swift migrates each year in April and May from wintering areas in Mexico and Central America to the Pacific Northwest. The eBird maps above show the bird’s location in January (left) and May (right) from 2009 through 2013. In January, the swift occurs in two somewhat overlapping populations: birds that live year-round from central Mexico to Panama and northern Venezuela, and migrants that winter from southern Mexico to Honduras. (The few purple squares in southern California and Louisiana represent rare winter records.) In the first half of May, small groups of swifts push through southern California and across Arizona; by late May, the birds reach breeding areas stretching from northern California to southeastern Alaska. In migration, flocks are often seen with swallows over ponds, lakes, or rivers. Listen for their high-pitched, rapid twittering calls as they zip overhead.
A version of this article appeared in “Birding Briefs” in the June 2014 issue of BirdWatching. Subscribe.