In On the Move, our regular column about migration, we present pairs of distribution maps from eBird that you can use to compare where interesting birds are at different times of the year. We featured Philadelphia Vireo, pictured above, in our May/June 2019 issue.
The most northerly of the vireos, the Philadelphia Vireo inhabits early- to mid-successional deciduous groves, such as aspen stands, in the boreal forest of Canada and portions of the northern lower 48 states. In June, the species nests from the border of British Columbia and Alberta east to the Atlantic and rarely in the Turtle Mountains of North Dakota, portions of northern Minnesota, Wisconsin, and Michigan, the Adirondacks of New York state, and northern New England. During the non-breeding season, Philadelphia Vireo prefers second-growth and edge habitats in Central America. The species is most readily seen during migration. It easily can be confused with the visually similar Warbling Vireo or, during breeding, with the Red-eyed Vireo, whose song, a series of short, variable phrases with a one- to two-second pause between each, is nearly identical.
eBird is the real-time online checklist operated by the Cornell Lab of Ornithology and Audubon. “On the Move” is written by eBird’s Garrett MacDonald, Chris Wood, Marshall Iliff, and Brian Sullivan. Submit your bird sightings at ebird.org.
A version of this article appeared in “Birding Briefs” in the May/June 2019 issue of BirdWatching.