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 Connecticut Warbler, pictured above, in our May/June 2019 issue.

Named by Alexander Wilson from an individual collected during fall migration in its namesake state, the Connecticut Warbler is not common there, instead breeding (in June) across a broad swath of the Canadian boreal forest and in southerly extensions of boreal habitat in northern Minnesota, Wisconsin, and Michigan. Pairs nest in remote spruce and tamarack bogs, places that are difficult to get to and often full of mosquitoes, which has led to their being poorly known to this day. During the nonbreeding season, the Connecticut Warbler is found primarily along the western edge of the Amazon Basin, where it is extremely poorly known (see the January eBird map from the past 10 years). In the spring, listen for the distinctive, ringing song of the male, a repetition of two- or three-part phrases. The species is shy and skulking, much more often heard than seen, but careful observers may glimpse a compact, short-tailed warbler with a bold, complete eyering.
See eBird’s real-time distribution map for Connecticut Warbler.
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.