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 year. We’re featuring Alder Flycatcher, pictured above, in our June 2015 issue.
Alder Flycatcher is one of the 11 notoriously confusing species of the genus Empidonax. The maps above show where eBird users reported it in June and October over the last 10 years. The flycatcher is a late-spring migrant, moving north through the central and eastern states from mid-May to early June. It migrates from South America and nests in shrubby wetlands, bogs, and damp woods in the areas shown in purple on the June map: in the boreal forests of interior Alaska and Canada and in the northern lower 48 states. The flycatcher is easiest to detect in spring and early summer, when it sings fee-bee-o, its distinctive song. In late August, September, and early October, when the bird is heading back south, it rarely vocalizes, making it difficult to distinguish from other empids. Your best bet to ID it then is to learn its call note, a short pip.
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 June 2015 issue of BirdWatching. Subscribe.Originally Published