A Connecticut Warbler pauses on the ground before its Atlantic crossing

A Connecticut Warbler (Oporornis agilis) turned up on September 11 on a restricted-access property along Posquiello Creekside Road, a single bird working the ground cover.¹ It is one of the least-seen warblers in the East. Most birders who have one on their list found it this way, on a fall stopover in the Northeast, and never on its breeding grounds in the tamarack and spruce bogs and jack pine stands of the boreal forest.

It is a plump, short-tailed warbler with a gray hood, an olive back and a yellow belly. The mark that catches the eye first is the eye-ring: complete, white and bold. The legs are long and pink, the bill is heavy and spike-like, and the feathers under the tail run nearly to its tip. Mourning Warbler is the lookalike. It is slimmer, its eye-ring is broken or missing, and a male in spring carries black on the breast where the Connecticut is plain gray. Nashville Warbler has a similar eye-ring but a yellow throat, is much smaller, and feeds up in the trees.

The surest tell is how it moves. A Connecticut Warbler walks. It paces slowly along the ground or a low branch, bobbing its short tail, and flips dead leaves to get at the insects underneath, the way an Ovenbird does. Nearly every other warbler hops. On stopover it keeps to the bottom of the understory: weedy field edges against woods, thickets, tangles of goldenrod and jewelweed. Whoever is looking for one is looking at the ground, not the canopy, and usually waiting a long time.

The bird's migration runs in a loop. In spring it comes north through the middle of the continent. In fall it swings east to southern New England and the Atlantic coast, and from there it flies out over open ocean. In 2017, researchers fitted geolocators to birds breeding in Manitoba and later recovered four of them.² The tracks they read showed roughly 48 hours nonstop over the Atlantic, some 1,700 to 2,400 kilometers, to Cuba or Hispaniola. The birds then spent about a week on the ground there. From there they crossed another 800 kilometers of water to Venezuela and continued on to wintering grounds in the Amazon basin. The bulk of the species passes through the Northeast in the second half of September.² A bird on the Hudson on the 11th is on the early side of that window, feeding in the leaf litter before the long overwater leg.