Fall Equinox – Chestnut-sided and Tennessee Warblers
On the first day of Fall, a small feeding flock of migrating birds paid a quiet visit to the trees around our house. It was a cloudy, very warm and very humid day, with blue sky breaking through the big gray clouds now and then. The musical trill of a Pine Warbler’s song, and the sweet, repeated puh-weee of an Eastern Wood Pewee set the mood of the day.
Late in the morning, an Acadian Flycatcher called a sharp wheet! from the edge of the woods; two female Ruby-throated Hummingbirds chased each other off and on around the feeder; two Carolina Wrens sang back and forth; a Red-bellied Woodpecker whirred; and then the call of a Downy Woodpecker and the chatter of Titmice and Chickadees announced the arrival of a feeding flock of several different species of birds.
Except for the Titmice and Chickadees, most of the birds were migrants passing through on their way south, and most were moving and feeding quietly. A Black and White Warbler crept down the trunk of an oak and along its branches; a sleek-looking male Scarlet Tanager lurked deeper in the oak leaves, black wings contrasting with its yellow-green plumage; a Red-eyed Vireo made its way from branch to branch, eating caterpillars; and a tiny, rather plain-looking greenish warbler with a yellow throat and breast, very faint, indistinct wingbars, dingy white under the tail, and a pale streak over the eye fluttered in the leaves like a butterfly – a Tennessee Warbler.
At least two Chestnut-sided Warblers hunted in clusters of oak leaves at the ends of branches. With smooth green head and back, rich yellow wing bars, white eye-rings and no trace of the chestnut sides of their spring plumage, they looked bright and neat, and moved quickly. I watched one as it ate a green caterpillar – these green caterpillars in the oaks are popular. It hit the caterpillar against a branch once or twice, almost lazily, and then snapped it down quickly. At one point, it moved into a ray of sunlight that turned its greenish head and back to gold. Calling out a soft cheff! as it moved, it fluttered in a cluster of leaves near the hummingbird feeder, and one of the female Hummingbirds zoomed up aggressively and tried to chase it away, but the warbler ignored her, and only flew on to another tree after another caterpillar or two.
While the Tennessee Warbler moved mostly in the shadows, deep in the leaves, almost completely quiet, the Chestnut-sided Warblers looked sunny, lively and gregarious, even in their more subdued fall plumage, coming out into the open much more often.
The day ended with a break in the clouds and then, paradoxically, an unexpected but very welcome rain shower that fell steady and strong for a half-hour or more, much of the time raining through sunlight.