Tiny, colorful birds flit through our trees during spring migration, snapping up caterpillars and other small insects to feed their frenetic lifestyle. As brilliant as parrots, in many cases, this family of birds is known as the wood-warblers.
And they just may be the best kept secret in the bird world. Back when my husband and I were neophyte bird watchers, we were talking with a more expert friend. "How many warblers have you seen this spring?" he asked, and we looked at each other in wonder. We'd never even heard of warblers, but once we began watching for them, spring was filled with much more color and activity. And we encountered an unforeseen side effect: So many warbler species work in the upper tree canopy that straining to watch them causes a well-known malady — warbler neck.
Minnesota is the summer home for around 25 warbler species, birds that seldom hold still and carry tantalizing names like redstart, black-throated green, cerulean and chestnut-sided warbler. Some of the smallest birds on the continent, warblers are designer birds, adorned with bright heads, throats, chests or wings, or, in some cases, all of these. Warbler watchers look for flashes of bright yellow, blue, orange or cinnamon brown, plus dramatic patterns around eyes, on wings, chest or back. (However, there are some plain birds in the family, such as the olive drab orange-crowned warbler.)
They're an ephemeral phenomenon of spring. The first to arrive are the yellow-rumped warblers, migrating in from Central America and the Southeast. This handsome little bird with its distinctive yellow-patched rear causes great excitement in the birding community when the first few are reported in late March — this means that the rest of the warblers are on their way.
What starts as a trickle builds, as trees start leafing out, to a wave as black and whites, common yellowthroats, Nashvilles and Blackburnians dash in, just as caterpillars are hatching and beginning to feast on spring's tiny leaves. This is what warblers are built for, with pointed, tweezer-like beaks, ideal for snatching up squirmy insects. Soon the whole clan is in town, from prothonotaries to blue-wings to yellows to magnolias.
Sound more like insects
As for their family name, warblers don't warble at all and in fact, they often sound more like insects. They mostly emit buzzy trills, but some burble lovely notes, such as the Northern parula, which seems to have listened to "The William Tell Overture" at some point.
And suddenly, by mid-June, they'll be gone, heading for northern forests where massive hatches of insects make it easy to keep nestlings fed during the short breeding season. But we can still observe the warblers that nest around us, including American redstarts, yellows, prothonotaries, ovenbirds and common yellowthroats.
Because they're so focused on insects, warblers are seldom seen at backyard bird feeders. However, during very cold springs, when insects are scarce, a few may peck at suet or small pieces of fruit.
