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.
As these small, vibrant birds pass through our area briefly each spring, I'd advise grabbing a pair of binoculars, heading outdoors and looking up at tree canopies anytime between early April and mid-June. Even if they cause a sore neck, warblers are some of the bird world's little-known wonders, always rewarding to see.
St. Paul resident Val Cunningham, who volunteers with the St. Paul Audubon Society and writes about nature for local, regional and national newspapers and magazines, can be reached at valwrites@comcast.net.
Yellow-rumped warbler
Size: 5½ inches long.
Fact: Cold-hardy birds, the first to arrive in spring, among the last to leave in autumn.
Watch for: Distinctive yellow rump patch earns it the nickname "butter butt."
Yellow warbler
Size: 5 inches long.
Fact: Nests in our area and sings from outer branches, making it easy to spot.
Listen for: One of the best songsters, with its "sweet, sweet, I'm so sweet" song.
Cape May warbler
Size: 5 inches long.
Fact: This good-looker often appears during spruce budworm outbreaks Up North.
Watch for: Males have a chestnut patch on the face, streaking on a yellow chest.
Chestnut-sided warbler
Size: 5 inches long.
Fact: Nests in shrubs in northeastern Minnesota.
Watch for: Bright yellow-green cap, reddish splotches on its sides are eponymous.
Magnolia warbler
Size: 5 inches long.
Fact: This small bird has a little of everything: necklace, wing bars, eyebrows, etc.
Watch for: Often forages low in shrubs and young trees, fairly easy to spot.
Black-throated green warbler
Size: 5 inches long.
Fact: Each warbler watcher has a favorite, and this flashy little bird is mine.
Watch for: Sunlight brings out its green back, contrasting with a yellow face.
Common yellowthroat warbler
Size: 5 inches long.
Fact: Fast-moving little bird with distinctive black eye mask.
Listen for: Sings a distinctive "witchity-witchity" song, found in wetlands.
Blackburnian warbler
Size: 5 inches long.
Fact: Arrives in early May and searches for insects high in the treetops.
Watch for: Its neon-bright orange throat is unique, eye-catching.
American redstart
Size: 5¼ inches long.
Fact: Flits and fans its tail to startle and freeze insects long enough to catch them.
Watch for: Its orange and black plumage leads some to call it a "little oriole."
Northern parula
Size: 4½ inches long.
Fact: One of the smallest warblers, and often found near water.
Watch for: Bright bands of color across its yellow chest, a fast-moving bird.
Where to find them
Mornings and late afternoons are the best time to find spring's warblers foraging for insects:
Afton State Park, 6959 Peller Av. S., Hastings.
Crosby Farm Regional Park, 2595 Crosby Farm Rd., St. Paul.
Fort Snelling State Park, 101 Snelling Lake Rd., St. Paul.
Maplewood Nature Center, 2659 E. 7th St., Maplewood.
Thomas Sadler Roberts Bird Sanctuary, 4124 Roseway Rd., Minneapolis.
Mississippi River Gorge Regional Park, both sides of Mississippi River, I-35W bridge to Ford Pkwy.
Coon Rapids Dam Regional Park, 10360 West River Rd., Brooklyn Park.
Wood Lake Nature Center, 6710 Lake Shore Dr., Richfield.
