Laura Erickson's For the Birds

(Recording of a Black-and-White Warbler)

When I set out to become a bird watcher in 1975, the very first warbler I identified was the Black-and-White. This aptly-named bird is striking proof that beauty is a matter of design, not color. The adult male gleams black and white in a bold pattern with no shades of gray to dull the effect. Even after a long Northland winter when we hunger to see the bright colors of orioles, tanagers, and other tropical birds, the elegant Black-and-White Warbler is still a joy to behold. The female’s beauty is more subtle, with soft browns on her cheeks and flanks, yet even she has a unique and soft loveliness. As if to aid our appreciation, these elegant little birds feed mainly on the trunks and large, low branches of trees and shrubs, in the manner of creepers or nuthatches, and so they are often seen at or below eye level. They move along twig or trunk with a switching motion, tail sweeping from one side to the other.

The Black-and-White Warbler has a distinctive song, though it’s so high-pitched that it’s above the hearing range of some people. It’s a simple, unhurried series of about 6-8 couplets, often transcribed as “wee-see, wee-see, wee-see, wee-see, wee-see, wee-see.”

(Recording of a Black-and-White Warbler)

Black-and-Whites are among the first of all warblers to return in spring, mainly because they are well adapted to gleaning their insects from the bark of trees and shrubs, and don’t need to wait for leafing out to find their food. They eat a wide variety of small insects, along with spiders and daddy-long-legs. Although they can be found in woodlands throughout Wisconsin and eastern Minnesota, they are most common in north country, especially in moist woodlands.

The name for their genus, Mniotilta, means moss plucker in Greek, though they are more likely in my experience to be plucking at the insects within the moss-lined tree bark than at the moss itself. The Black-and-White Warbler nests on the ground, usually at the base of a tree or shrub, often hidden under an arch of dead leaves. Once the four or five babies fledge 8-12 days after hatching, they perch on tree limbs where their parents feed them. When they mature and set off on their own in mid-summer, they each join a different loose flock of warblers, kinglets, chickadees, and nuthatches—normally there is no more than one Black-and-White Warbler per flock.

They mosey on south for the winter at a leisurely pace—some go no further than the Gulf states, but others go as far south as Ecuador and Venezuela. Their unhurried pace throughout their lives is perhaps the secret to their longevity—banded birds have been recorded surviving for as long as 11 years, which seems incredible when you consider how tiny they are—they normally weigh only a quarter of an ounce, meaning you could mail four of them with a single postage stamp. And even well fattened ones ready to migrate weigh a mere half ounce. The well-known ornithologist Alexander Sprunt wrote, “Were all the members of this puzzling, provoking, and altogether delightful avian family as readily recognized as this one, how much of doubt and confusion would vanish, and, one might add, fascination!”

(Recording of a Black-and-White Warbler)

This is Laura Erickson, and this program has been “For the Birds.”