Laura Erickson’s For the Birds

Right now is the time to start looking and listening for early migrants. In forests, parks, and old neighborhoods with large trees, you might spot a Brown Creeper, the only member of the family Certhiidae in the Americas. This attractive, slender songbird is cryptically colored to match tree bark. It has a delicate but relatively long bill, curved downward to pick out tiny insects in crevices in the tree bark; and long, stiff, tail feathers that curve downward from the other end to brace it against tree trunks. Its hind toe bears a long, strong claw providing an additional brace to help the bird hitch its way up tree trunks.

The Brown Creeper’s lovely, high-pitched sound is beyond my hearing now unless I crank up my hearing aids to eleven and the creeper is very close. Losing its calls and songs is one of the bitter tragedies of old age, but well offset by the joy of still being alive and able to see these beloved sprites.

I saw my first Brown Creeper on December 16, 1975, at the Morton Arboretum outside Chicago. The next month, on January 30, 1976, I saw my first for my Michigan list at Baker Woodlot on the Michigan State University campus, and by February, according to my field notes, I was recognizing the tiny mites by sound. It wasn’t uncommon at all for them to overwinter in Lansing, Michigan, or Madison, Wisconsin. Rarely, one may even overwinter in Duluth or the Sax-Zim Bog, but we usually find our first up here in late March or early April.

Brown Creepers live up to their name, creeping up tree trunks, often in an upward spiral, until they encounter too many branches, when they flutter down to a low spot on another tree and creep up that trunk. If they continue up a limb, they gravitate to the underside.

Arthur Cleveland Bent put together a wonderful series of books about the life histories of North American birds, and gave Winsor Merritt Tyler the honor of writing the Brown Creeper entry. He opened it with this superb description:

The brown creeper, as he hitches along the bole of a tree, looks like a fragment of detached bark that is defying the law of gravitation by moving upward over the trunk, and as he flies off to another tree he resembles a little dry leaf blown about by the wind. As he climbs up the tree, he is feeding, picking up tiny bits of food that he finds half-hidden in the crevices of bark along his path. In his search, he does not work like the woodpeckers, those skilled mechanics whose work requires the use of carpenter’s tools, the drill and chisel. The creeper’s success depends on painstaking scrutiny, thoroughness, and almost, it seems, consciousness. Edmund Selous (1901), speaking of the European tree-creeper, a bird close to ours in habit, uses the exact word to show us the creeper at work. “His head,” he says, “which is as the sentient handle to a very delicate instrument, is moved with such science, such dentistry, that one feels and appreciates each turn of it. (end quote)

Creepers seem as earnest and focused as they are sentient, and as introverted as songbirds could be. Occasionally during migration, I spot two or more in the same swath of woodland, and they often associate with chickadee feeding flocks, but they hang out on the periphery of the flock, never in the thick of things, and often when the flock moves on, the creeper may linger. It’s only in their nesting woods that we’re likely to see two near each other, and even then, except when doing their charming courtship flights, they stay focused on their own work, like a couple who may be deeply in love but spend most of the day in separate work places.

But even the most introverted among us fall in love, creepers included. I’ve only seen a courtship flight a handful of times in my life. Winsor Tyler describes it beautifully and accurately:

Once in a while we see a bird launch out from a tree and at top speed twine around it close to the bark, then dart away and twist around another tree, or weave in and out among the surrounding trees and branches. He has thrown off his staid creeper habits and has become for the time a care-free aerial sprite, giving himself up, it seems, to an orgy of speed, wild dashes, and twists and turns in the air. But after a round or two, back on the bark again, he resumes his conventional routine and becomes once more a brown creeper. (end quote)

Bird observers in the early 1800s claimed the Brown Creeper nests in cavities, but in 1879, Thomas Brewer wrote that the normal nest, as with the European creeper, is built between a tree trunk and a flap of partially detached bark. Sure enough, the next spring, William Brewster used that tip to search trees near Lake Umbagog in Maine and discovered quite a number of nests.

On May 1, 1976, Russ and I went on a Michigan Audubon trip that included a nice long stop at Hartwick Pines State Park, where my birding mentor Joan Brigham found a Brown Creeper nest. It was the loveliest thing, exquisitely concealed on the truck of a huge white pine, the hammock-shaped nest woven of bits of bark, fuzzy material such as spider silk, and Usnea lichen wedged where a large piece of bark was jutting out. The pinkish-brown-flecked white eggs hadn’t hatched yet, so I’ve never seen a nestling, and when they fledge, creepers are so quiet and cautious that I’ve never seen a fledgling, either. Winsor Merritt Tyler wrote of one brood:

Whenever I saw them as a silhouette against the sky, and could thus determine the point, they did not use their tail for support. The shortness of the young Creeper’s tails gave to their bodies a rounded, unbird-like outline and, with their short, stubby bills of wide gape and their squatting position on the upright bark they suggested tree-toads in no small degree.

As lovely as it is to see Brown Creepers in lush old-growth forests, there’s something special about the ones that I see in my own backyard. Next time I’ll talk about falling truly madly deeply in love with one individual Brown Creeper.