He pressed his head and chest up close to the crumbling bark. Pulling his stiff tail feathers up under him in an acute angle, his rear end stuck out. Then with a little hop, he hitched himself up the tree.

The process repeated itself over and over, as he leaned on his tail and then hopped with both feet an inch or so up the tall stump. The individual movements seemed herky-jerky, but the overall effect was just the opposite. He was making smooth progress, climbing and circling the dead tree while searching for insects.

At just one ounce, the downy woodpecker (Picoides pubescens) is North America’s lightest as well as its smallest woodpecker (6-7 inches).

His diminutive size seemed to be inversely proportional to his energy level. He was busily working his way up the dead stump, stopping every few inches to give the rotting bark a sharp rap. Using his long tongue, with its barbed end and sticky surface, he probed for insects and larvae.

Judging by the frequency of his visits to the old mulberry tree in recent weeks, he must have found plenty to eat here. And he was not alone. A female has become a common visitor, too.

The stump sits 20 feet outside my window. Several years ago, the mulberry sustained major damage in a winter storm. Rather than cutting it down in a conventional fashion, we had topped it off at about 8 feet.

We attached a bird feeder filled with sunflower seeds, and the usual array of backyard birds was quickly upon it. For years it has fed a steady stream of sparrows, finches, cardinals, titmice and chickadees. Now that the tree is decaying, the woodpeckers have arrived as well.

With its proportionately small bill, the downy woodpecker’s face is quite close to the wood it’s striking. From my close vantage, I could see a conspicuous tuft of tiny feathers at the base of the bill. They protect the nose from flying wood chips. None of the other woodpeckers have evolved this simple design solution to a basic functional problem. But then again, their beaks are longer!

Downy woodpeckers excavate their nests in trees, usually dead ones. Both sexes build the nest, an annual ritual, and care for the young. It takes up to two weeks for the eggs to hatch and another three weeks before the birds are ready to leave the nest. The young will be ready to breed the next year.

Woodpeckers are noted for their drumming—the rapid-fire beating of their hard beaks on resonant surfaces, usually hollow limbs. They drum to lure mates and declare territorial boundaries.

The drumming patterns vary among different woodpecker species. The downy’s cadence is a little slower than others, almost slow enough to count the individual strikes. They will do so in bursts, pausing a few seconds between drums, reeling off a sequence 10-15 times a minute.

As the bird outside my window illustrated, this is not how they obtain food. That’s more exacting work. Foraging is done slowly and deliberately. And because it’s not usually done on a hollow surface, it’s also much quieter.

Viewed from underneath, downy woodpeckers are exclusively white, from chin to tail, including unmarked flanks. From the top, though, they present a complex study in black and white.

The head has a black cap, resting atop a white stripe (ending in red in the males). That’s followed by another black stripe that begins with the eye, bulges slightly at the bottom before tapering to a dainty juncture at the back of the head where it meets the stripe from the other side and a thin perpendicular line running down the back of the bird’s neck. Next is a second white patch. This starts as a narrow band just over the bill that curves below the eye and expands to cover most of the back of the neck before looping around toward the breast. And finally, there is yet another black stripe. This one starts at the base of the chisel-like bill, running in a narrow streak down and back to a black patch on the side of the neck before reversing direction, ending in a point facing down and toward the front. And that’s just the head!

In the field, one of the most distinctive features is a bright white patch in the middle of the small bird’s otherwise black back. The wings have a handsome checkerboard pattern. Those sturdy tail feathers are black, edged in white with a couple of black dots to complete the picture. Its overall pattern is a near replica of its larger cousin, the hairy woodpecker (Picoides villosus).

I spend many hours here in our study, pecking away at the computer and scratching out letters. Now and again, I lift my gaze to the winged world just outside my window. On this day, my eyes had settled on a downy woodpecker, a bird that transforms simple black and white into an elegant design and uses its diminutive gifts to inject new energy into a lifeless old stump.

I swung back to my work and hit the ‘print’ key. Staccato bursts of the laser jet sprayed black words onto white paper that steadily crept out of the printer. I peered at the words on the page, wondering if a bit of the downy woodpecker’s elegance would survive the translation.