Laura Erickson's For the Birds

Downy Woodpecker

On Superbowl Sunday morning, I filled my bird feeders to the sound of a Downy Woodpecker drumming on my maple tree. I was so focused on the bird that it didn’t even occur to me that the sound presaged a bunch of New Englanders hammering some Eagles. Fortunately, football isn’t my forte—a Downy is far lovelier than any first down, and I’d rather see a Fieldfare than a field goal or a Canvasback than a quarterback any day. So my thoughts stayed pretty squared on the Downy Woodpecker, even though a Downy, weighing less than an ounce is outweighed by an official football by a factor of 15, and the little woodpecker flies through the air slower than a football player’s top speed of about 22 mph, to say nothing of the speed of a well-kicked or thrown football.

Downy Woodpeckers were given their scientific name, Picoides pubescens, in 1766 by Carolus Linnaeus himself, even though he never saw one in his life. Linnaeus based his binomial name on the common name given to the bird by the American colonial naturalist Mark Catesby. Catesby, who examined museum specimens and birds he shot himself, named the bird for the downy soft white feathers of the lower back, which were noticeably different from the more hairlike corresponding feathers on the Hairy Woodpecker. This of course isn’t a very useful feature for distinguishing the two in the field, but in those days before binoculars, features evident in the hand were considered more useful than any field marks—back then there wasn’t even a term for field marks. We distinguish Hairy and Downy by size—the Hairy is noticeably bigger, but in particular the Hairy has a large beak, as long as its head, while the Downy’s beak is much daintier. Also, if you get a good look, a Downy’s outer tail feathers have black barring while a Hairy’s outer tail feathers are pure white. And the Hairy’s sounds are louder and more robust.

This time of year, the increasing day length gives these little woodpeckers ample time for foraging and feeding on an adequate number of calories with minutes to spare, and as they get twitterpated, the males spend most of that free time drumming. As pair bonds form this month and next, mated Downy’s will start spending more and more time together, though they don’t normally excavate a nest cavity and start laying eggs until late April or May up here in the north. Downy Woodpeckers typically make their nest hole in a dead tree or snag, with both the male and female sharing construction duties. Both sexes develop a brood patch and fairly equally divide incubating duties during daytime; the male is the one who sleeps with the eggs at night while the female retreats to her own private cavity at nighttime. The buildup of carbon dioxide in a nest cavity compared to an open nest makes oxygen transport through the eggshell to the embryos more difficult, so woodpeckers have a significantly shorter incubation period than open nesters. That means the babies hatch out while more helpless and undeveloped than most nestlings. Their small size, coupled with the intensity of feeding by the adults, allows hatchling Downnies to often double their weight their first day out of the egg.

Downy Woodpeckers have the curious habit of associating with their huger relative, the Pileated Woodpecker. Apparently the Downies pick through the larger woodpecker’s fresh excavations to pick up little insects the Pileated missed. And so that a pair can more efficiently glean a large amount of prey from their small territory, the male and female specialize in their duties, males usually foraging on smaller branches and stems while females spend more time on the trunks of trees. This specialization, I suppose, is somewhat akin to the specialization of people out there on a football field, the males apparently foraging nearer to the pigskin while the females forage using a peculiar tool called the pompom, which brings us full circle back to Eagles and Patriots and TV commercials, the very thought of which makes me impatient to get outside and clear my head listening to a twitterpated Downy Woodpecker.