ALWAYS IN SEASON/ MIKE JACOBS: Woodpeckers exploit habitat niches
The downy woodpecker is not the most conspicuous member of its family, but it is the commonest woodpecker in our area. That doesn't mean it is the most often encountered. The downy woodpecker is the smallest woodpecker occurring in North America,...
The downy woodpecker is not the most conspicuous member of its family, but it is the commonest woodpecker in our area.
That doesn't mean it is the most often encountered.
The downy woodpecker is the smallest woodpecker occurring in North America, and it is not as noisy as some other woodpecker species. Also in contrast to some other woodpeckers, the downy woodpecker is not boldly colored.
It is not a shy bird, however. For the most part, it is tolerant of people. Downy woodpeckers nest and raise young in backyards and come to bird feeders, especially those offering suet.
Yet, the downy woodpecker is easy to overlook. It is not a bold, brash bird. It lacks the drama of the pileated woodpecker, the largest in our area. Nor does it have the vivid plumage color and pattern that pileated and red-headed woodpeckers display.
It's just a much more subtle bird.
Nevertheless, encounters with downy woodpeckers can be surprising and therefore memorable.
One such occurred on a cold, clear morning last week. I'd gone out to fill the feeders, and when I turned away, I realized I was not alone. A downy woodpecker was perched scarcely a foot away. I'm not conscious of having seen or heard it; I simply noticed it.
Something similar happened later in the day, when I noticed another downy woodpecker on a sunflower stalk standing in the garden. This bird gave a little cheap, an alarm note, I assume, and flew off.
These were different birds, I know, because downy woodpecker males and females can be separated by sight. The feeder bird was a female. She lacked any red in her plumage. The afternoon bird had a red patch on the back of his head, a male.
The birds were exploiting different food sources, both of them taking advantage of foraging opportunities presented by the resident human.
The downy woodpecker is one of four woodpecker species that regularly occur at our place west of Gilby, N.D., and each of them have different feeding habits. The northern flicker, common in spring and fall, forages on the ground taking ants and grubs. The yellow-bellied sapsucker feeds on tree sap it takes from sap wells it creates. Hairy woodpeckers come to feeders in the winter, but I never see them in the garden. Instead, they forage in the shelterbelts.
Hairy woodpeckers are larger than downy woodpeckers, though they otherwise are nearly identical. A sunflower stalk won't bear the extra weight.
This isn't the end of woodpecker specialization, however. Among downy woodpeckers, males are more likely to be found in weedy patches; females more often forage in copses of small trees.
Downy and hairy woodpeckers present an identification challenge. Although hairy woodpeckers are larger, the two species otherwise are nearly identical in appearance.
Size isn't a good field mark because it's hard to judge accurately. Still, it is more reliable than the common names of these two species, which refer to the white stripe on the back of the birds. This is most visible when the birds fly. It's downy in the smaller species and more like hair in the larger. So the bird books say. There's an alternate theory that downy woodpeckers are so-called because their nostrils have tiny hairs. These are not details that casual observers are likely to notice.
The best way to tell the two species apart is the size of their beaks. Downy woodpeckers have rather small bills in proportion to the size of their heads. In hairy woodpeckers, the bill is nearly as long as the head itself, and it looks heavier than the delicate bill of the downy woodpecker.
This difference leads each species to a different foraging strategy.
Like others in the family, downy woodpeckers are cavity nesters, and they do their own excavating. Woodpecker activity has an important impact on local habitats. For example, the sap wells that sapsuckers create attract a range of other species, ranging from ants to butterflies as well as other birds. Similarly, mice and small birds move into holes that woodpeckers have excavated.
These four species are regulars at our place. Three other woodpecker species occur in the Red River Valley. The pileated woodpecker is near the western edge of its range here, but the species seems to be increasing and expanding to the west, perhaps in response to a sudden supply of dead timber, the consequence of Dutch elm disease and flooding at Devils Lake. Red-headed woodpeckers are dependable here, too. These species are conspicuous and familiar, though neither is common here. The red-bellied woodpecker is a relative newcomer. It's moved into the area from the southeast.