Pileated Woodpecker
by David Cronenwett
On a recent visit to the Swan Valley, I’m mesmerized by the dense, lush forests of deep snow country. During one of those introspective moments, driving up highway 83, a large black & white bird wings over the road. It’s always funny how seeing a species out of context can cause one to hesitate in a moment of confusion before its name comes to mind. And at present, I’m seeing a bird in a different country from my home range, where this beast is rarely found to begin with. It is large, with an undulating flight pattern and unmistakable red crest: a Pileated Woodpecker (Dryocopus pileatus).
Woodpeckers are classed in the family Piciformes and about 200 species are well distributed across the globe, except in Australia, New Zealand, Madagascar and the polar regions. Montana is home to eleven species, but none are as spectacular as the Pileated. Woodpeckers can be quite dependent on specific forest conditions to thrive. The decline and eventual extinction of the Imperial Woodpecker in Mexico and the Ivory-billed in the Southeast due to poor timber management, have made the Pileated the largest of its kind in North America. The State of Montana has listed the bird, which is sometimes used as an old-growth indicator, as a Species of Concern due to its sensitivity to industrial forestry activities. Pileated’s are found most abundantly west of the Continental Divide, but range maps show them as present in some east side ranges. On the larger scale, they are permanent residents of the Boreal north, Canadian Rockies and most of the hardwood forests of the East, South, and Upper Midwest.
The preferred food for this bird is carpenter ants. The Northern Rockies lack termites, so these insects are an important agent for breaking down cellulose. The ants seem to be especially abundant in the base of larger diameter trees that have begun to rot from within. This is where one can often find the very large, ovate-rectangular “drill holes,” diagnostic of the Pileated. Even given the bird’s substantial size, it is truly incredible how much damage they are capable of inflicting upon wood. Because they have no sense of smell, woodpeckers use their keen sense of hearing to detect insects. This may account for their habit of turning their heads to the side while clinging to trees; it may be that they are trying to get a better listen. Once an opening is created, Pileated’s use extremely long sticky tongues to extract the insects.
Research has shown that the amount of energy absorbed by a woodpecker skull from each “peck” is about one thousand times the force of gravity. In a person, exposure to this sort of abuse would quickly result in severe brain injury. But woodpeckers have come up with evolutionary answers to this problem. Pileated’s and their cousins have spongy-bone structures within the skull that help protect their brains. The brain itself has an elongated rather than round shape, which aids in diffusing energy. The angle that the birds use to drill and even slight variations in length between the upper and lower mandible, all influence their ability to withstand incredible amounts of stress. Researchers have been studying woodpecker anatomy in the hopes of creating better head protection devices for human use.
New nests are created yearly, and because of the large size of the Pileated, big trees, preferably standing dead ones, are necessary for nesting. Both parents will incubate eggs and rear the young. Woodpeckers perform a huge service to other species by excavating cavities that many other birds and even some rodents take advantage of for nesting sites. The iconic Mountain Bluebird, for example, experienced a serious population decline a few decades ago, partly because of the widespread removal of the large dead snags that woodpeckers prefer.
On the East side of the Rockies, I’ve observed plenty of Pileated sign but have seen far more unusual species of woodpeckers like the Three-Toed over the years. But one spring, with a group of about forty third graders, a Pileated decided to show itself amidst a stand of partly burned-over forest. It was one of those moments when you have to ask yourself, why now? I saw the bird not on one my many of solo excursions into the woods, not when intentionally seeking it out; but with a huge group of rowdy kids. Its appearance gave me the same rush that I get when spotting a grizzly; that involuntary exhalation of awe that says, “beautiful!” Even the kids paused for a moment as it swooped, perched and drummed. While relatively common in some areas of Montana, over here, its sighting is a rare joy to be savored. The Pileated, a word which means “crested,” is our most magnificent woodpecker.