Woodpeckers

Joe Meche is in his sixth year as editor of the Avalanche, the newsletter of the North Cascades Audubon Society, and a member of the board of directors.

The amazing variety of birds in the world today is the culmination of millions of years of evolution and adaptation. Through the phenomenon known as adaptive radiation, bird characteristics and behavior evolved as a reflection of the basic requirements of different ecosystems; e.g., bill length and shape adapted to the type of food eaten; leg length and foot type changed in relation to perching or locomotion; wing shapes changed in relation to flight patterns; etc.

Woodpeckers belong to the family Picidae and are classic examples of adaptive radiation. They use their sharp, powerful bills to chisel out cavities for their nests, to seek food, and even to drum out signals to define their territories. With the lone exception of the three-toed woodpecker, woodpeckers are zygodactyl, having two toes pointing forward and two pointing backward, enabling them to cling to and walk up and down tree trunks. Stiff tail feathers create a tripod-like support as they perform their amazing feats while searching for food and building their nesting cavities.

Woodpeckers have unusually long tongues which are barbed at the tip for spearing wood-boring insects and, when coated with saliva, enable them to catch ants. The woodpecker tongue is actually set into two cartilaginous hyoid bones which begin at the base of the bill’s interior and proceed to the back of the head; they then curve down beneath the skull cap, over the cranium, down through an eye socket, and forward until they’re just above the point where they started: the base of the tongue.

Because of this incredible adaptation, most woodpeckers can stick their tongues out more than twice the length of their bills. Sapsuckers drill evenly-spaced rows of holes in tree trunks both for the sap and for the insects it attracts. The skulls of woodpeckers are strengthened and the brain is cradled and cushioned to withstand repeated shocks of hammering into tree trunks. Through the remarkable process of evolutionary physiology, woodpeckers are able to beat their heads against hard objects all day long and keep coming back for more.

When I was growing up in southwest Louisiana, the most prominent woodpeckers were the red-bellied, red-headed, and pileated. When I became interested in birds, I wasn’t that far removed from the last known sightings of the ivory-billed, so I was always on the alert on canoe (read, pirogue) trips into the back bayous near my home.

The pileated woodpecker is only slightly smaller than the ivory-billed and is quite remarkable in its own right. The first thing that gets your attention is its size, not to mention the flashy red crest or the loud call that shatters an otherwise quiet morning outing! You can tell when a pileated has been working on a tree by the elongated holes in the trunk, as opposed to the more symmetrical and smaller holes made by other woodpeckers. Pileated woodpeckers are nothing short of spectacular and a joy to watch when the wood chips are flying. Walter Lantz was impressed enough that he used the pileated as his inspiration for everyone’s favorite cartoon woodpecker, Woody.

The other members of the woodpecker family are smaller than the pileated, ranging in descending order from the northern flicker to the downy. Wherever woodpeckers live, they are the carpenters of the avian world. They drill nest holes in tree trunks, or in large cacti in the case of some southwestern species. When abandoned, these holes provide nesting holes for numerous other cavity nesters, including small owls.

While all species share certain woodpecker-like characteristics, there is quite a bit of specialization within the family. The acorn woodpecker of the West is sociable and can be found in small colonies. The distinctive trait of the acorn woodpecker is that it drills holes in tree trunks to store acorns for its winter food supply. Members of the colony work together to fill the granary tree and share the food supply throughout the winter. The same trees can be used year after year.

The Lewis’ woodpecker eats fruit, acorns, and other nuts and has also been known to store acorns, but mostly in existing crevices in trees. The Lewis’ also flies out from perches to snare insects on the wing. In contrast to other woodpeckers, the Lewis’ is generally silent. This woodpecker was named after Meriwether Lewis of the Lewis and Clark Expedition, who collected the first specimen near Helena, Montana, in 1805. That particular specimen is still on display at the Harvard Museum of Comparative Zoology and is the only specimen that still exists from the expedition.

The red-cockaded woodpecker of the southeastern states drills small holes around its nest opening so that pine pitch oozes down the trunk to serve as predator protection. Certain species of snakes are known to climb trees to raid birds’ nests and dine on the contents. The pitch also serves as a distinctive signpost—sort of an avian house number.

The most common woodpecker species in Whatcom County are the red-shafted form of the northern flicker, the downy, hairy, and pileated woodpeckers, and the red-breasted sapsucker. These five species are usually present during the Bellingham Christmas Bird Count. A hike into the North Cascades and just over the crest to the east side could be enlivened by sightings of red-naped or Williamson’s sapsuckers, and black-backed or three-toed woodpeckers.

If you happen into the Ponderosa forest on the east side of the mountains, you might encounter the beautiful white-headed woodpecker, a regular sighting in the area around Sullivan Pond, northeast of Winthrop in the Methow Wildlife Area.

I observed a Lewis’ woodpecker at the nursery on the Old Fairhaven Parkway last year as it dined on apples in a tree next to the office. There have also been local sightings of flickers that are intergrades between the locally-common red-shafted and the yellow-shafted from east of the Rockies.

Woodpeckers are classified as migratory, non-game birds and are protected by the Migratory Bird Treaty Act. The most significant threat to woodpeckers is loss of habitat, as was the case with the ivory-billed, which is presumed extinct.

According to data from the Breeding Bird Survey, red-headed and Lewis’ woodpeckers and northern flickers are declining, while hairy, red-bellied, and pileated are increasing. Red-cockaded woodpeckers are on the Endangered Species list and are afforded full protection. Several woodpecker species are on the Watch List, a cooperative program of the National Audubon Society and Partners in Flight. The Watch List identifies species that are at risk and likely to become endangered if protection is not implemented.

To further enhance your enjoyment of watching birds, get to know the members of the woodpecker family. Woodpeckers are amazing birds to observe and can be quite tolerant of humans. Whether they’re chiseling away at a new nesting hole or searching for food, they can be quite animated and even amusing at times. Next time you’re out and about in wooded areas, listen for the tell-tale drumming, and locate the drummer. You’re sure to be entertained.