Getting to Know Washington's High-climbers
by Howard Youth
Hammer blows echoed through the woods, followed by slow, deliberate cries: "Guk...guk....guk...guk...guk...guk." In the forest darkness, my 14-year-old heart raced. I clutched my battered binoculars and wove between sweetgum, oak, and maple saplings, tiptoeing toward the ever-louder chuckling and hammering. As I drew closer, I heard wood shards rattle as they hit the leaf litter.
A few minutes later, I peered around a large white oak and found the perpetrator. About 30 feet away, a crow-sized bird clutched a dead oak, throwing its flame-red crested head against the tree's trunk. Candy-bar-sized bark chips scattered in all directions. Spotting me, the bird slowly flapped off on broad, white-splashed wings. It was a primordial sight. I had finally spotted Dryocopus pileatus, or "crested wood cleaver," commonly known as the pileated woodpecker.
That was 20 years and thousands of woodpecker sightings ago, but the flap and flash of a flying pileated woodpecker still thrills me. I have seen this bird in less pristine settings a few times in my backyard, and many times on the Zoo's huge tulip poplars and oaks. And I have often reflected on how fortunate it is for these birds and for those who enjoy watching them that they have been able to adapt to our ever-more-crowded world.
In fact, pileated woodpeckers are more common today than a century ago. In his 1898 field guide, Apgar's Birds of the United States, Austin C. Apgar wrote, "This bird was formerly distributed generally over the wooded regions of North America, but is now becoming very rare except in the wilder sections." Maturing second-growth forests and well-wooded suburbs have helped the pileated woodpecker rebound, especially in the East.
The pileated is the kingpin in a clan of seven woodpecker species that haunts Washington area woods. Most are common, and many overlap in certain wooded habitats. For both casual and avid bird watchers, woodpeckers are a delight. Their color, unique habits, quirky vocalizations, and cocky postures make them among the most interesting and distinctive of birds: the kind that draw people to study nature more closely.
Isn't Seven a Crowd?
How can six or seven woodpecker species share the same area without competing with each other? A short answer is that woodpeckers, like the various antelope species mingling on Africa's Serengeti, coexist by exploiting the bounty of forest and field in slightly different ways.
In the case of woodpeckers, their drilling equipment often influences feeding behavior. For example, the continent's smallest species, the downy woodpecker (Picoides pubescens), has an almost nail-like bill. This bird, our area's most common woodpecker, seeks insects lurking at or just beneath the bark of trees of all sizes. The versatile downy also leaves the trees to tap at wasp galls and other food items on tall weeds. I have seen downy woodpeckers working over young ornamental trees on Dupont Circle, oblivious to the legions of pedestrians and surrounding traffic.
The hairy woodpecker (Picoides villosus) bears almost identical markings to the black and white downy, but sports a longer, heavier bill, and is larger. More specialized than the downy, the hairy digs for wood-boring insects in the large dead or dying trees of mature woodlands.
The deepest excavator by far, the crow-sized pileated woodpecker pounds its formidable chisel deep into soft, dead wood, where this bird finds its favored prey, carpenter ants, as well as termites and the larvae of wood-boring beetles. Its telltale excavations, five-inch-long rectangles, brand many dead or dying trees.
Perhaps North America's most avid winged ant-eater, the northern flicker (Colaptes auratus) takes a different approach toward finding prey. This dove-sized bird, with a somber brown, black-barred back and striking breast and face markings, sticks to the ground. Flickers do nest, rest, court, and forage in trees, but in warmer months they spend much of their time on the forest floor, lapping up ants at anthills or on fallen logs.
The yellow-bellied sapsucker (Sphyrapicus varius), whose bizarre name often induces chuckles among non-birders, is a winter visitor here, spending its days creeping along tree trunks and tapping neat horizontal rows of small holes. From these holes seeps sticky sap, the sapsucker's favored winter food. On warm days, the sap also attracts insects, including large numbers of ants, an additional food source for the birds. At least 35 other bird species feed at sapsucker seeps, including other woodpeckers and a variety of warblers.
Many woodpeckers also eat fruits, nuts, and even bark. The red-headed woodpecker (Melanerpes erythrocephalus) is probably the most omnivorous woodpecker in our region. Vegetable matter, including cherries and other fruits, seeds, beech nuts, acorns, and bark, makes up as much as two-thirds of its diet. Red-headeds also devour insects and arachnids on occasion, as well as the eggs and nestlings of other birds.
The much more common red-bellied woodpecker (Melanerpes carolinus) also eats a variety of plant and animal foods. Named for a few rarely visible reddish belly feathers, this red-crowned, stripe-backed bird has pushed north in recent decades, probably aided by the rising popularity of bird feeders. In backyards, red-bellied woodpeckers often dine on offerings of suet and sunflower seed.
The Essence of a Woodpecker
Woodpeckers belong to a separate scientific order (Piciformes) than the sparrows, robins, orioles, swallows, flycatchers, starlings, finches, and other songbirds of the order Passeriformes. Woodpeckers lack the syrinx, or voice box, that characterizes songbirds. Although they do vocalize, woodpecker calls lack the rich diversity of sound for which songbirds such as mockingbirds, nightingales, canaries, and orioles are famous.
The order Piciformes includes woodpeckers, toucans, and barbets, with the family Picidae reserved for woodpeckers and Eurasia's two species of odd-looking wrynecks. The world’s 212 woodpecker species are found from Patagonian plains to African savanna to North American and Eurasian boreal forests up to the treeline: all continents except Australia and Antarctica. North America hosts 22 species, including the seven that reside in or near Washington.
Woodpeckers’ physical adaptations for their odd style of feeding include strong head and neck muscles, heavily ossified skulls with tissue padding between the eyes, short legs, and extra-stiff tail feathers that prop them at their characteristic 45-degree angle from pecking surfaces. Unlike songbird feet, which have three toes in front and one behind, the feet of most woodpeckers have two-toes fore and two aft, a configuration that offers better traction and balance on vertical surfaces.
Aside from their bills, woodpeckers' most valuable tools are their tongues. Once prey crawls into view or is exposed by excavation, the birds’ long, flexible, bristle-tipped tongues go to work. In many species, the tongue can extend the length of the head. Tipped with sticky saliva, this quick-moving, flexible organ mops up the meal and hauls it back to the bill.
Breeding Basics
When spring approaches our region, many woodpecker pairs begin to defend nesting territories, while unpaired males advertise for mates: calling, drumming, or exhibiting head-bobbing or wing-spreading displays. Spring breeding season can be the toughest time of year to find woodpeckers, according to Mark Garland, senior naturalist at the Chevy Chase-based Audubon Naturalist Society (ANS). "They make all sorts of noises up until eggs are laid, then they quiet right down," says Garland. Once paired, woodpeckers are basically monogamous, except for the occasional extra-pair mating.
Woodpeckers nest in tree holes, and lay all-white eggs which rest from ten inches to two feet down dark tree cavities. Woodpecker parents do not stuff or line their nests with special materials as many other birds do. Instead, their eggs sit on bark or wood chips that have fallen into the cavity during excavation. Pairs share parenting responsibilities. During the day, the male and female switch off on incubation duties. Once the eggs hatch, usually between 11 and 18 days depending upon the species, they share in feeding their young.
From hatching to fledging, nestling woodpeckers usually stay in their nest cavities three to four weeks. In our area, most species nest only once a breeding season, with the exception of northern flickers and red-headed woodpeckers, which often attempt a second nesting.
In Search of Woodpeckers
If you want to get better acquainted with local woodpeckers, your backyard is a good place to start. Northern flickers and red-bellied and downy woodpeckers nest in local parks and neighborhoods throughout the area. Although less active, the migratory sapsucker quietly taps away at a variety of suburban trees during the winter. Offerings of suet, chopped peanuts, and sunflowers frequently draw downys and red-bellieds, but individuals from all seven species visit feeders at least occasionally.
Late fall and winter are ideal woodpecker-searching times: Sapsuckers are present, leaves are off the trees, and the birds are active. But woodpeckers' tapping, pecking, and strident calls can be heard most of the year. With a little practice, it's easy to stroll through the woods and pick out the rolling "clurr" or "kiv-kiv" of the red-bellied woodpecker, the descending whinny of the downy woodpecker, the formidable "guk-guk-guk-guk-guk" of the pileated, and the faster, less-erratic pre-nesting call of the flicker: "kek-kek-kek-kek-kek-kek."
However, some woodpecker sounds take a bit of careful consideration. The hard-to-find red-headed woodpecker’s "queerhk" sounds similar to the red-bellied's call, but harsher. Trained ears can easily decipher the hairy woodpecker's strong "peek!" from the downy woodpecker's brief "pihk," or the sapsucker's weak "meehw."
The greater Washington area is much better suited for woodpeckers than it was in the 1940s and 1950s. The protection of mature forests certainly has helped nurture the birds. Woodpecker hotspots include Fairfax's Huntley Meadows Park, Montgomery County's Wheaton Regional Park, Rock Creek Park, and the woodlands on both sides of the Potomac at C&O Canal National Historical Park.
The canal is truly a woodpecker haven. There, extraordinary numbers of woodpeckers live along a 185-mile-long band of mature woodlands that grew up after the canal shut down in 1924. These productive forests grow on rich soils nourished by the Potomac's seasonal ebbs and flows. Along some stretches, beaver dams flood the woods, providing an abundance of dead trees for nesting.
Some of the best-surveyed woodpecker spots lie on the stretch of canal running through Montgomery County, such as the area near where Seneca Creek runs under the canal at Riley's Lock and into the Potomac. The 1999 National Audubon Society-sponsored Christmas Bird Count at Seneca produced some of the continent's highest counts of northern flicker (426), pileated woodpecker (120), and yellow-bellied sapsucker (101). In previous years, the area yielded top numbers of downy woodpeckers too. While the canal hosts many woodpeckers, Garland thinks that more remote areas likely support even more. "At the canal, I think it's a combination of really excellent habitat along the Potomac and a lot of people out counting," he says.
The Troubled Trio
However, even a thorough search of the C&O Canal rarely reveals a red-headed woodpecker these days. A century ago, the red-headed was considered our area's most common woodpecker. These black-backed, scarlet-headed birds once thrived in rural backyards, orchards, and tree-studded pastures. "With the exception of the mocking-bird, I know of no species so gay and frolicksome," wrote John James Audubon of this gaudy creature. Today, the red-headed is scarce, gone from the northeast part of its expansive eastern range and from many haunts around the Beltway.
The red-headed woodpecker often forages on the ground, but is no more street smart than an opossum. On a 200-mile Iowa road trip in 1924, a man named Dayton Stoner counted 105 roadkills, of which 39 were red-headed woodpeckers. Stoner listed the bird's habit of foraging on roads, hesitance to flee oncoming vehicles, and lazy flight as contributions to its decline.
Others speculate that the introduced--and aggressive--European starling has played a part in the red-headed woodpecker's decline. I remember watching a lone red-headed woodpecker, which frequented the Seneca area, tangle with a gang of three starlings. The starlings constantly harried the woodpecker. At one point, the birds, locked in combat, tumbled from the woodpecker's favorite dead tree to the ground. Introduced to New York City's Central Park in 1890 and now found continent-wide, starlings often nest in tree cavities, but never excavate their own. Instead, they often usurp holes being used by woodpeckers or other cavity nesters such as bluebirds.
However, biologist Danny J. Ingold has challenged the assumption that starlings are the primary villains. During a study conducted over three breeding seasons in east-central Ohio, Ingold found that it was the red-bellied woodpecker--not the red-headed woodpecker--that suffered most from conflicts with starlings. Red-bellied woodpeckers and starlings were both nesting in early April, while red-headed woodpeckers began nest excavations in early May--after starlings had settled on their nests.
Ingold also found that red-headed woodpeckers and flickers defended their nest holes more aggressively from interloping starlings than red-bellieds did. In the end, red-bellied woodpeckers lost 39 percent of their cavities to starlings, while red-headed woodpeckers only lost 15 percent, and flickers 14 percent.
Landscape changes likely represent the greatest problem to red-headed woodpeckers. According to Robert A. Askins, professor of zoology at Connecticut College and author of Restoring North America's Birds, "The red-headed woodpecker is a bird associated with open, agricultural habitats with scattered trees, so the main reason for its decline in the Northeast is reversion of farmland to forest. Almost all of the species typical of open fields have declined in the Northeast for this reason."
Locally, much of the red-headed woodpecker's rural habitat has been replaced by maturing woodlands, housing developments, office parks, and malls. Today, these woodpeckers are most frequently found in large areas of recently killed trees, such as those created when beavers flood forests with their dams.
If they continue to decline, red-headeds would not be the first woodpecker species to disappear from our area. In Audubon's day in the early to mid-1800s, ivory-billed woodpeckers (Campephilus principalis) thrived in the swamp forests of the Deep South, and were even spotted in Maryland on occasion. This largest of North American woodpeckers required large expanses of well-timbered wilderness—a rare commodity in the Southeast today. The ivory-billed is now presumed extinct.
The red-cockaded woodpecker (Picoides borealis), an endangered southern species, until recently nested on Maryland's Eastern Shore, around Blackwater National Wildlife Refuge. The last confirmed nesting at the refuge took place in 1958; the last sighting in the mid-1970s. Red-cockaded woodpeckers nest in open, parklike stands of old growth pines; they are the only species of North American woodpecker to excavate nesting holes exclusively in living wood. Frequent tree harvests and fire suppression severely limit the birds' specialized habitat. Today, the closest known red-cockadeds nest on private lands in southern Virginia, where their status is tenuous at best.
Closer
to the Beltway, however, most woodpeckers--with the exception
of the red-headed--remain common despite the presence of starlings,
and increasing development. From the tiny downy woodpecker
to the mighty pileated, woodpeckers remind us that our well-wooded
region is more than the nation's capital--it's a capital place
for woodpeckers as well.
More than Just Dead Wood
Occasionally woodpeckers give the trees a break, and hammer instead on human property. In June 1995, the Discovery space shuttle had to be rolled back from its launch pad at Florida's Kennedy Space Center after flickers pecked 195 holes in the foam insulation of its external fuel tank. During the repairs, round-the-clock woodpecker watchers were stationed at the launch pads, and noise makers blared. The Discovery took off a week later.
Back in Washington, suburban woodpecker damage is relatively rare, which is surprising considering the abundance of woodpeckers in our area. Woodpeckers usually keep to the trees, sounding off on hollow dead limbs and digging into rotting wood for nest cavities or food. However, in early spring, downy woodpeckers and flickers will advertise their territory by pecking on rain gutters--an activity that causes more noise than damage, and stops once the birds start nesting. Woodpeckers seeking food or nesting cavities sometimes will turn their attention to houses, especially those with wood siding. Carefully placed netting, although unsightly, can effectively bar persistent woodpeckers from targeting homes.
Fortunately, no real woodpeckers can match the destructive potential of animator Walter Lantz's impish cartoon character, "Woody Woodpecker," which debuted in 1940. Raucous and quite large, Woody was likely inspired by the pileated woodpecker, although his coloration more closely resembles that of the red-headed woodpecker. He certainly caused far more of a nuisance than either species.
-Howard Youth
ZooGoer 29(3) 2000. Copyright 2000 Friends of the National Zoo. All rights reserved.
