Vol. 13 Issue 3, Fall 2008
By Nicole Hamilton
Woodpeckers are unique birds that have been around for approximately 50 million years. Their drumming, which to many Native Americans symbolized the heartbeat of the earth, can be heard in woods around the world as they are found on every continent except Australia and Antarctica.
Woodpeckers are unrivaled when it comes to finding and catching insects tucked under bark, hidden within wood, or burrowed under ground in tunnels. Their bills are adapted for hacking and chiseling. Their feet have two toes forward and two backward to help with grasping vertical surfaces of tree trunks, and their fourth toe can even go sideways. Their tails have stiff shafts that help prop them against the trees. Their skulls have extra cushioning to protect their brains from the constant impact of the drumming and drilling. Their tongues, which coil up into their skulls, are long and barbed to help snag insects hiding in crevices. Unique birds indeed.
Communication among woodpeckers is also special, as it is done through body movements, special calls, and drumming. With the ruffling of their crest feathers on the top of their heads they may warn another bird to stay away. With their head bobbing left and right they define territories and engage in courtship displays. With the raising of their wings in a v-shape as they perch on a tree trunk, they signal to competitors to stay away or be attacked. As with other birds, they have their contact calls and territory calls, and their loud voices often resound throughout the woods, but their drumming is unique to woodpeckers. The drumming, which is done on resonating surfaces, is used to define territories and attract mates and is done by males and females alike. They seek the best resonating surface on hollow trees in their territory — or sometimes the best resonance is found on gutters, garbage cans, or house siding! It should be noted that drumming is different from cavity excavation and foraging. When a woodpecker is drumming, no wood is excavated. Rather, it’s the sound that matters and actual chiseling is left for other times.
This takes us to their other unique trait, and that is their ability to excavate cavities in trees for nesting and roosting. Cavities are often used for years, in some cases by the pair that made them, but also by numerous other species of animals. Birds such as bluebirds, nuthatches, Tufted Titmice, Tree Swallows, House Wrens, chickadees, owls, Wood Ducks, kestrels, and others will use woodpecker cavities for nesting. Flying Squirrels and Gray Squirrels use them for nesting as well.
Woodpeckers play a key role in our ecosystem as they help keep wood-boring insects in check, keeping trees healthy. Dead bark is loosened and dropped to the forest floor, making it more accessible for decomposition organisms to go to work and turn the bark into soil. Where woodpeckers have pecked and loosened bark, other birds like the brown creeper and chickadee follow to forage for remaining insects and spiders. Because owls will use woodpecker cavities, they indirectly help keep the rodent population of a woodlot in check as well. The biggest threats to our woodpeckers are habitat loss through forests that are cleared or harvested for mature trees and habitat removal by landowners who clean out dead standing trees from wood lots. Both of these activities deprive the birds of nesting sites and food. We need to let dead trees stand if we want to let the woodpeckers live.
There are over 200 species of woodpeckers worldwide. Here in Loudoun, we are graced by the sights and sounds of seven species: Downy, Hairy, Red-bellied, Red-headed, Pileated, Northern Flicker, and the Yellow-bellied Sapsucker. All of these except the Yellow-bellied Sapsucker are year-round residents. In addition to these residents, there was one accidental visit by a Lewis’s Woodpecker that was recorded in Lucketts in 1989 — a very unusual occurrence since this woodpecker is typically found much further west. Below and in the next issue, we will take a look at these fascinating birds living in our forests and backyards, for while they have their similarities, they also have their special adaptations.
Downy Woodpecker: The Downy Woodpecker is our smallest and one of our most common woodpeckers and will readily come to feeders. It is often confused with the larger Hairy Woodpecker, whose longer, thicker bill distinguishes it from the Downy’s short, sharp bill. For the sharp observer, you can determine how many individual Downies you have by studying the pattern on the backs of their head, since the pattern is unique like a fingerprint. Downy Woodpeckers are present here year-round, but they do make some seasonal shifts north and south so you may have different individuals in your yard at different times of the year. The territory of a Downy Woodpecker is about ¼ acre. If multiple pairs are in an area, their territories may overlap to some degree. Males typically forage at the top of the canopy while females do so at the mid-canopy. Through fall and winter, males and females will stay away from each other, with males even chasing females away. In late winter, however, males will start drumming as they declare their territories and advertise for a female. As mates are selected, the male and female Downy will gradually start to synchronize their activities and together will select a tree for excavation. If they do not agree on the tree, breeding may not occur that year, but if they do, the excavation and raising of young becomes their entire focus for the coming months. Nests are made 5 to 40 feet high, often toward the top of a broken stub of a tree. With the nest complete, Downy Woodpeckers will spend 40% of their time at or near the nest. During incubation of the eggs, both parents participate and they do so in 30- to 60-minute shifts. When one flies up to the entrance to relieve the other, it lands on the side of the tree and taps to the mate inside, which gets the signal and flies out, allowing the other to enter. The male stays in the nest throughout the night. Once the young fledge, the parents will feed them for several weeks before they disperse. Throughout winter, Downy Woodpeckers mingle in mixed flocks with chickadees, nuthatches, and titmice. They are generally found in woodland edges and residential areas. In fall and winter, the Downy Woodpecker is the primary predator of the fruitfly larvae, which is especially found in goldenrod galls. They also feed on scale insects on birch trees and other insects hidden in bark. Poison ivy berries are a favorite food.
Hairy Woodpecker: The Hairy Woodpecker looks similar to the Downy but is larger. It too has a territory of about ¼ acre that it defends for nesting, but it has a range for foraging of about 6–8 acres and prefers mature woods with extensive forest areas around. To defend its territory, the Hairy Woodpecker drums on “signal posts” located across its range which can include gutters and drain pipes but most often are resonant trees. The male and female of a pair will have two to four signal posts each that they use for drumming. Hairy Woodpeckers nest in living trees and put their cavities 10–40 feet off the ground. They especially like oak trees with a diameter of at least 8 inches but will use other trees of similar girth. Courtship and selection of a mate begins in January and lasts through April. Once a pair has bonded for the year, they will give a soft “tew-tew” call to each other to keep in contact through their range. As with other woodpeckers, they typically have just one brood per year. Both male and female incubate the eggs and they rarely leave the nest unattended. To alternate brooders, the incoming Hairy will perform a swoop flight up to the hole and may give a wing clap. This is followed by the “tew-tew” call at the entrance and head waving. The bird then hops to the side, allowing the bird inside to depart and they make the switch. The male broods throughout the night and the female relieves him at sunrise. After the young have fledged, the parents will only feed them for a few days, but they still stay within their parents’ range and ultimately may never go more than about a mile from their birthplace. Hairy Woodpeckers have longer tongues than Downies and therefore drill deeper in search of wood-boring insects and larvae. Watch the Hairy Woodpecker as it taps the tree to determine just where to drill. In addition to insects, the Hairy will also cache poison ivy berries in bark crevices and feed from the sap wells drilled by the Yellow-bellied Sapsucker.
Red-bellied Woodpecker: The Red-bellied Woodpecker is our most common and comes readily to feeders. At first glance, you may question its name as the belly appears devoid of red, and in fact the Latin name for the Red-bellied Woodpecker is Melanerpes carolinus, which means “black creeper of the Carolinas.” It has a black and white zebra-striped back and a broad swath of orange/red on its head, but with a careful eye, you can see the touch of rouge on the whitish midriff. One of the most interesting things about this woodpecker is its courtship display. The male begins with slow drumming and tapping along with loud “kwirr” calls. If the female is interested, she will join the male and begin tapping beside him. He then begins to chisel a cavity, and if she approves of the site, she keeps tapping beside him as he excavates in earnest. Both male and female will complete the excavation. When it comes time to incubate the eggs, both male and female pluck feathers from their lower bellies to create areas of bare skin called brood patches that they put over the eggs to warm them. Red-bellied Woodpeckers, while they feed on insects and spiders, are primarily vegetarians preferring nuts, seeds, corn, and fruits, even in summer when insects are plentiful. They are not big peckers of wood but prefer to glean from the surface and pick fruits and berries, especially enjoying the fruits of mulberry, Virginia creeper, and poison ivy, which they will cache along with nuts in tree crevices. Nests are excavated up high on a recently dead tree that still retains its bark or on a dead limb of a living tree. They often place their cavity on the underside of the limb, perhaps for protection from rain. When the babies fledge, they are still weak fliers and many fall prey to cats as well as Sharp-shinned and Coopers Hawks. The parents continue to care for them for about a month after fledging, helping to protect and feed them. Great Crested Flycatchers as well as kestrels use abandoned cavities as their nesting sites.
For Part 2, click here:
A Guide to Bird Behavior, Vol I, II and III, by Donald and Lillian Stokes, 1989.
Lives of North American Birds, by Kenn Kaufman, 1996.
America’s Favorite Backyard Birds, George and Kit Harrison, 1989.
Woodpeckers of North America, Frances Backhouse, 2005.