Sunlight streamed through the tree trunks as we meandered into the warming woods. The Ruffed Grouse’s thumping faded into the distance as we left his territory. In its place a loud, staccato drumming echoed through the hills, followed by the wildly laughing cry of a Pileated Woodpecker. My ornithology professor nicknamed pileateds the “monkeys of the Northwoods” due to their raucous, whinnying calls.
Like grouse, Pileated Woodpeckers are not daunted by our northern winters, and maintain their mates and territories throughout the year. Activity has ramped up recently, though, with the onset of spring and breeding season. Unlike the melodious warblers who are singing their way north right now, woodpeckers use drumming to attract a mate and defend a territory. “With such energy did he hammer that his whole body shook and his wings quivered. He fairly hurled himself wildly at it,” described the naturalist Ernest Waters Vickers in 1915. They add to the pulse of the forest.
Woodpeckers beat on trees for three main reasons: to forage for food, to excavate a nest cavity, and to drum for communication. The first two are relatively quiet affairs, done slowly and deliberately. The third is as loud as possible. Woodpeckers prefer the resonant acoustics of a hollow trunk or branch on which to drum—or a stove pipe or rain gutter—to make sure that their message gets across loud and clear. Both male and females drum.
I’m not sure who was drumming the beat we heard, but as we peered through the tree trunks, one large bird swooped through the maze and landed low on a bole, followed shortly by its mate. Then again, one swooped off and the other one followed. Were they just searching for food together? Or performing their mating dance? In 1908, Francis H. Allen witnessed their ritual,
“They hopped up and down the trunk, frequently pecking at each other's bills simultaneously, now on one side of the tree, now on the other…They hopped backward and downward a great deal, and often they lifted and partly spread their wings. Their motions were limber and undulating, marked by a certain awkward grace.”
After the thrill of their mating rituals come the more domestic duties. Pileated Woodpeckers use their large, straight, chisel-like bill to excavate a new nest hole each year. The male seems to do most of the excavation of oblong hole, removing wood chips from the area as they go. Dense, mature forests tend to contain the large, dead trees that they prefer. In young forests, when old, dead nest trees are the tallest ones around, lightning can present a hazard to nesting birds.
Although there is a significant time investment – each cavity takes 3-6 weeks to complete – woodpeckers will not reuse the hole in subsequent years. This probably serves to protect the babies from parasites, or from mammalian predators who might remember the location from year to year.
In the years after the woodpeckers raise their brood of 3-5 young, a wide variety of birds and mammals will use the abandoned cavities. Other woodpeckers, wood ducks, bluebirds, flycatchers, owls, bats, squirrels, and pine martens all benefit from pre-drilled cavities. This makes Pileated Woodpeckers a keystone species for their crucial role in creating habitat.
The pileated pair leap-frogged their way deeper into the forest, and we continued hiking. Several times we noticed piles of fresh wood chips near the trail, and looked up to find a tree trunk perforated by large, rectangular holes from the woodpeckers’ foraging activities. Nest trees have no such tell-tale signs, since the birds carry away all chips, nest debris, and feces that might give away the location of eggs and babies to a nest predator.
These days, it seems our Pileated Woodpeckers are having good luck with reproduction. Hardly a day goes by when I don’t hear the “monkey of the Northwoods,” or catch a glimpse of this striking black-and-white bird in its undulating flight. It wasn’t always that way. Pileateds were considered rare in 1900s, due to habitat loss and hunting. When the forests rebounded, so did the birds. I like the sound of that.
For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! We are currently constructing our new exhibit: “Lake Alive!” which will open May 1, 2015.
Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com.
|Photo by Larry Stone|