You'll Know it When Pileated Woodpeckers Come a Knockin'
The sounds of heavy hammering on our home’s barn-board siding vibrated into my basement office, making me think, “That’s no small woodpecker.”
Running upstairs, I flung open our patio’s sliding door, causing a pileated woodpecker to cease pounding and take wing, sending barn-board chips flying in its wake. Looking up, I spotted its work site, a narrow foot-long scar in a board that now required paint.
The pileated wasn’t the first woodpecker I’ve chased off our home. More often I catch a downy or hairy woodpecker vandalizing our place, but pileateds sound more like jackhammers than tack-hammers. Then again, I haven’t caught a sapsucker, Northern flicker or red-bellied woodpecker abusing our siding, so maybe I shouldn’t assume pileateds are the loudest, most destructive workers.
But if size matters, my assumption seems safe. According to National Geographic, some adult pileateds measure 16.5 inches beak to tail-tip. That’s only 3 inches shorter than the presumably extinct ivory-billed woodpecker, but about 7 inches longer than a red-bellied woodpecker.
In other words, pileateds are big birds that can stand beak to beak with most crows. And although they aren’t as common as crows, pileateds have never been more populous in modern times.
That’s because Wisconsin’s forests and woodlands have regrown the past century after our logging era, generating more of the old, large trees pileated woodpeckers require for nesting and roosting cavities. Wisconsin researchers report that pileateds excavate cavities with inside diameters of 6 to 8 inches, usually in trees with minimum trunk diameters of 12 inches.
Jim Woodford, who works in the Department of Natural Resources’ Rhinelander office, said recent censuses – the annual Christmas bird count and Wisconsin breeding bird survey -- found pileateds have increased by multiples of 5 to 9 since the late 1960s and early 1970s. Further, pileated populations are up nationwide.
Perhaps not surprisingly, deer hunters are among those reporting more pileated sightings in recent years. Typically, people hunting Wisconsin’s mature forests and woodlots see fewer white-tailed deer but more pileated woodpeckers because aging woodland habitats favor these year-round feathered residents. As trees age and rot from disease or insect infestations, pileated woodpeckers mine them for grubs and insect larvae, and open up large cavities for roosting and nesting.
Pileateds are also easily identified because of their large size, red-capped heads and laughter-like calls, which inspired the cartoon character Woody Woodpecker. Plus, pileateds don’t require secluded settings. They’re often seen in towns, villages and small rural cities across much of Wisconsin, primarily north and west of a line from southern Kewaunee County to our border near Dubuque, Iowa.
Ryan Brady, a researcher in the DNR’s Ashland office, said he often hears from homeowners who want to know how they can prevent pileateds and other woodpeckers from damaging their homes. The birds do their worst work on log homes, sometimes excavating nesting cavities into individual logs. In homes with standard wood siding, pileateds seldom hammer out cavities. They primarily look for food and move on after chiseling out an exploratory hole or shallow trench.
Although pileateds will hammer wood repeatedly in spring to stake out territory and advertise their breeding availability, that behavior is more common with flickers and sapsuckers. Breeding woodpeckers even hammer on metal surfaces and aluminum siding to loudly broadcast their intentions.
Is there an effective way to stop woodpecker attacks on our homes? “If you know a reliable way, you’ll be a rich man,” Brady said. “I’ve seen long lists of things you can try – such as chemicals, wind chimes or blocking off the holes – but no one has found a magical cure. Most people just want to kill them, but that’s not a good option.”
Doesn’t all that jackhammering blunt the woodpeckers’ bills? No. Their beak is more like a fingernail than a tooth. It might deform a bit to lessen the impact on the bird’s skull, but beak material continually regenerates.
Further, woodpeckers don’t suffer concussions from the hammering, which researchers estimate is a force 1,000 times that of gravity. In contrast, Air Force tests in the 1950s estimated that humans die at g-forces 46 times that of gravity.
Woodpeckers, however, have thick neck muscles to diffuse the blows, and a third inner eyelid to help keep their eyeballs in place. Recent research in China also examined the skull bone that cushions the woodpecker’s brain. This thick, spongy bone apparently is made of beam-like projections that form a mineral mesh to act as brain armor.
The researchers are hoping to better understand the microstructure of woodpecker skulls so they can develop better headgear for high-impact sports and dangerous work.
Of course, woodpeckers often use their beaks to probe for food in mediums far softer than wood. In April 2014, for instance, I watched a female pileated woodpecker and a Northern flicker working alongside robins as they hunted worms in my backyard. Meanwhile, about 20 yards away, a male pileated woodpecker hammered at a punky scar in a silver maple. That particular wound opened in June 2001 when a windstorm ripped a large branch from the tree, peeling bark all the way to the ground.
I left the tree standing, curious to see if it could repair itself. The wound grows less obvious every year, but the pileated woodpeckers aren’t fooled. They keep inspecting and prospecting, apparently finding enough protein to justify their efforts.
And that’s fine with me. Better the maple suffers their endless probing than my home’s siding.