Why woodpeckers don't get concussions, a really weird tongue and other surprising facts about these birds
Woodpeckers are resourceful and beautiful. But they’re a lot weirder than you might think
Small brains, ridiculous tongues and a passion for percussion.
There are 239 species of woodpeckers, ranging in size from the tiny downy to the impressive pileated. Woodpeckers inhabit every continent except Antarctica and Australia, and their signature rat-a-tat is a familiar sound in forests and urban areas alike.
But there's a lot you probably don't know about these ubiquitous birds.
Woodpeckers: The Hole Story, a documentary from The Nature of Things, drills into what makes these creatures so fascinating.
They've got the beat
While they're not singers, woodpeckers can produce a variety of calls to warn others of danger, send signals to a mate or see off a rival. But their preferred mode of communication involves tapping out a tune on a hollow tree or stump.
Each species has developed its own style of patterns, speeds and rhythms. This allows other members of their species — and keen-eared birders — to identify who is speaking. Drumming often happens at dawn, as a way to tell others they still occupy the territory, but woodpeckers may drum at any time of the day.
Like their songbird cousins who practice their melodies, woodpecker brains are wired in a manner that suggests they may "learn" their drumming patterns — as opposed to, say, the naturally occuring screech of a hawk. And they try out their drumline on different trees or logs to create just the right volume and speed. That way, they can ensure their "song" reaches ears farther away.
In fact, woodpeckers are very resourceful and will often use other objects like rain gutters, telephone poles, transformers or street light covers to get that sound that sets them apart.
It's often thought that the rat-a-tapping is the birds digging for food, but woodpeckers are surprisingly stealthy when digging for insects or making a nest hole.
Their bird brains may be the key
If a human tried head-butting a tree with the speed and power of a woodpecker, they'd quickly end up with a headache or worse. So why don't woodpeckers get concussions — or at least headaches — after bashing their beaks into wood up to 12,000 times a day?
A small brain might be key.
It's long been thought that the woodpecker's skull acts like a sports helmet to absorb shock. But a recent study, which analyzed high-speed videos of woodpeckers hammering into trees, refuted that hypothesis. It found the bird's beak, head and brain all stop simultaneously when it hits the target — exactly how a hammer works — but no evidence of shock absorption.
As a result, experts wonder if the bird's brain, which is about 700 times smaller than a human's, avoids injury simply because its size and weight can withstand the force. And it turns out a woodpecker would have to hit a tree twice as fast as they do to give themselves a concussion.
Their empty nests are prized by other forest dwellers
A woodpecker's beak is a multi-purpose tool that it relies on daily — tapping out its morse code messages, searching for food or digging out cavities for a nesting hole.
As it turns out, a lot of other species rely on it, too.
Many other forest critters benefit from the woodpecker's handy work — squirrels, owls, songbirds and even snakes or amphibians use abandoned woodpecker nest holes for refuge or to raise their young.
In North America, woodpeckers are responsible for 99 per cent of the tree cavities used by birds and mammals.
They have just the weirdest tongues
Woodpecker tongues are long. Like, weirdly long, measuring up to a third of their total body length.
You aren't likely to see the whole thing though.
The majority of a woodpecker's tongue is hidden within its head. The base is anchored to the hyoid bone, which is in its nostrils. (The human hyoid bone is located under our jaw, a totally sensible place for it.) From the nostril, the tongue splits in two, wraps around the back of the skull and joins together again at the base of the beak. When muscles contract the hyoid bone, the tongue sticks out.
Different feeding habits among various woodpecker species result in an arsenal of tongue adaptations. Some are extra long for reaching into anthills while others have special brush tips for collecting sap.
The tongue also helps the woodpecker avoid injury when chiseling at objects. The hyoid contracts and tenses at each bash of the beak, holding the skull and spine in place.
They've mastered the balancing act
We know woodpeckers use their heads but they also have mastered some crafty footwork to ensure they have leverage to hit their target properly.
Thankfully, their strong short legs and sharp claws help them cling tightly to the bark. Each foot has two toes pointing forward and two pointing backward, offering an even better grip on a variety of surfaces.
But they also use their especially stiff tail feathers to brace themselves against the tree and get enough force when hammering. Though the feathers are stiff, their tips are flexible and can spread into crevices or cracks of tree bark, providing strong support on rough or smooth trunks.
Using this tripod-like support of legs and tail, the birds remain stable as they chisel their beaks into the wood.
They're on the move
A warming world and climate instability is spelling disaster for many animals, but woodpeckers seem adequately equipped to tackle climate change head-on, with evidence that some species are moving north.
The red-bellied woodpecker has been doing so for 70 years.
These plucky little birds with a flash of red on their chest and heads were once known as residents of the American southeast, rarely seen anywhere in the northeast of the U.S. About 40 years ago, they were found nesting near the Canadian border and today have settled in Quebec and Ontario.
Woodpeckers aren't alone in the bird world in their conquering of new lands. But their ability to adapt and create their own refuge in trees may help them survive as they continue their expansion north.