Monthly Archives: Sep 2018

Meet the Woodpecker That Impersonates a Snake

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( National Geographics; 19 september 2018)

The Eurasian wryneck can’t put a spell on you, as people once believed, but it does have a few tricks up its sleeve.

This bird’s motto is fake it till you make it. Or in this case, fake it until the threat of being eaten has passed.

That’s the strategy of Eurasian wrynecks, small brown woodpeckers native to Europe, Africa, and Asia. When spooked, they bend and twist their head from side to side, often while hissing, to imitate a forest snake.

“Whenever you catch a wryneck, they usually wiggle with their neck to imitate some kind of snake,” says Anders Nielsen, a student at the University of Copenhagen, who shot the video at Denmark’s Gedser observatory, where scientists capture wrynecks each summer and apply leg bands to monitor their population.

“Moving its head and throat from side to side … it looks pretty strange.”

Once considered otherworldly and a sign of magical powers, the odd behavior is now known to be a form of self-defense, he says. And it’s something of a genius strategy: If you’re not scary yourself—perhaps, you don’t have sharp talons, quick speed, or a powerful bite—impersonate an animal that’s more terrifying. Why not a snake? (See how snakes, spiders, and other animals fool their prey.)

In the hand of a bird bander, the display might not be so convincing. But shrouded in the shadows of a dark tree cavity, where these birds nest, the disguise is sure to trick stoats, goshawks, and other feather-hungry predators, says Kenn Kaufman, a renowned bird expert and field editor at Audubon magazine.

“If you’re a wryneck sitting inside a cavity, writhing around and looking and sounding like a snake is likely to make just about any predator retreat,” he says. “The more snakelike it looks and sounds, the more effective the defense could be.”

One Weird Woodpecker

Wrynecks are in the woodpecker family, but they don’t exactly fit in—at least at first glance.

For one, they don’t peck wood. Instead, they nest in holes that other species have laboriously excavated for themselves. And unlike their tree-drilling brethren, wrynecks forage on the ground, using exceedingly long tongues to slurp up fat-rich ants. (Related: How woodpeckers can thrive in leafy suburbs.)

 

But while they don’t look or act like your typical backyard woodpecker, wrynecks share important features with them, including a long, flexible neck packed with muscles. (Related: Why woodpeckers don’t get headaches.)

It’s these underlying woodpecker features that make snake mimicry possible, Kaufman says.

“Even though the wrynecks are not digging holes, they’ve got the woodpecker family characteristics, such as really complex vertebrae,” he says. “Since they’re not pounding on trees, they can put those morphological traits to use in other ways, such as by being contortionists and moving their head in every which way.”

In other words, wrynecks have repurposed their family strengths—which most species use for hammering out homes and digging up grubs—to imitate a snake when they feel threatened. And they did so over thousands of years of evolution that selected for “accidental” snake-like traits, Kaufman says.

“There wasn’t any conscious attempt at the start, like ‘gee, I’ll try to look like this other species,” he says. “Selection is likely favoring wrynecks becoming more and more snake-like, just like in other cases of mimicry.”

And there are plenty of other snake mimics in the animal kingdom. The hawkmoth caterpillar can inflate a serpent head, the mimic octopus has eight limbs that each double as sea snakes, and burrowing owls are known to produce a long, hissing noise. Heck, there are even snakes that imitate snakes.

A Bird for Bewitching

Today, you’d be lucky to spot a wryneck in the woods. They’re elusive, well-camouflaged, and in decline. But centuries ago, its shrill cry might have sent you running.

Due to its odd movements, this humble-looking woodpecker—known then as the jynx bird—was once thought to wield magical, perhaps even evil powers. In fact, that’s where our modern word jinx (“one that brings bad luck”) comes from.

Other sources suggest it was also used for love spells. According to the book Birds: Myth, Lore and Legend, hopeless romantics would nail an open-winged wryneck to a spinning top called an iynx, which they would twirl “amid incantations to excite sexual love.”

Thankfully, that practice has long been retired. But the wryneck’s scientific name, Jynx torquilla (from the Latin torqueo, “to twist”) has forever preserved its spellbinding past and head-turning talent.

 

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