Meg Wyman
Meg Wyman

How a 700-Pound Elk Shrieks Like a Ringwraith

Meg Wyman
Meg Wyman

Nature is fairly consistent when it comes to animal noises. For the most part, bigger animals make bigger and deeper sounds. But there are exceptions, of course. The claws of the little pistol shrimp produce a deadly crack, and the enormous deer species known as wapiti—more commonly called elk—emits a high-pitched shriek that scientists have only just figured out. Their findings are published today in the Journal of Experimental Biology.

The average adult male North American elk (Cervus canadensis) weighs in at about 700 pounds, in a sturdy body topped with dagger-sharp antlers. Looking at this beast, you’d guess that his bellow would be of the earth-rumbling, not earwax-melting kind. You’d be right—and then again, you’d also be wrong.

Here’s the bugling call of an adult male:

Kind of makes your hair stand on end, doesn’t it? For decades, the elk's eerie calls have haunted scientists, who could not explain how it was producing them. Now, one team of researchers believes they’ve found the answer: Elk aren’t really shrieking. They’re whistling.

The researchers traveled to Wyoming, California, and Alberta, Canada during rutting season and videotaped nine males as they bugled. Back in the lab, the team pored over the video images, watching the small movements of the elks' lips, jaws, and nostrils. 

Animal communication expert and co-author Meg Wyman recorded audio of another four males at wapiti farms in New Zealand. Those recordings were then analyzed for frequency, duration, and content.

During this time, the team acquired a recently deceased adult male elk from a park in France. They arranged the animal’s head and neck so that the body was in a bugling posture, then scanned it using computed tomography (CT). After the scans, the elk’s larynx and part of its skull were sent to a zoo in Germany for further analysis.

The audio analysis revealed that the elk’s high-pitched cries reached as high as 4000 Hz. But there was another sound in there, hovering low around 150 Hz—about the frequency you’d expect for the call of an animal that big. The two sounds seemed to behave independently: one sound could waver, while the other remained constant. Unlike a chord, where different notes are sounded together, the sounds seemed to be coming from two places at once.

Examination of the elk's vocal cords revealed them to be the right size and shape for producing a low, reverberating bellow. The source of the shrieks? A hollow pathway from the elk’s throat to its nostrils. By forcing air through the chambers, a male elk can essentially play his own head like a flute.

Rather than alternating between broadcasting two messages, the researchers say, male elk simply play two at once: a low, deep call that can only be heard by other elk nearby, and the creepy shrieks that reverberate over long distances.

Why Do Dogs Crouch Forward When They’re Playing?

Whether they're tilting their heads or exposing their bellies for rubs, dogs are experts at looking adorable. But these behaviors do more than elicit squeals from delighted humans; in many cases, they serve important evolutionary functions. A prime example is the "play bow": If you've ever seen a dog crouch forward with its elbows on the ground and its rear end in the air, wagging tail and all, then you know what it is. The position is the ultimate sign of playfulness, which is important for a species that often uses playtime as practice for attacking prey.

The play bow first evolved in canids as a form of communication. When a dog sees another dog it wants to play with, it extends its front paws forward and lifts up its behind as a visual invitation to engage in a friendly play session. Dogs will "bow" in the middle of playtime to show that they're having fun and wish to continue, or when a session has paused to signal they want to pick it back up. Play bows can also be a sort of apology: When the roughhousing gets too rough, a bow says, “I’m sorry I hurt you. Can we keep playing?”

Play between canines often mimics aggression, and starting off in a submissive position is a way for all participating parties to make sure they’re on the same page. It’s easy to see why such a cue would be useful; the more puzzling matter for researchers is why the ancestors of modern dogs evolved to play in the first place. One theory is that play is crucial to the social, cognitive, and physical development of puppies [PDF]. It’s an opportunity for them to interact with their own kind and learn important behaviors, like how to moderate the strength of their bites. Play also requires the animals to react quickly to new circumstances and assess complex actions from other dogs.

Shiba inus playing outside.
Taro the Shiba Inu, Flickr // CC BY 2.0

Another evolutionary explanation is that playtime prepares puppies for the hunting they do later as adults. Watch two puppies play and you’ll see them stalking, biting, and pouncing on one another—all behaviors canines exhibit in the wild when taking down prey.

Of course, it’s also possible that dogs simply play because it’s fun. This is a strong case for why pet dogs continue to play into adulthood. “Devoting a lot of time to play may be less advantageous for a wild species who spends much of its time hunting or foraging for food, searching for mates, or avoiding predators,” Dr. Emma Grigg, an animal behaviorist and co-author of The Science Behind a Happy Dog, tells Mental Floss. “Many domestic dogs are provisioned by humans, and so have more time and energy to devote to play as adults.”

Because play is a lifelong activity for domestic dogs, owners of dogs of all ages have likely seen the play bow in person. Wild canids, like wolves, foxes, and coyotes, tend to reserve this behavior for members of their own species, but pet dogs often break out the bow for their humans—or anyone else who looks like they might be up for a play session. Grigg says, “One of my dogs regularly play bows to her favorite of our cats.”

Why Crows Hold Noisy Funerals for Their Fallen Friends

The next time you hear a murder of crows cackling for no apparent reason, show a little respect: You may have stumbled onto a crow funeral. Crows are among the few animals that exhibit a social response to a dead member of their species. Though their caws may sound like heartbroken cries, such funerals aren't so much about mourning their fallen friends as they are about learning from their mistakes.

In the video below from the PBS series Deep Look, Kaeli Swift, a researcher at the University of Washington's Avian Conservation Lab, investigates this unusual phenomenon firsthand. She familiarized herself with a group of crows in a Seattle park by feeding them peanuts in the same spot for a few days. After the crows got used to her visits, she returned to the site holding a dead, taxidermied crow and wearing a mask and wig to hide her identity. The crows immediately started their ritual by gathering in the trees and crying in her direction. According to Swift, this behavior is a way for crows to observe whatever might have killed the dead bird and learn to avoid the same fate. Flocking into a large, noisy group provides them protection from the threat if it's still around.

She tested her theory by returning to the same spot the next week without her mask or the stuffed crow. She offered the crows peanuts just as she had done before, only this time the birds were skittish and hesitant to take them from her. The idea that crows remember and learn from their funerals was further supported when she returned wearing the mask and wig. Though she didn't have the dead bird with her this time, the crows were still able to recognize her and squawked at her presence. Even birds that weren't at the funeral learned from the other birds' reactions and joined in the ruckus.

Swift was lucky this group of crows wasn't particularly vengeful. Crows have been known to nurse and spread grudges, sometimes dive-bombing people that have harmed one of their own.

[h/t Deep Look]


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