Captive Animals Act Smarter

In the Kenyan wilderness, hyenas facing a meat-stuffed puzzle box performed impressively—impressively badly, that is. Researchers expected the animals to be up to the challenge, but few of them ever got the box open. Now, repeating the experiment with captive hyenas, they've discovered that there's no contest: the captive animals are better problem solvers.

Out of 62 wild hyenas in last year's study, less than 15 percent ever managed to slide the latch and swing open the door of the barred metal box. Despite multiple chances, most of the animals were losers in this game.

But lead author Sarah Benson-Amram observed certain behavioral traits shared by the winners. Hyenas that tried more techniques to get the box open (biting, dragging, flipping the darn thing over) had greater odds of success. And hyenas that were less "neophobic"—that is, less wary when approaching a new object in their environment—also did better.

Previous studies with primates and birds had suggested that captive animals are both less neophobic and better at problem solving than wild ones. So Benson-Amram repeated her experiment on a group of hyenas living very far from their homeland, in Berkeley, California.

This group was smaller than the wild hyena group, with only 19 animals tested. But three-quarters of them solved the puzzle, Benson-Amram reports in Animal Behaviour. And every successful captive hyena got the meat on its first try—unlike the wild animals, most of which needed more than one trial before they figured it out.

Although the wild and captive animals belonged to the same species, you would get very different impressions of hyenas' problem-solving smarts if you only looked at one group.

Benson-Amram ruled out a few possible explanations for that difference. Did well-fed animals have more energy for solving the puzzle? In the wild, high-ranking hyenas ate more but didn't do any better with the puzzle box. Were hungrier animals more motivated? Skinny hyenas had no advantage either, and captive hyenas didn't lose interest after eating.

Two explanations, though, held up. One was neophobia. In the wild, animals that were more cautious about approaching the manmade box were less likely to crack it open. Captive animals were overall less neophobic than wild ones. This isn't surprising, since they're used to living around humans and our metal objects.

The second notable difference was that captive hyenas tended to try more behaviors (biting, digging, pulling, and so on) than wild hyenas did. Benson-Amram thinks this has to do with distraction.

"It’s almost akin to giving a puzzle to a civilian in an active war zone versus giving one to a person in the comfort of their living room," she says. The wild hyena is busy watching out for predators, rather than wondering whether pushing and biting at the same time might get this box open. "The person in the war zone would likely give much less mental focus to the puzzle since they have to constantly look over their shoulder," Benson-Amram says.

Or maybe the comfortable home isn't the right analogy for the captive hyenas.

"Imagine giving a puzzle to a person in solitary confinement," Benson-Amram says. "That person may be much more excited about the puzzle and interested in solving it than the person in their living room who has TV, books, their family, and other fun diversions." She adds, "I am not trying to say that zoos are as bad as solitary confinement." But captive hyenas clearly live in a more predictable, less stimulating environment than the Kenyan savannah.

Not all the hyenas learned how to open the box. But scientists learned something that might be critical. When researchers are wondering about the "maximum cognitive abilities" of a species, Benson-Amram says, captive animals may be better subjects. When they want to know what a species is capable of in the wild, though, they should remember that it's a war zone out there.

Benson-Amram, S., Weldele, M., & Holekamp, K. (2012). A comparison of innovative problem-solving abilities between wild and captive spotted hyaenas, Crocuta crocuta Animal Behaviour DOI: 10.1016/j.anbehav.2012.11.003

Image and video courtesy of MSU.

Why Humans Prefer Not to Gallop

As kids, we discover that our two legs can manage many different gaits. After walking and running we figure out how to tiptoe, hop, and skip. (Personally, I decided at one point to become a better skipper than anyone I knew, practicing backward skipping and figure-eights in our driveway. I may have sensed that my competition in this pursuit was not very stiff.)

For basic getting around, we usually settle on walking and running. But why do we ignore so much of our bipedal repertoire in favor of locomotion that's more, well, pedestrian? Researchers in Belgium asked this question about one gait in particular: the gallop.

In case you missed this one as a kid, the human version of a gallop involves holding one leg always in front of the body and the other leg always behind. Bounding along, you create an uneven rhythm of footfalls: ba-DUM, ba-DUM, ba-DUM.

"Gallop is, though rarely used, a familiar gait for humans," the authors write in the Journal of Experimental Biology. People may start galloping spontaneously under certain (infrequent) circumstances, such as going quickly downhill.

For their study, lead author Pieter Fiers of the University of Antwerp and his colleagues had a dozen volunteers run and gallop down a hallway, then dissected their motion in great detail. Platforms that lined the hallway measured the force people produced in their steps. The subjects were covered in motion-capture markers, like Avatar actors. Finally, a separate group of subjects did their running and galloping on a treadmill while the researchers measured how much oxygen they used and carbon dioxide they gave off.

People preferred to gallop at pretty much the same speed they ran. But the length of a galloping stride was shorter than a running stride—so gallopers had to take more steps, and do more work, to travel at the same speed as runners.

Gallopers exerted that effort unevenly, with the front leg doing more work than the back leg. And the galloping stride, researchers saw, demanded more from the hips than running did. This tired people out quickly. Out of 12 treadmill gallopers in the study, 4 gave up before the end of their 4-minute session, complaining of fatigue and stress in their hips and thighs. (An intended 13th galloper couldn't figure out how to gallop on the treadmill belt in the first place.)

When researchers calculated their subjects' metabolic rates, they found that galloping was about 24% more costly than running at the same speed. In other words, galloping burns up more energy, takes more effort, and is less comfortable than running. It's no wonder we don't usually opt for it.

Still, the fact that we're not efficient at galloping means it would be a tougher workout than running. Maybe athletes should start mixing some alternative gaits into their usual exercise routines. Who knows—with practice, you might become the best galloper in the whole world.


Fiers P, De Clercq D, Segers V, & Aerts P (2012). Biomechanics of human bipedal gallop: asymmetry dictates leg functions. The Journal of experimental biology PMID: 23239890

Image: Devon D'Ewart (Flickr)

12 Days of Inkfish, Day 12: Cuddlefish

Sometimes a cuttlefish wants to cuddle, and sometimes it wants to attack you with its face and ingest you whole. Both sides of the cephalopod's personality are on display in this video from the BBC. Also on display: the giant cuttlefish's unbelievable full-body strobe light effect. This is an animal you want to stay on the good side of.

Thanks for celebrating the 12 Days of Inkfish with me! Next week, regularly scheduled programming will return. Stay tuned for new science and new marveling at nature's old—but spectacular—tricks.

Until then, did you miss any of these?

Day 1: What happens when inkfish receive gifts
Day 2: Life as an upside-down jelly
Day 3: Head explosions and a reverse sun
Day 4: The help desk answers "orangutan stop following me" and other reader questions
Day 5: A video of grebes running on water to prove their commitment
Day 6: How Zion Canyon is like the Princess and the Pea
Day 7: Which posts won Best Mustache and other superlatives in the 2012 yearbook
Day 8: This nebula is a square peg in a round universe, thank goodness
Day 9: These airport worms are hard at work eating your garbage
Day 10: Sending you all on an acoustic scavenger hunt (please report back!)
Day 11: The most charming breeds of purse animals

Image: Screenshot from "Animal mating rituals of giant cuttle fish in the blue Australian ocean waters" by BBC Worldwide

12 Days of Inkfish, Day 11: Purse Animals

Ordinarily, I would use "purse animal" to describe one of the low-weight-class dog breeds that city dwellers carry around in designer shoulder bags. In this case, though, the animals aren't inside Louis Vuitton purses—they're made of them.

For the opening of a new London store in 2010, Louis Vuitton commissioned British artist Billie Achilleos to create a series of animal sculptures. The creatures would be made entirely from leather purses and other accessories. With the fashion house's blessing, the artist began hacking up some pricey bags.

The first set of animals went into glass dome jars in a window display in the new store. Having been sufficiently charmed, Louis Vuitton commissioned even more purse creatures the next year for the launch of its bag-monogramming service.

Achilleos wrote on her blog about choosing the materials for each animal carefully. A noisy grasshopper was made from "products with zips and poppers that make satisfying noises." To build the pragmatic beaver, she used men's wallets and bags. 

Scroll through the complete set of purse animals at Louis Vuitton's Facebook album. There's also a making-of video on Billie Achilleos's blog. She created a zoo's worth of creatures, ranging from chameleon to puppy. This kind of purse dog, though, doesn't yap.

Images copyright Patrick Gries 2010, via Facebook.

12 Days of Inkfish, Day 10: Acoustic Scavenger Hunt

On the beach of a tiny Scottish island, a person kicked and jumped through unusual "singing sands" that made a squeaky barking sound in response. More than 3,600 miles away, I was able to eavesdrop on the weird phenomenon because that person had uploaded a recording to the website Sound Around You.

This crowdsourced sound map is a project by researchers at the University of Salford in Manchester. Volunteers around the world have shared ambient noises or noteworthy moments from their environments. The researchers hope to learn about how our soundscapes make us feel, and how they affect our lives.

Exploring the map they've built so far, you can hear street music in Chile, a quiet countryside in Thailand, and chatter on an Italian bus. From Israel, someone has uploaded the wail of an air-raid siren. Once you start cupping your ear toward people and streets on the other side of the world, it's hard to turn away.

The ambient noises of wind and elevated trains in Chicago seem to be pretty well covered already. But if you live someplace with more interesting background noise, you can use a free app called i-SAY to capture (and share) the sounds around you.

Image: Sound Around You

12 Days of Inkfish, Day 9: Airport Worms

While you were vacationing on New Year's Day, nearly two million worms were working hard at Charlotte Douglas International Airport. The airport installed them in the fall of 2012 as part of its new recycling center. By munching through passengers' coffee grounds, used paper towels, and uneaten French fries, the worms are making garden fertilizer out of what used to be landfill fodder.

At the recycling center, employees first sort through the airport's 25 daily tons of trash. Recyclables such as cardboard, aluminum, and plastic are sold. (One airline, project director Bob Lucas said in November, discards entire sleeves of plastic cups even if only a few were used during a flight.) Clothing, which Lucas said panicked passengers dump in the trash when their bags are overweight, is collected by a "group of ladies" who clean and donate it.

As for the worm food itself, it gets heated and pre-composted before finally going to the red wigglers. The airport plans to use waste from the worms to fertilize its grounds. The slimy new employees are happy and—now that Lucas has figured out how to stop them fleeing during a thunderstorm—seem to plan on staying at their jobs.

Image: Sparrows' Friend (via Flickr). Thanks to Leigh for the tip!

12 Days of Inkfish, Day 8: Square Peg in a Round Universe

We can all agree there's too much round stuff in space, right? All those planets and stars and orbital paths and moon craters and disks of debris get old. The most variation you can usually hope for is an astroid shaped like a potato.

Here, for some relief, is the aptly named Red Square nebula. Researchers Peter Tuthill of Sydney University and James Lloyd of Cornell University created this image of the cloud, which surrounds a star called MWC 922.

The researchers think its square shape might be due to a lucky viewing angle on our part. The nebula may really be two cones of gas pointing outward, as if the star at the center were a cheerleader holding a giant megaphone in either hand. From our angle, the nebula looks like a giant X or square. If it turned 90 degrees, we'd find ourselves facing—yet again—some round stuff in space.

Image: Peter Tuthill, Sydney University Physics Dept., Palomar and W.M. Keck observatories (via APOD)