CLOSE
iStock
iStock

11 Mischievous Facts About Capuchin Monkeys

iStock
iStock

You may not recognize the word capuchin, but you’ve probably seen these spunky little monkeys: They’ve starred in innumerable TV shows, movies, and commercials. But there’s more to them than on-screen fame. They poke each other in the eye as a bonding gesture. They throw rocks at their monkey crushes. Read on to find out more about these remarkable critters.

1. THEY’RE NAMED AFTER THE CAPUCHIN FRIARS—AND SO IS CAPPUCCINO.

In 1525, a Franciscan monk named Matteo da Bascio broke with his order's tradition. He wanted to return to the ways of St. Francis and live a more austere, hermit-like life. Da Bascio helped found a group called the Order of Friars Minor Capuchin, whose members are often called Capuchin monks. They wear a brown pointed hood called a capuccino.

Those friars with the brown hoods were familiar to the European explorers who visited the forests of the new world. When these explorers encountered capuchins in the wild, they couldn’t help but think that those monkeys with hood-like tufts of brown hair looked an awful lot like the Capuchin friars. So, they named them after the Capuchins. The beverage known as cappuccino was probably also named after these coffee-colored robes.

2. ONE SPECIES WAS ONLY RECENTLY REDISCOVERED.

Male golden capuchin in São Paulo Zoo. Image credit: Miguelrangeljr via Wikimedia // CC BY-SA 3.0

Capuchins are a group of small monkeys with long tails that can wrap around tree branches. Their fur comes in a variety of coffee-like shades, from black (like the black-horned capuchin) to caramel (like the golden-bellied capuchin) to cream (like the white-headed capuchin). They fall into two broad categories: tufted and untufted. All are native to Central and South America.

Way back in 1648, a naturalist named Georg Marcgrave published a description [PDF] of a blonde, long-haired capuchin species, but he didn’t collect a specimen, so its identity remained a mystery. More than 350 years later, in 2006, scientists rediscovered Marcgrave’s monkey species in the wild. Dubbed the blonde capuchin (or Sapajus flavius), it’s critically endangered, with just 180 mature individuals left.

3. THEY’RE FAMOUS ON TV.

With their cute faces and charming antics, capuchin monkeys have appeared in all sorts of performances. Victorian organ grinders had capuchins that danced and collected coins. These monkeys were even outfitted in little jockey outfits and made to ride racing greyhounds. More recently, they’ve appeared in movies, such as the Pirates of the Caribbean franchise.

But the most famous capuchin—at least, for Gen Xers—might be Marcel, Ross’s pet monkey from the TV show Friends. Marcel was played by a female monkey named Katie. She has since gone on to appear in other TV shows, movies, and commercials, and she’s the unofficial mascot of the Los Angeles Angels baseball team.

These appearances have prompted people to want pet capuchins. But capuchins are complex and wild, and they can become aggressive, which is why many animal welfare organizations urge people not to keep them as pets. They also get lonely, because …

4. THEY’RE HIGHLY SOCIAL.

Frans de Waal via Wikimedia // CC BY 2.5

Capuchins live in groups. They navigate their social worlds with a complex set of facial expressions and gestures [PDF]. High-ranking males are usually the fathers of all the group’s babies. But they carefully avoid inbreeding; once the dominant male’s daughters grow up, they’ll only mate with lower-ranking males. Capuchins also seem to have a sense of fairness and they avoid individuals who they perceive to be selfish. But before you start drawing too many connections between their behavior and ours, you should know that …

5. THEY POKE EACH OTHER’S EYES TO REINFORCE BONDS.

Professor Susan Perry of UCLA has been studying white-faced capuchins in the jungles of Costa Rica for 25 years. It’s grueling work, she says; “I’m always wet, chewed on, or stung.” But her hard work has paid off. She and her team have observed some amazing monkey business.

Capuchins often invent new behaviors—Dr. Perry calls them traditions—that spread through the group. One of them is, well, shoving your finger in someone else’s eye. Other traditions include sniffing each other’s hands and sucking on tails, fingers, and ears. Capuchins even bite a tuft of hair from another’s face and pass it around with their mouths. This might all be about reinforcing social bonds [PDF]. Just don’t try it with your coworkers.

6. THEY USE TOOLS.

iStock

By now we know that other apes, such as chimpanzees, use tools. But thanks to capuchins, we know that other monkeys do it too. Capuchins were the first non-ape primates that we observed using tools in the wild. Bearded capuchins (look at this male’s handsome beard) skillfully crack nuts using a hammer-like rock and an anvil. Other species use tools, and even the recently rediscovered blonde capuchin has gotten into the act. It fishes termites out of their mounds with a special technique that includes stick rotation and tapping the nests.

7. THEY WASH WITH PEE.

Capuchins and some other New World monkey species do something called “urine washing.” They pee on their hands and use it to wash their feet. Scientists aren’t exactly sure why, but it may be a social cue. Capuchins may urine wash to calm down aggressive friends. Males may do it to appease females or convey their sexual excitement. It may also be about improving a monkey’s grip on slippery trees by making its hands and feet … stickier. Eww.

8. SOME FEMALE CAPUCHINS THROW ROCKS AT CUTE MALES.

Females in a group of bearded capuchins have been observed throwing rocks at males in an apparent attempt to initiate sex. Scientists think that one female might have started the trend, and then other females copied her. See an adorable video of this interaction here.

9. THEY EAT FLOWERS, FROGS, AND MUCH MORE.

iStock

Capuchin diets are pretty varied. They consume both plants and meat. If the season’s right, they’ll dine on plant parts such as fruit, seeds, leaves, and flowers. Their animal prey includes birds, oysters, lizards, frogs, and more. They’ve even been observed eating another species of monkey.

10. ENORMOUS EAGLES EAT THEM.

For a capuchin, life isn’t all fun, games, and eye-poking. Several predators lurk in the forest. Ocelots (small nocturnal wild cats) will prey on them. Snakes are also a threat—though they risk being thwacked by a club-wielding capuchin. But the most impressive predator might be the harpy eagle.

This amazing raptor has claws longer than a grizzly bear’s and a wingspan up to 6.5 feet. They’re deft flyers, even when they’re hunting in dense forests. And they’re patient; they’ll wait hours—sometimes, nearly a day—for the perfect moment to strike.

Female harpy eagles are twice as big as males and they’re better able to take down large prey such as monkeys. They’ll even grab howler monkeys that weigh up to 14 pounds. Other prey items include sloths, porcupines, anteaters, and young pigs and deer.

11. TIMES ARE TOUGH FOR CAPUCHINS.

Miguelrangeljrvia Wikimedia // CC BY-SA 3.0

It’s not clear exactly how many capuchin species there are, but the International Union for the Conservation of Nature lists 17. Of those species, more than half are in serious trouble. Three are listed as endangered and two as near threatened. Four of them are critically endangered, which is the most severe category for extinction risk before “extinct in the wild.” Threats to these monkeys include habitat loss and hunting for meat and for the pet trade.

Let’s protect our capuchin cousins so that they’ll keep cracking open nuts, poking each other in the eye, and throwing rocks at boys for generations to come.

nextArticle.image_alt|e
Scientific Reports, Fernando Ramirez Rozzi
arrow
Stones, Bones, and Wrecks
Humans Might Have Practiced Brain Surgery on Cows 5000 Years Ago
Scientific Reports, Fernando Ramirez Rozzi
Scientific Reports, Fernando Ramirez Rozzi

In the 1970s, archaeologists discovered a site in France containing hundreds of cow skeletons dating back 5000 to 5400 years. The sheer number wasn't surprising—human agriculture in that part of the world was booming by 3000 BCE. What perplexed scientists was something uncovered there a few decades later: a cow skull bearing a thoughtfully drilled hole. Now, a team of researchers has released evidence that suggests the hole is an early example of animal brain surgery.

Fernando Ramírez Rozzi, a paleontologist with the French National Center for Scientific Research, and Alain Froment, an anthropologist at the Museum of Mankind in Paris, published their findings in the journal Nature Scientific Reports. After comparing the opening to the holes chiseled into the skulls of humans from the same era, they found the bones bore some striking similarities. They didn't show any signs of fracturing from blunt force trauma; rather, the hole in the cow skull, like those in the human skulls, seemed to have been carved out carefully using a tool made for exactly that purpose. That suggests that the hole is evidence of the earliest known veterinary surgery performed by humans.

Trepanation, or the practice of boring holes into human skulls, is one of the oldest forms of surgery. Experts are still unsure why ancient humans did this, but the level of care that went into the procedures suggests that the surgery was likely used to treat sick patients while they were still alive. Why a person would perform this same surgery on a cow, however, is harder to explain.

The authors present a few theories, the first being that these ancient brain surgeons were treating a sick cow the same way they might treat a sick human. If a cow was suffering from a neural disease like epilepsy, perhaps they though that cutting a hole in its head would relieve whatever was agitating the brain. The cow would have needed to be pretty special to warrant such an effort when there were hundreds of healthy cows living on the same plot of land, as evidenced by the skeletons it was found with.

Another possible explanation was that whoever operated on the cow did so as practice to prepare them for drilling into the heads of live humans one day. "Cranial surgery requires great manual dexterity and a complete knowledge of the anatomy of the brain and vessel distribution," the authors write in the study. "It is possible that the mastery of techniques in cranial surgery shown in the Mesolithic and Neolithic periods was acquired through experimentation on animals."

Either way, the bovine patient didn't live to see the results of the procedure: The bone around the hole hadn't healed at all, which suggests the cow either died during surgery or wasn't alive to begin with.

nextArticle.image_alt|e
iStock
arrow
Animals
15 Incredible Facts About Pigeons
iStock
iStock

Though they're often described as "rats with wings" (a phrase popularized by the movie Stardust Memories), pigeons are actually pretty cool. From homing instincts to misleading rump feathers, here are 15 things you might not know about these avian adventurers.

1. THEY MIGHT BE THE FIRST DOMESTICATED BIRD.

The common city pigeon (Columba livia), also known as the rock pigeon, might be the first bird humankind ever domesticated. You can see them in art dating back as far as 4500 BCE in modern Iraq, and they've been a valuable source of food for thousands of years.

2. THEY WON OVER CHARLES DARWIN—AND NIKOLA TESLA.

Pigeon-breeding was a common hobby in Victorian England for everyone from well-off businessmen to average Joes, leading to some fantastically weird birds. Few hobbyists had more enthusiasm for the breeding process than Charles Darwin, who owned a diverse flock, joined London pigeon clubs, and hobnobbed with famous breeders. Darwin's passion for the birds influenced his 1868 book The Variation of Animals and Plants Under Domestication, which has not one but two chapters about pigeons (dogs and cats share a single chapter).

Nikola Tesla was another great mind who enjoyed pigeons. He used to care for injured wild pigeons in his New York City hotel room. Hands down, Tesla's favorite was a white female—about whom he once said, "I loved that pigeon, I loved her as a man loves a woman and she loved me. When she was ill, I knew and understood; she came to my room and I stayed beside her for days. I nursed her back to health. That pigeon was the joy of my life. If she needed me, nothing else mattered. As long as I had her, there was a purpose in my life." Reportedly, he was inconsolable after she died.

3. THEY UNDERSTAND SPACE AND TIME.

In a 2017 Current Biology study, researchers showed captive pigeons a series of digital lines on a computer screen for either two or eight seconds. Some lines were short, measuring about 2.3 inches across; others were four times longer. The pigeons were trained to evaluate either the length of the line or how long it was displayed. They found that the more time a line was displayed, the longer in length the pigeon judged it to be. The reverse was true too: If the pigeons encountered a longer line, they thought it existed in time for a greater duration. Pigeons, the scientists concluded, understand the concepts of both time and space; the researchers noted "similar results have been found with humans and other primates."

It's thought that humans process those concepts with a brain region called the parietal cortex; pigeon brains lack that cortex, so they must have a different way of judging space and time.

4. THEY CAN FIND THEIR WAY BACK TO THE NEST FROM 1300 MILES AWAY.

A pigeon flying in front of trees.
iStock

The birds can do this even if they've been transported in isolation—with no visual, olfactory, or magnetic clues—while scientists rotate their cages so they don't know what direction they're traveling in. How they do this is a mystery, but people have been exploiting the pigeon's navigational skills since at least 3000 BCE, when ancient peoples would set caged pigeons free and follow them to nearby land.

Their navigational skills also make pigeons great long-distance messengers. Sports fans in ancient Greece are said to have used trained pigeons to carry the results of the Ancient Olympics. Further east, Genghis Khan stayed in touch with his allies and enemies alike through a pigeon-based postal network.

5. THEY SAVED THOUSANDS OF HUMAN LIVES DURING WORLD WARS I AND II.

Pigeons' homing talents continued to shape history during the 20th century. In both World Wars, rival nations had huge flocks of pigeon messengers. (America alone had 200,000 at its disposal in WWII.) By delivering critical updates, the avians saved thousands of human lives. One racing bird named Cher Ami completed a mission that led to the rescue of 194 stranded U.S. soldiers on October 4, 1918.

6. TWO PIGEONS ALMOST DISTRACTED FROM THE DISCOVERY OF EVIDENCE OF THE BIG BANG.

In 1964, scientists in Holmdel, New Jersey, heard hissing noises from their antenna that would later prove to be signals from the Big Bang. But when they first heard the sound, they thought it might be, among other things, the poop of two pigeons that were living in the antenna. "We took the pigeons, put them in a box, and mailed them as far away as we could in the company mail to a guy who fancied pigeons," one of the scientists later recalled. "He looked at them and said these are junk pigeons and let them go and before long they were right back." But the scientists were able to clean out the antenna and determine that they had not been the cause of the noise. The trap used to catch the birds (before they had to later be, uh, permanently removed) is on view at the Smithsonian Air & Space Museum.

7. YOU CAN TRAIN THEM TO BE ART SNOBS …

Japanese psychologist Shigeru Watanabe and two colleagues earned an Ig Nobel Prize in 1995 for training pigeons, in a lab setting, to recognize the paintings of Claude Monet and Pablo Picasso and to distinguish between the painters. The pigeons were even able to use their knowledge of impressionism and cubism to identify paintings of other artists in those movements. Later, Watanabe taught other pigeons to distinguish watercolor images from pastels. And in a 2009 experiment, captive pigeons he'd borrowed were shown almost two dozen paintings made by students at a Tokyo elementary school, and were taught which ones were considered "good" and which ones were considered "bad." He then presented them with 10 new paintings and the avian critics managed to correctly guess which ones had earned bad grades from the school's teacher and a panel of adults. Watanabe's findings indicate that wild pigeons naturally categorize things on the basis of color, texture, and general appearance.

8. … AND TO DISTINGUISH WRITTEN WORDS.

In a 2016 study, scientists showed that pigeons can differentiate between strings of letters and actual words. Four of the birds built up a vocabulary of between 26 and 58 written English words, and though the birds couldn't actually read them, they could identify visual patterns and therefore tell them apart. The birds could even identify words they hadn't seen before.

9. FLUFFY PIGEON FEET MIGHT ACTUALLY BE PARTIAL WINGS.

A white pigeon with curly feathers and fluffy feet.
iStock

A few pigeon breeds have fuzzy legs—which hobbyists call "muffs"—rather than scaly ones. According to a 2016 study, the DNA of these fluffy-footed pigeons leads their hind legs to take on some forelimb characteristics, making muffed pigeon legs look distinctly wing-like; they're also big-boned. Not only do they have feathers, but the hindlimbs are somewhat big-boned, too. According to biologist Mike Shapiro, who led the study, "pigeons' fancy feathered feet are partially wings."

10. SOME PIGEONS DISTRACT FALCONS WITH WHITE RUMP FEATHERS.

In a life-or-death situation, a pigeon's survival could depend upon its color pattern: Research has shown that wild falcons rarely go after pigeons that have a white patch of feathers just above the tail, and when the predators do target these birds, the attacks are rarely successful.

To figure out why this is, Ph.D. student Alberto Palleroni and a team tagged 5235 pigeons in the vicinity of Davis, California. Then, they monitored 1485 falcon-on-pigeon attacks over a seven-year span. The researchers found that although white-rumped pigeons comprised 20 to 25 percent of the area's pigeon population, they represented less than 2 percent of all the observed pigeons that were killed by falcons; the vast majority of the victims had blue rumps. Palleroni and his team rounded up 756 white- and blue-rumped pigeons and swapped their rump feathers by clipping and pasting white feathers on blue rumps, and vice versa. The falcons had a much easier time spotting and catching the newly blue-rumped pigeons, while the pigeons that received the white feathers saw predation rates plummet.

Close observation revealed that the white patches distract birds of prey. In the wild, falcons dive-bomb other winged animals from above at high speeds. Some pigeons respond by rolling away in midair, and on a spiraling bird, white rump feathers can be eye-catching, which means that a patch of them may divert a hungry raptor's focus long enough to make the carnivore miscalculate and zip right past its intended victim.

11. DODOS WERE RELATED TO TODAY'S PIGEONS.

Two blue and green Nicobar pigeons.
iStock

Though most of this list focuses on the rock pigeon, there are 308 living species of pigeons and doves. Together, they make up an order of birds known as the columbiformes. The extinct dodo belonged to this group as well.

Flightless and (somewhat) docile, dodos once inhabited Mauritius, an island near Madagascar. The species had no natural predators, but when human sailors arrived with rats, dogs, cats, and pigs, it began to die out, and before the 17th century came to a close, the dodo had vanished altogether. DNA testing has confirmed that pigeons are closely related to the dodo, and the vibrant Nicobar pigeon (above) is its nearest genetic relative. A multi-colored bird with iridescent feathers, this near-threatened creature is found on small islands in the South Pacific and off Asia. Unlike the dodo, it can fly.

12. AT ONE POINT, MORE THAN ONE-QUARTER OF ALL THE BIRDS LIVING IN THE U.S. MAY HAVE BEEN PASSENGER PIGEONS.

Wild/feral rock pigeons reside in all 50 states, which makes it easy to forget that they're invasive birds. Originally native to Eurasia and northern Africa, the species was (most likely) introduced to North America by French settlers in 1606. At the time, a different kind of columbiform—this one indigenous—was already thriving there: the passenger pigeon (Ectopistes migratorius). As many as 5 billion of them were living in America when England, Spain, and France first started colonizing, and they may have once represented anywhere from 25 to 40 percent of the total U.S. bird population. But by the early 20th century, they had become a rare sight, thanks to overhunting, habitat loss, and a possible genetic diversity issue. The last known passenger pigeon—a captive female named Martha—died on September 1, 1914.

13. THEY'RE REALLY GOOD AT MULTITASKING.

According to one study, they're more efficient multitaskers than people are. Scientists at Ruhr-Universitat Bochum put together a test group of 15 humans and 12 pigeons and trained all of them to complete two simple jobs (like pressing a keyboard once a light bulb came on). They were also put in situations wherein they'd need to stop working on one job and switch over to another. In some trials, the participants had to make the change immediately. During these test runs, humans and pigeons switched between jobs at the same speed.

But in other trials, the test subjects were allowed to complete one assignment and then had to wait 300 milliseconds before moving on to the next job. Interestingly, in these runs, the pigeons were quicker to get started on that second task after the period ended. In the avian brain, nerve cells are more densely packed, which might enable our feathered friends to process information faster than we can under the right circumstances.

14. PIGEONS PRODUCE FAKE "MILK."

Only mammals produce genuine milk, but pigeons and doves (along with some other species of birds) feed their young with something similar—a whitish liquid filled with nutrients, fats, antioxidants, and healthy proteins called "crop milk." Both male and female pigeons create the milk in the crop, a section of the esophagus designed to store food temporarily. As is the case with mammal milk, the creation of crop milk is regulated by the hormone prolactin. Newly-hatched pigeons drink crop milk until they're weaned off it after four weeks or so. (And if you've ever asked yourself, "Where are all the baby pigeons?" we have the answer for you right here.)

15. ONE STUDY SUGGESTS THAT, GIVEN THE RIGHT CONDITIONS, THEY'RE AS GOOD AT IDENTIFYING CANCER AS DOCTORS.

We've already established that pigeons are excellent at differentiating between artists and words, but a 2015 study revealed they can also distinguish between malignant and benign growths in the right conditions. Researchers at University of California Davis Medical Center put 16 pigeons in a room with magnified biopsies of potential breast cancers. If the pigeons correctly identified them as either benign or malignant, they got a treat, According to Scientific American.

"Once trained, the pigeons' average diagnostic accuracy reached an impressive 85 percent. But when a "flock sourcing" approach was taken, in which the most common answer among all subjects was used, group accuracy climbed to a staggering 99 percent, or what would be expected from a pathologist. The pigeons were also able to apply their knowledge to novel images, showing the findings weren't simply a result of rote memorization."

Mammograms proved to be more of a challenge, however; the birds could memorize signs of cancer in the images they were trained on but could not identify the signs in new images.

No matter how impressive their results, "I don't anticipate that pigeons, no matter how good they become at pathology or radiology, will be playing a role in actual patient care—certainly for the foreseeable future," study co-author Richard M. Levenson told Scientific American. "There are just too many regulatory barriers—at least in the West."

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios