M. Haslam
M. Haslam

Brazilian Monkeys Make Stone Hammers That Look a Lot Like Early Human Tools

M. Haslam
M. Haslam

Animals are adorable when they do people things. It’s a scientific fact. But the list of “people things” just keeps on shrinking. Other animals can hold grudges, name their babies, read our expressions, and even read our mammogram results. The latest ding in our dominance comes courtesy of Brazilian capuchin monkeys, who, as it turns out, have been sharpening stones into human-style hammers for a long, long time. A report on the findings was published in the journal Nature.

Researchers in Brazil have had their eye on the bearded capuchin (Sapajus libidinosus) for some time now and have found that despite a varied diet, the little monkeys expend a lot of energy acquiring one particular food: cashews. To access the sweet meat inside the cashew’s tough shell, capuchins developed their own specialized tools, which they’ve been using now for at least 700 years.

The team now reports that those same monkeys may have been inadvertently messing with the timeline of human events. In addition to their cashew bashing, the researchers say, the capuchins will also pound one rock against another. This stone-on-stone percussion (as the researchers call it) chips away pieces of both rocks, sharpening them in the process—and producing results that look an awful lot like early human cutting tools.

The researchers couldn’t tell why the monkeys were smashing rocks. They did use some of the newly broken stones as hammers, but they didn’t use the sharpened parts. About half of the time after breaking a rock, a monkey mason would lick or sniff it, which suggests that they might be after essential minerals they can’t get any other way.

These findings have pretty substantial implications for both primate evolution and archaeological research. Before this, hominins (the group of primates that includes humans and our human-like ancestors) were the only known animals to make this type of tool.

“Our understanding of the new technologies adopted by our early ancestors helps shape our view of human evolution,” co-author Michael Haslam of the University of Oxford said in a statement. “The emergence of sharp-edged stone tools that were fashioned and hammered to create a cutting tool was a big part of that story. The fact that we have discovered monkeys can produce the same result does throw a bit of a spanner in the works.”

It also makes scientists wonder about certain caches of tools allegedly made by early humans. In an accompanying commentary in the same issue of Nature, paleontologist Hélène Roche called the research a “shattering discovery.” She noted that we have plenty of corroborating evidence showing that artifacts from the Early African Stone Age were indeed made by people. But there have been some questions about the origin of tools from the Late Pleistocene epoch (between 40,000 and 20,000 years ago), and the answer might well be “monkeys.”
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These Sparrows Have Been Singing the Same Songs for 1500 Years

Swamp sparrows are creatures of habit—so much so that they’ve been chirping out the same few tunes for more than 1500 years, Science magazine reports.

These findings, published in the journal Nature Communications, resulted from an analysis of the songs of 615 adult male swamp sparrows found in six different areas of the northeastern U.S. Researchers learned that young swamp sparrows pick up these songs from the adults around them and are able to mimic the notes with astounding accuracy.

Here’s what one of their songs sounds like:

“We were able to show that swamp sparrows very rarely make mistakes when they learn their songs, and they don't just learn songs at random; they pick up commoner songs rather than rarer songs,” Robert Lachlan, a biologist at London’s Queen Mary University and the study’s lead author, tells National Geographic.

Put differently, the birds don’t mimic every song their elders crank out. Instead, they memorize the ones they hear most often, and scientists say this form of “conformist bias” was previously thought to be a uniquely human behavior.

Using acoustic analysis software, researchers broke down each individual note of the sparrows’ songs—160 different syllables in total—and discovered that only 2 percent of sparrows deviated from the norm. They then used a statistical method to determine how the songs would have evolved over time. With recordings from 2009 and the 1970s, they were able to estimate that the oldest swamp sparrow songs date back 1537 years on average.

The swamp sparrow’s dedication to accuracy sets the species apart from other songbirds, according to researchers. “Among songbirds, it is clear that some species of birds learn precisely, such as swamp sparrows, while others rarely learn all parts of a demonstrator’s song precisely,” they write.

According to the Audubon Guide to North American Birds, swamp sparrows are similar to other sparrows, like the Lincoln’s sparrow, song sparrow, and chipping sparrow. They’re frequently found in marshes throughout the Northeast and Midwest, as well as much of Canada. They’re known for their piercing call notes and may respond to birders who make loud squeaking sounds in their habitat.

[h/t Science magazine]

ZUMA Press, Inc., Alamy
5 Fascinating Facts About Koko the Gorilla
ZUMA Press, Inc., Alamy
ZUMA Press, Inc., Alamy

After 46 years of learning, making new friends, and challenging ideas about language, Koko the gorilla died in her sleep at her home at the Gorilla Foundation in Woodside, California on June 21, 2018. Koko first gained recognition in the late 1970s for her ability to use sign language, but it was her friendly personality that made her a beloved icon. Here are five facts you should know about the history-making ape.


Francine "Penny" Patterson, then a graduate student at Stanford University, was looking for an animal subject for her inter-species animal communication experiment in the early 1970s when she found a baby gorilla at the San Francisco Zoo. Originally named Hanabiko (Japanese for "fireworks child," a reference to her Fourth of July birthdate), Koko took to signing quickly. Some of the first words Koko learned in "Gorilla Sign Language," Patterson's modified version of American Sign Language, were "food," "drink," and "more." She followed a similar trajectory as a human toddler, learning the bulk of her words between ages 2.5 and 4.5. Eventually Koko would come to know over 1000 signs and understand about 2000 words spoken to her in English. Though she never got a grasp on grammar or syntax, she was able to express complex ideas, like sadness when watching a sad movie and her desire to have a baby.


Not only did Koko use language to communicate—she also used it in a way that was once only thought possible in humans. Her caretakers have reported her signing about objects that weren't in the room, recalling memories, and even commenting on language itself. Her vocabulary was on par with that of a 3-year-old child.


Koko was the most famous great ape who knew sign language, but she wasn't alone. Michael, a male gorilla who lived with Koko at the Gorilla Foundation from 1976 until his death in 2000, learned over 500 signs with help from Koko and Patterson. He was even able to express the memory of his mother being killed by poachers when he was a baby. Other non-human primates have also shown they're capable of learning sign language, like Washoe the chimpanzee and Chantek the orangutan.


Koko received many visitors during her lifetime, including some celebrities. When Robin Williams came to her home in Woodside, California in 2001, the two bonded right away, with Williams tickling the gorilla and Koko trying on his glasses. But perhaps her most famous celebrity encounter came when Mr. Rogers paid her a visit in 1999. She immediately recognized him as the star of one of her favorite shows, Mister Rogers' Neighborhood, and greeted him by helping him take off his shoes like he did at the start of every episode.


Koko was never able to have offspring of her own, but she did adopt several cats. After asking for a kitten, she was allowed to pick one from a litter for her birthday in 1985. She named the gray-and-white cat "All Ball" and handled it gently as if it were her real baby, even trying to nurse it. She had recently received two new kittens for her 44th birthday named Ms. Gray and Ms. Black.


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