Extraordinary claims, Carl Sagan liked to say, require extraordinary evidence. Here is an extraordinary claim: "Chimpanzeelike violence preceded and paved the way for human war, making modern humans the dazed survivors of a continuous, five-million-year habit of lethal aggression." The anthropologist Richard Wrangham of Harvard University made this statement in his 1996 book Demonic Males: [...]

A long-in-place loophole that exempted captive-bred chimpanzees from the full protections of the Endangered Species Act may finally be closed, Dan Ashe, director of the U.S. Fish and Wildlife Service (FWS), announced on June 11. For decades now, wild-born chimpanzees (Pan troglodytes) have been classified as “endangered” under the Endangered Species Act (ESA). Captive-born chimps, [...]

As tens of thousands of refugees crowd into the area around Virunga National Park in the warn-torn Democratic Republic of the Congo (DRC), the animals that already lived there are getting squeezed out their native habitats. Some of them apparently aren’t too happy about it. Incidents of chimpanzee attacks on humans are reportedly on the [...]

When a wild animal is rescued from poachers or wildlife smugglers, conservationists usually make an effort to rehabilitate it and return it to life in its native habitat. But what if the animal contracted a disease from humans during captivity that could then be transmitted back to the rest of its species? Should that animal [...]

His name is Clay. He’s a happy, creative 24-year-old male who prefers to live in solitude. Although most of the time he is peaceful, he has been known to become aggressive and violent in a manner that can terrify the people who love him. If Clay were human, he would probably have been diagnosed with [...]

In a move that’s probably long overdue, the U.S. Fish and Wildlife Service (FWS) announced last week that it will conduct a status review to determine if captive chimpanzees (Pan troglodytes) should be reclassified from “threatened” to the more protected status “endangered” under the Endangered Species Act (ESA). Wild-born chimpanzees have been fully protected under [...]

Earlier this month, scientists for the Pan African Sanctuaries Alliance presented new research that predicted the extinction of the Nigeria-Cameroon chimpanzee (Pan troglodytes ellioti), the world’s rarest chimpanzee subspecies, within as little as 20 years. Now, just a few weeks later, a conservation plan written by primate experts from 17 conservation groups and government agencies [...]

DNA testing could be used as a tool to help fight smuggling of endangered chimpanzees, according to a study published this week in the journal BMC Ecology. Although they are still the most common apes in Africa, chimpanzees (Pan troglodytes and their related subspecies) have experienced population drops of around 75 percent in the past [...]

Tanzania’s chimpanzee population has plummeted by more than 90 percent, from 10,000 a few years ago to just 700 today, according to a report from the Tanzania National Parks Authority. The Parks Authority blamed disease and predation — by humans and other mammals — for the dramatic losses. The country’s chimpanzees are located in just [...]

The most important sign language study done with an ape was surely the first one back in the 1960s, with Washoe, for it established that chimpanzees can use American Sign Language (ASL). The most decisive such study, however, was probably the one a decade later, with Nim Chimsky because it put a halt to such [...]

With one misstep and the snap of a trap, Tinka was broken. The 50-year-old chimpanzee’s hands were mangled and left severely deformed and almost useless. Most of the muscles of his left wrist were paralyzed, and he was left with a limited range of movement. His left hand just sat there in a hooked position, [...]

Editor’s Note: This post is the third in a four-part series of essays for Scientific American by primatologist Frans de Waal on human nature, based on his ongoing research. (The first post, on our sense of fairness, can be read here, and a second post, on the impact of crowding, is here.) De Waal and [...]

We are thrilled to pass along the news that Scientific American has won this year’s prestigious Science in Society award, given by the National Association of Science Writers, for the essay Ban Chimp Testing that appeared online and in our October 2011 issue. The article made the argument that medical testing caused such psychological harm [...]

Chimpanzees are mostly peaceable creatures, spending much of their time foraging for food and grooming each other. But occasionally they kill their own kind. Why they engage in these lethal bouts of aggression has been uncertain. One theory holds that killing is an evolved strategy for reducing competition for resources; another posits that human disturbance—including [...]

Relative to our ape brethren, humans give birth to really big babies. This especially substantial infant size—along with newborns’ large heads and general helplessness—helped to spur the development of more advanced social systems to help mother and child safe, researchers think. A new study examines the evolution of this trend to try to pinpoint when [...]

[It's with great pleasure the Symbiartic team is featuring this Guest Post by illustrator Nathaniel Gold. Gold is the artist behind the wonderful illustrations found on The Primate Diaries by Eric Michael Johnson, and has twice been featured as Image of the Week (once, twice) here on the Scientific American Blog Network. I was excited [...]

A juvenile chimpanzee in the Ivory Coast’s Tai Forest watches as her mother carefully places a soft coula nut onto a hard, flat rock. In her other hand, mom has a chunk of hard wood. Mom smashes the nut with her makeshift hammer, once, twice, three times. Having broken the outer shell, she plucks out [...]

Sometimes, zoo animals behave unnaturally. Most animals on display at zoos are not really designed for captive living. If you’ve been to a zoo, no doubt you’ve noticed evidence of this: a tiger who paces back and forth, or a monkey that does nothing but circle the enclosure. Life in captivity can even result in [...]

When is a yawn just a yawn? When is a yawn more than a yawn? Contagious yawning – the increase in likelihood that you will yawn after watching or hearing someone else yawn – has been of particular interest to researchers in fields as varied as primatology, developmental psychology, and psychopathology. At first, scientists thought [...]

Chimpanzees have a bad reputation. Maybe it’s because humans have a thing about wanting to feel unique among primates. Some have argued that humans are the only species that truly behaves altruistically, the only species that actively helps out other individuals even when there is no direct benefit. Despite mounting evidence that other animals, including [...]

Lots of people mistake bonobos for chimpanzees, despite the fact that they’re really two different species. But that people are familiar with chimpanzees in the first place is actually somewhat remarkable, given how rare these primates truly are. The IUCN’s most recent estimate (in 2003) for the global population of wild chimpanzees is only 172,700 [...]

Can dogs pretend? This is the question I asked yesterday, prompted by Sheril’s story: …this afternoon Happy did something unusual. She carried a toy frog over to her water bowl, and gently put it down as pictured. Given its orientation, I’m skeptical that her placement was an accident. The frog continues to sit like this [...]

What is culture? One simple definition might be: a distinctive behavior shared by two or more individuals, which persists over time, and that ignorant individuals acquire through socially-aided learning. There are at least four different ways to learn a particular behavior or problem-solving strategy. That is to say, there are four different ways to learn. [...]

Editor’s Note: While I’m on vacation, I’ve arranged a series of guest posts from other writers who routinely cover animal behavior and cognition. Today’s post, about the controversial mirror self-recognition test in primates, comes from the blogger at Serious Monkey Business. Follow her on twitter: @SrsMonkeyBiz. I have a confession: one of my favorite things [...]

Dogs are particularly good at tasks that involve communicating or cooperating with humans, which has led some researchers to speculate that they are really good at solving social tasks, more generally. For example, dogs can figure out where a human’s attention is, are really good at picking up on eye-gaze and finger pointing cues, distinguish [...]

What is culture? One simple definition might be: a distinctive behavior shared by two or more individuals, which persists over time, and that ignorant individuals acquire through socially-aided learning. There are at least four different ways to learn a particular behavior or problem-solving strategy. That is to say, there are four different ways to learn. [...]