In 1967, local villagers in Africa’s Equitorial Guinea captured a remarkable baby gorilla with a coat of pure white. The film tells the story of this amazing animal, from his loving upbringing by humans to his eventual death from skin cancer in 2003. It also tracks the revolutionary changes in our understanding of how best to care for gorillas that have taken place during Snowflake’s lifetime. Buy the DVD. This film premiered February 19, 2005.

This program premiered February 23, 1997.

It turns out human beings aren’t so unique after all. Conventional wisdom once held that humans were the only animals that could make and use tools. Then, researchers discovered that some of our closest relatives, such as chimpanzees and some monkeys, made and used tools too.

Now it turns out that chimps and humans have something else in common: the capacity to kill, and not just for food. In the 1970s, primate researchers shocked many people with the news that chimpanzees hunted and killed colobus monkeys. Then came even more stunning news: Chimps killed, and sometimes ate, their own kind too.

Today, many scientists believe the hunts are a form of organized violence that plays an important role in chimp culture. One of the researchers studying these seemingly ritualized hunts is David Watts, a primatologist and anthropologist at Yale University in New Haven, Connecticut, who is featured in NATURE’s Deep Jungle: The Beast Within. NATURE spoke with Watts about his studies.

How did you get involved in studying chimp violence?

I got into it because I am interested in human evolution and how our behaviors evolved. I first worked with mountain gorillas in Rwanda. Then, [at the suggestion of another scientist,] in the summer of 1993 I went for the first time to study chimps at Ngogo, in Uganda’s Kibale National Park. It has one of the biggest known chimp communities in the world, now 140 to 150 animals, and they appear to be in the midst of a baby boom! It’s possible we will have 19 births this year, so it turns out to be a fantastic place to observe chimp behavior.

What have you seen?

Well, one of the most fascinating behaviors is chimpanzee hunting. It’s incredible to follow a group of chimps and watch them catch colobus monkeys and just go to work on them, sharing the meat. We’ve also observed groups of male chimps going on patrol and being pretty nasty to their neighbors. Since we’ve been there, we’ve documented chimps killing at least seven infant chimps, four adult males, and one juvenile chimp. Other times, they have beaten up females pretty badly.

Why do they do it?

It appears to be a regular part of chimp behavior, although it can vary from population to population and habitat to habitat. And like other forms of aggression, they use it tactically. For instance, we might be following a group of males, and they will switch into what we call patrol mode. They’ll go silent, which is unusual for chimps, and just look and listen. When they hear neighboring chimps, they respond in a pretty predictable way. If there are just a few chimps in the group, for instance, they’ll quietly move back toward the center of their own territory. If it’s a big group, they’ll respond vocally and listen to the responses. If they decide they are evenly matched, that can lead to major aggression. They’ll chase down, surround, and attack rivals. Sometimes they kill them.

Do they eat the meat?

Chimps that are successful hunters may be eating more meat than some Ugandans. But they don’t eat adult chimps, although they will cannibalize the infants. [And even when the prey is a monkey], often chimps don’t eat much of the meat. That raises the question of whether the hunts have more important social significance. For instance, we’ve seen active meat sharing among coalitions of the chimpanzees. If one chimp has a big hunk of meat, and another chimp comes along, [the first chimp] may put a piece of meat into their hand. So it may be a way to build relationships.

So, is this chimp warfare?

I don’t personally use the term “warfare” with chimps. It’s different. Humans are a lot more complicated, and I have to remind myself regularly that the thoughts I’m putting in [a chimp's] mind aren’t the ones it’s having. But chimp behavior may give us some insight in[to] the evolution of human behavior.

In the forests of the Central African Republic, Italian primatologist Chloe Cipolletta is trying to make friends. Cipolleta isn’t seeking ordinary companions; she’s trying to befriend a group of western lowland gorillas in order to learn more about how to protect these endangered and poorly understood primates.

“I was born with a passion for animals and nature,” Cipolletta told NATURE. “Working in a conservation project is, for me, the ultimate fulfillment because it gives me the chance to contribute to their protection while having the opportunity to work directly with them.”

If you’ve been to a zoo, you’ve probably seen a lowland gorilla. Despite their ubiquity in captivity, in the wild, lowland gorillas have proven far harder to study than their better-known cousins, the mountain gorillas. Lowland gorillas are hard to approach and live in thick, brushy forests that make it difficult for researchers to follow the animals.

Working under the auspices of the World Wildlife Fund, Cipolletta went to the Dzanga-Sangha region to learn more about western lowland gorillas. Her work is part of a larger effort to protect the region, where conservation groups and the government have established a 1,250-square-mile system of protected lands. These areas are filled with dense tropical forests and small, wet clearings called bais which attract animals, including gorillas.

To gain the gorillas’ trust, Cipolletta asked for help from the BaAka (Bi-AK-uh), local tribes people who have an intimate understanding of the forest and an extraordinary ability to find their way around it. Although the BaAka sometimes hunt gorillas they are generally afraid to get near them. So Chloe’s idea of tracking and then trying to get close to them must have seemed like madness. But eventually the BaAka, including Nbanda and Ngombo, two of their best trackers, agreed to help her. She admits she could not have found the gorillas without them.

The idea was to get the gorillas habituated to people, thereby enabling researchers to more easily study the primates, and to turn the area into an ecotourism destination, which might benefit the local economy. Planners hope such tourism will create an incentive to preserve the ecosystem and make the BaAka allies in protecting the gorillas.

In Deep Jungle, viewers watch as Cipolletta and her colleagues pick up the trail of a male gorilla silverback and his son, eventually ending up face to face with the pair. It was a memorable moment years in the making, but things have changed since the film was made, Cipolletta explains.

“Mlima (the silverback in the film) succeeded in acquiring a female, and was in [his] best shape ever,” she wrote. “But that attracted the attention of a lone silverback who opposed him, and wanted to attract the female. They fought and Mlima died as a result of the wounds.”

“The juvenile featured in the film, Ndimbe, was wounded too but survived,” Cipolletta wrote. “It was dramatic, but we also know that Mlima had a few very happy weeks with his new female before dying.” Cipolletta says tourists are able to watch the Makumba group of gorillas, “a family of 13 individuals with many kids.”

There are also signs that the BaAka have gained a new perspective on gorillas. “I still get surprised about many things while working here, and that’s one of the things keeping me here,” Cipolletta says. “Certainly a most encouraging moment was after the death of the silverback. I received so many condolences from people in the villages. The way so many people responded surprised me a lot and gave me much hope.”

Can the secrets of our past be found in the jungle? And what can it tell us about our future?

Accompany researchers in NATURE’s Deep Jungle: The Beast Within as they explore tropical forests for clues about the origins of humans and what our own future might hold.

In a bid to understand the genesis of human aggression, primatologist David Watts travels to Uganda’s Kibale National Park to study chimpanzees. In the past, researchers had witnessed these primates hunting, killing, and eating colobus monkeys. Watts, however, made a chilling new discovery that these primates also hunted and murdered their own kind. The theory under investigation is that violence may help chimp groups cement social ties.

In Brazil, clever capuchin monkeys use heavy rocks to crack open nuts for food. “Deep Jungle: The Beast Within” marks the first time the behavior has been captured on film. Tool use, which was previously thought to be a skill only of primates — humans and chimps — reminds us that human abilities arose long before the evolution of our species.

In Central America and Cambodia, archaeologists ponder the ruined remains of ancient cities that once flourished in the jungle. What might have happened to these lost civilizations? And can modern cities avoid the fate that befell those that came before?

In the Central African Republic, primatologist Chloe Cipolletta enlists the help of the BaAka people in her effort to preserve the jungle’s future. The BaAka have lived in the forest for generations, and are experts at tracking the elusive western lowland gorilla. Together, Chloe and the BaAka are gaining the gorilla’s trust and in return, the BaAka are learning to see the gorillas as more than a threat.

To order a copy of Deep Jungle, please visit the NATURE Shop.

Online content for Deep Jungle was originally posted in May 2005.

Producer

RONNIE GODEANU

Art Director

SABINA DALEY

Designers

LENNY DROZNER

KAREN MATTSON

RADIK SHVARTS

Pagebuilding

BRIAN SANTALONE

Writer

CATHERINE DOLD

Production Artist

RUIYAN XU

Technical Director

BRIAN LEE

Content Consultant

GIANNA SAVOIE

Thirteen Online is a production of Thirteen/WNET New York’s Kravis Multimedia Education Center in New York City. Anthony Chapman, Director of Interactive & Broadband. Bob Adleman, Business Manager. Carmen DiRienzo, Vice President and Managing Director, Corporate Affairs.

Television Credits

Producers

JOHN WATERS

GIL DOMB

Photography

JOHN WATERS

GIL DOMB

BILL WALLAUER

Sound

BILL WALLAUER

Film Editor

DAVID DICKIE

Writer

ANNE MacLEOD

Dubbing Editor

KATE HOPKINS

Music

JENNIE MUSKETT

Post Production Manager

DOMINIC WESTON

Dubbing Mixer

RICHARD CROSBY

Videotape Editor

RICHARD KNAPMAN

Assistant Editor

NIKKI REEVES

Production Team

JANICE BEATTY

TINA CLARKE

SONJA GRIMES

WILLIAM MEEHAN

MBARAKA MKWEPO

BENJAMIN URASSA

Production Executive

BARBARA STOHLMAN

Scientific Consultant

CHARLOTTE UHLENBROEK

Archive Footage

HUGO van LAWICK

Special thanks to

TANZANIA NATIONAL PARKS

THE JANE GOODALL INSTITUTE

DR. ANTHONY COLLINS

PETER MSUYA

HILALI MATAMA AND THE GOMBE RESEARCH TEAM

Executive Producers

HUGO van LAWICK

MICHAEL ROSENBERG

For NATURE

Executive Producer

FRED KAUFMAN

Science Editor

JANET HESS

Coordinating Producer

JANICE YOUNG

Associate Producers

JESSICA SIEGEL

CAROLINE CORNEY

Researchers

SUSANE LEE

HILDY RUBIN

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JILL CLARKE

Production Secretary

KEVIN DOYLE

Manager

EILEEN FRAHER

Production Manager

JOHN SCHWALLY

Videotape Editors

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KURT ENGFEHR

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ED CAMPBELL

Host Sequence Directed by

FRED KAUFMAN

Filmed by

ALAN DEGEN

at

FERNBANK SCIENCE CENTER

Executive Editor

GEORGE PAGE

A co-production of

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This program was produced by Thirteen/WNET New York,

which is solely responsible for its content.

“Change alone is unchanging,” the ancient Greek philosopher Heraclitus once wrote. But even such a wise man didn’t know the half of it. As NATURE’s The Body Changers shows, researchers have discovered that all kinds of animals — from sea slugs and caterpillars to songbirds and people — undergo constant and often remarkable physical changes during their lives. And scientists continue to discover that we can change our bodies in ways once thought impossible.

A butterfly will emerge from this body changer.

Each of us knows from personal experience that the passage of time is marked by constant variation and modification. From a single cell unable to live on its own, we multiply into creatures composed of trillions of cells able to move about freely. Our bodies grow taller, heavier, and hairier as we mature, then shrink and wrinkle as we age. Our hair may change color and our voices modulate from a howling cry to a quivery whisper.

But even these dramatic physical alterations are overshadowed by the extraordinary transformations experienced by other creatures profiled in The Body Changers. Fleet-flying dragonflies, for instance, start life as swimming nymphs that paddle about beneath the surface of a pond or river. High-leaping frogs take their first trips as awkward, wriggling tadpoles. And the elegant, fragile butterfly emerges from a capsule spun by a chunky, crawling, earth-bound caterpillar.

Still other animals are able to execute even more amazing tricks. Salamanders can regrow legs snipped off by hungry turtles, while lizards routinely rebuild tails that break away, by design, in the mouths of predators. Male deer grow magnificent antlers that are used for just one season and then discarded, like a wedding dress banished to the back of the closet. And some songbirds remold their brains every spring, adding and subtracting neurons as needed. When more brainpower is needed to sing and remember their courtship songs, their brains swell. But when breeding season is over, they conserve energy by scaling back.

Such modern-day adaptations are the product of millions of years of evolution — another process dependent on change. Many researchers, for instance, believe today’s birds began as dinosaurs, while people evolved from tree-dwelling apes. Over the eons, seemingly insignificant changes began to add up, separating new species from the old. The genetic flaw that produced feathers on some mutant dinosaur, for instance, may have helped keep it warmer and enhanced its survival. Later, the feathers might have helped its offspring become better hunters and eventually fliers. It was just a short flap, in geologic time, to modern birds, which bear just a fleeting resemblance to their forebearers.

We’ll probably never know for sure just how all these changes took place, or why they occurred. It is difficult to follow the biological path that brought us here back into the mists of time. But researchers continue to make surprising new discoveries about our ability to change. For years, for instance, scientists believed that it was nearly impossible for humans and related apes to grow new brain cells. Conventional wisdom held that the most important parts of our brains were pretty much set by the age of three or four, and would grow no more.

Are brain cells continually added to all primate brains?

But in 1999, in a finding that eventually could lead to new methods for treating brain diseases and injuries, Princeton University scientists discovered that new brain cells are continually added to the brains of adult monkeys. Brain researchers Elizabeth Gould and Charles Gross found that the monkeys add neurons to several regions of the cerebral cortex that are crucial for memory, high-level decision making, and for recognizing and learning about the world. The results strongly imply that the same process occurs in humans, because monkeys and humans have similar brain structures. “If what they have shown holds true for all primates, including humans, it means we really need to rewrite the book on brain development and the way that experience can affect the brain,” says William T. Greenough, director of the neuroscience program at the University of Illinois’ Beckman Institute.

At the time of the discovery, Gross asked the question shared by many: “If the cerebral cortex is important in memory, how could it change?” He went on to explain, “In fact, the opposite view is at least as plausible: if memories are formed from experiences, these experiences must produce changes in the brain.”

Practical applications of the discovery could be years, even decades away. But the results suggest that scientists may one day exploit natural repair mechanisms to treat brain injuries or diseases, such as Alzheimer’s and Parkinson’s diseases. The discovery also may require scientists to draw a less bold distinction between the brains of humans and other animals, says Fernando Nottebohm of Rockefeller University, who has pioneered the study of changing bird brains. “What you can say now,” he says, “is that the primate brain is more like that of songbirds.” That, indeed, is a change in thinking.

Like other primates, orangutans exhibit humanlike qualities — from careful parenting to the use of tools. But how do their thought processes work? Are orangutans capable of cognitively figuring out complex problems? To find out, Washington DC’s National Zoo has set up the Think Tank, a research center where orangutans do everything from solve puzzles to operate computers — tasks usually left to scientists. Rob Shumaker coordinates the Think Tank’s Orangutan Language Project, featured on the NATURE program. There, he teaches orangutans a language based on symbols to find out how they think.

Once the orangutans have learned how the symbols work, scientists reason, the apes may start to put them in an order that signifies meaning.

Azy, an adult male, knows seven different symbols. Shumaker and his colleagues also investigate how well these apes resolve complicated problems, such as retrieving food from locked containers.

Azy and Indah, a female also featured on NATURE, must figure out the best way to get a delicious-smelling peach out from a box shut tight with a variety of clasps. After some initial pummeling, both orangutans stopped bashing the boxes and used their hands, feet, and prior experience to get the clasps open, reasoning out the solution the same way humans do.

That’s not surprising when you think about how closely related we really are. The only primate closer to us is the African ape. But as human as they seem, orangutans are actually wild animals perfectly suited to their forest environment. Weighing in at a hefty 200 pounds, an adult male orangutan is four times as strong as an adult male human and the largest animal to dwell in trees. When climbing on vines, orangutans’ flexible hip joints and hand-like feet make them seem to have four arms rather than two arms and two legs.

The natural home of the orangutan is the leafy canopy of the Southeast Asian rainforests in Sumatra and Borneo, which are abundant with the fruit that these apes eat. The growth of the logging industry in these areas has placed this habitat in grave danger, so many zoos have begun programs to increase the worldwide orangutan population.

Whether they live in treetops or zoos, orangutans exhibit a high level of intelligence. Orangutans in the wild are capable of creating and using tools; those in captivity demonstrate their ability to think and solve problems, like the puzzles at Washington DC’s National Zoo, featured in rangutans: Just Hangin’ On. It is no accident that the Malay name for this animal, “orang utan,” translates as “man of the forest.”

Online content for Orangutans: Just Hangin’ On was originally posted December 1997.

The Jane Goodall Institute
http://www.janegoodall.org
Includes basic biographical information on Jane Goodall and chimp-related links.

Discover Chimpanzees
http://www.discoverchimpanzees.org
The home page of the Jane Goodall Institute’s Center for Primate Studies.

Primate Image Collection
http://www.primate.wisc.edu/pin/images/chimps.html
Chimpanzee images from the Audiovisual Archive Wisconsin Regional Primate Research Center.

C.H.I.M.P.P. Homepage
http://jinrui.zool.kyoto-u.ac.jp/CHIMPP/CHIMPP.html
A paper on C.H.I.M.P.P., or Chemo-Ethology of Hominoid Interactions with Medicinal Plants and Parasites, discussing whether chimps intentionally eat medicinal plants when sick.

Chimpanzee Hunting Behavior and Human Evolution
http://www.amsci.org/amsci/articles/95articles/Stanford-full.html
A paper about chimp hunting habits that appeared in AMERICAN SCIENTIST.

Gombe Stream National Park Information
http://www.tanzania-web.com/parks/gombe.htm
Fact sheet on the park, including how to get there and what to expect.

Books

De Waal, Frans. CHIMPANZEE POLITICS: POWER AND SEX AMONG APES. Baltimore: Johns Hopkins University Press, 1989

Ferber, Elizabeth. JANE GOODALL: A LIFE WITH ANIMALS. London: Marshall Cavendish, 1997.

Fouts, Roger, and Stephen Tukel Mills. NEXT OF KIN: WHAT CHIMPANZEES HAVE TAUGHT ME ABOUT WHO WE ARE. New York: William Morrow, 1997.

Goodall, Jane. IN THE SHADOW OF MAN. New York: Houghton Mifflin, 1988.

Goodall, Jane. THROUGH A WINDOW: MY THIRTY YEARS WITH THE CHIMPANZEES OF GOMBE. New York: Houghton Mifflin, 1991.

Goodall, Jane and Alan Marks. WITH LOVE: TEN HEARTWARMING STORIES OF CHIMPANZEES IN THE WILD. New York: North South Books, 1998.

Goodall, Jane and Michael Neugebauer. THE CHIMPANZEE FAMILY BOOK. New York: North South Books, 1997.

Peterson, Dale and Jane Goodall. VISIONS OF CALIBAN: ON CHIMPANZEES AND PEOPLE. New York: Houghton Mifflin, 1994.

Pratt, Paul and Paula Bryant Pratt. THE IMPORTANCE OF JANE GOODALL. London: Lucent Books, 1997.