It's been more than 40 years since I first set foot on the sandy beach of what is now Tanzania's Gombe National Park. The steep, heavily forested valleys and cascading streams on the shores of Lake Tanganyika formed the backdrop for one of the most thrilling phases of my life. Though I was armed with little more than secretarial training and a passion for animals, paleontologist Louis Leakey gave me a mandate:
Get the wild chimpanzees to accept you, observe their behaviors, and describe what you see. The rest, thanks in no small part to the National Geographic Society, is well-documented history.
We knew so little about these secretive creatures back then that everything seemed like a revelation. What were once thought to be peaceful, simple vegetarians turned out to be powerful, highly intelligent hunters with complex personalities and emotions: beings capable of communication, altruism, political alliances, infanticide, warfare, and tool making—the last once thought to distinguish humans from the rest of the animal kingdom.
Unaware of the scientific prejudices of the day, I gave the chimps names and described their rich personalities in human terms, a practice that drew scalding condemnation from some scientists. I readily admit that I was fond of certain chimpanzees. And I believed that having a degree of empathy for my subjects could help me detect slight changes in their mood or attitudes and provide insights into their complex social processes. I think time has proved me right.
Though I stopped active field research in 1986 to focus on chimpanzee conservation, I left the Gombe Stream Research Center in the able hands of a new generation of scientists and dedicated Tanzanian field staff who now follow a new generation of chimps. It has become one of the longest continuous studies of an animal group in history. This body of work has spawned numerous research papers, doctoral theses, and books, providing insights not only into intricacies of chimpanzee behavior but into the lives of early humans as well.
Today I head to Gombe whenever I'm able to escape from a schedule that keeps me lecturing and traveling more than 300 days a year, spreading the word about the plight of chimpanzees in the wild and in captivity. I like to walk alone to an area called the Peak, close to where the chimpanzee I named David Greybeard first accepted me 43 years ago. He was the first individual I saw making a grass stem to fish termites out of their nest, an observation that prompted Leakey's famous remark: "Now we must redefine Man, redefine tool, or accept chimpanzees as humans." When David Greybeard died of pneumonia in 1968, I mourned for him as I have for no other chimpanzee.
Even after all these years, the vivid Gombe characters continue to surprise and delight us. Last October, Fifi, the only surviving chimpanzee I knew as an infant in the early 1960s, delivered her ninth offspring at age 44. Most females don't raise more than two or three offspring to reproductive maturity, but Fifi has four adult offspring, two healthy adolescents, a juvenile, and now a brand new infant. Her high rank allows her to control a particularly food-rich patch of habitat in the central Kakombe Valley, which contributes to her phenomenal breeding success. All but one of her offspring have survived, including Frodo, the current dominant male. At 121 pounds he is the second largest chimpanzee ever recorded at Gombe—and he rules with an iron fist.
Gremlin, one of my longtime favorites, is currently raising the third set of twins in the record books at Gombe. Survival for twins, who must compete for a limited supply of milk, is hard. But with Gremlin's patient nurturing, both Golden and Glitta, now four, are thriving. One of the best termite fishers in the community, Gremlin is also providing researchers an excellent opportunity to learn how such skills are passed down from generation to generation.
New technologies have facilitated exciting breakthroughs. By using DNA analysis of fecal samples, we can for the first time determine the paternity of many of the chimps, allowing us to examine the relationships between males and their offspring. We know that females avoid mating with their brothers and sons, but now we'll be able to learn whether an incest taboo exists between fathers and daughters as well.
Unfortunately, some of the news coming out of Gombe is distressing. Growing human pressures on the park threaten the chimpanzees' very existence. Unlike the vast swaths of forest that still surround chimpanzee populations in central Africa, Gombe National Park is only eight miles long and one to two miles wide, lying at the far eastern edge of the chimpanzees' natural range. When I arrived in 1960, the reserve was surrounded by large tracts of undisturbed forest that stretched to the east and south, with strips of forest to the north that linked the Gombe chimps to those in nearby Burundi. That habitat outside the park has all but vanished. New maps produced by Gombe researchers clearly show that it has become a 13.5-square-mile patch of forest surrounded by farms and denuded hillsides.
Though small villages have always existed in the area, the population density rose dramatically during the past decade, fueled by waves of refugees fleeing bloody civil wars in Burundi and the Democratic Republic of the Congo. The United Nations estimates that nearly a million have escaped from Burundi alone, with thousands settling in camps and villages in the Kigoma region around Gombe. The growing demand for wood, food, and charcoal has led to illegal logging and the snaring of wildlife within the park.
Yet it's the loss of the surrounding forest that poses the greatest threat. Gombe was once home to about 150 chimpanzees in three communities. Today, that number has dwindled to about a hundred. Although the main study group, known as the Kasakela community, has maintained its population of about 50 individuals, the northern and southern groups, which once foraged outside the park, are in decline. Only two or three adult males are left in the southern group. Unless we can enlarge existing habitat corridors linking the park to communities in the north, the Gombe chimpanzees could succumb to disease or inbreeding within decades.
It doesn't have to end that way. We have the good will of most of the people living near the park, which means the enlarged corridors may someday be a reality. Researchers have learned that if villagers leave the stumps on the bare hillsides rather than hacking at them for firewood, the miombo woodlands will regenerate within five years. Patches of resprouted trees now border the lakeshore. Conservation education and micro-loans to women who practice sustainable farming are beginning to have an impact.
Perhaps the most important thing we've learned at Gombe is how similar we are to these creatures, with whom we share between 95 and 98 percent of our DNA. As we watch their numbers dwindle and their forests fall, their legacy becomes as clear as a Gombe stream: As they go, so, one day, may we.