Terborgh: his quest is to preserve and conserve. Jim Wallace.
Terborgh: his quest is to preserve and conserve. Jim Wallace.

Identifying the Forests' Prime Evil

For nearly four decades, this environmental scientist has combed varied tropical settings to study birds, primates, herbs, trees, and their interactions. Through research, advocacy, teaching, and writing, he has sought to understand and protect what is left of the natural world.
January 31, 2002


Just to reach his longtime biological Shangri-la, John Terborgh must travel for days in a motor-driven dugout canoe. He describes the remarkable site in his 1999 book Requiem for Nature: "To my left, a towering forest looms over my lakeside office, its edge a tapestry of vines and branches that offer thoroughfare to throngs of monkeys. Long accustomed to the benign presence of humans in their midst, they parade before my view, hardly more than an arm's reach away on the other side of the screening."

For more than a quarter-century, Terborgh, James B. Duke Professor of Environmental Science at Duke's Nicholas School of the Environment and Earth Sciences, has been coming to this strikingly pristine place, the Cocha Cashu Biological Station within Peru's Manu National Park. He returns each year because the huge park contains more biodiversity than any other on Earth. Encompassing the watershed of the Manu River from the 13,000-foot heights of the eastern Andes Mountains to the Amazon jungle lowlands below, the park boasts more than 200 species of mammals, almost 1,000 different kinds of birds, and up to 200 different tree types per each 2.4 acres.

Terborgh believes that places like Manu are crucial for preserving this biodiversity, defined as the variety of plant and animal species still living on the planet. Conserving biodiversity, he writes starkly, means "establishing conditions that will serve to minimize future extinctions." His elegaic Requiem for Nature (Island Press) is not so much a celebration of nature and an exceptional park as it is a tale of developing tragedy.

Throughout a professional career that began in 1963, he has combed various tropical settings like this one--because most of the planet's plants and animals live there--to study birds, primates, herbs, trees, and the interactions among them. Through his research, his advocacy, and his often lyrical writing, he has sought both to understand and protect what is left of the natural world. In the process, he has also had to bear repeated witness to the general destructiveness of humans.

Earthmoving machines seem to have dogged his every step--an inevitable symptom, he says, of the inexorable pressures of too many humans seeking work and a better life. Too many times, the result is the destruction of forests and grasslands and the pollution of streams and waterways. Such destruction can be the result of primitive slash-and-burn agriculture as well as advanced corporate farming, road building, and development.

In country after country, Terborgh has also borne witness to what he calls inadequate government efforts to create sanctuaries for the nature that remains. He dismisses many of the results as "paper parks." He has started a monitoring program, with so-far inadequate funding, to improve some of these places.

At age sixty-five, this MacArthur Fellowship winner and National Academy of Sciences member, who also co-directs Duke's Center for Tropical Conservation, remains as engaged in battles to fund his conservation efforts as he is to produce scientific papers that challenge the conventional wisdom. He also continues to turn out books. His next one, Making Parks Work, will be, he says, uncharacteristically optimistic about the prospects for nature reserves.

Nature out of whack: one of the smaller islands' landscape of defoliated trees

Nature out of whack: one of the smaller islands' landscape of defoliated trees from ecological imbalance of leafcutter ants and howler monkeys. courtesy of Brad Balukjian.

Born in Washington, D.C., Terborgh was raised in a version of Arlington, Virginia, that no longer exists. "I remember when it was mostly farms," he says. "The farm scene in Arlington disappeared between 1946 and '48." Before that green bubble burst, "my whole formative period was devoted to biology. Its attraction just pulled me in, a fascination for nature, organisms, and natural places."

By age five he was already studying snakes. Then he took up bird watching and plant collecting. His early career choice, he says, had much to do with "being able to walk out my back door and walk all the way to the Potomac River without passing another house."

In Requiem, he describes what happened to Arlington during the post-World War II building boom. "Seemingly overnight, the forests vanished. Broad red scars in the Earth, the future streets and lanes of middle-class suburbs, bespoke the agony of the land. For me, the experience was shattering."

Nevertheless, Terborgh recovered from the sad plight of his hometown and kept going. In 1958, he received a bachelor's degree in biology with honors from Harvard. He followed that in 1963 with a Ph.D. in plant physiology.

As he noted in another of his books, Diversity and the Tropical Rain Forest (Scientific American Library, 1992), he was first drawn to tropical ecology just after earning his doctorate when he and a colleague made a "celebratory expedition" to South America. What continues to draw him back to the jungle year after year? "If I had to choose one word, it would be peace," he writes. "Being daily witness to the endless cycle of life and death brings a reassuring sense of symmetry and continuity. The lives of the plants and animals that share the forest are inextricably linked in a web of interactions--a web held together by a system of checks and balances that we are only beginning to understand."

Terborgh not only went on expeditions. From the beginning, he also taught the next generation of biologists and conservationists. For five years, he was an assistant professor of botany at the University of Maryland before moving to Princeton, where he eventually became the Class of 1877 Professor of Biology. In 1989, he moved to Duke as the Ruth F. DeVarney Professor of Environmental Science.

In 1991, he became a James B. Duke Professor of Environmental Science. The next year he received a $335,000 MacArthur Fellowship, popularly known as a "genius grant." Nobel Prize-winning physicist Murray Gell-Mann of Caltech broke the news to him. The John D. and Catherine T. MacArthur Foundation announcement noted that he would use the money in an on-foot "vegetation mapping" survey in Manu National Park and another Peruvian site.

Terborgh wrote in Requiem that he "discovered" the Manu park in 1973 after having to flee "the most beautiful place I had ever seen," Peru's Apurímac Valley. He was chased out of that valley after a road-building project funded by the U.S. program Alliance for Progress (implemented during the Kennedy administration) had paved the way for waves of human invaders, who chopped down trees and fomented illicit cocaine production and trafficking. Since that year, he has directed Manu's Cocha Cashu Biological Station under the auspices of the Peruvian government, supporting it with fees charged to the investigators who use the site.

According to the station's website, its role is "to provide a base within a large region of virgin forest from which to study all aspects of the ecology of lowland tropical forests." One major research emphasis is the variety of large resident vertebrates "that tend to be reduced or extirpated at other neotropical research sites," the website notes. Examples include jaguars, pumas, and harpy eagles, species that have been hunted out or eliminated by forest fragmentation at less remote reserves.

Terborgh: his quest is to preserve and conserve

Shangri-La: Terborgh's favorite place, Peru's Manu National Park, which has more biodiveristy than any other on Earth. Jeffrey Homer/CORBIS.

Cocha Cashu can accommodate nearly forty people at a time in primitive facilities that include a kitchen with two kerosene stoves (but no refrigerator) and a small library. Communication is by satellite phone and two-way radio, and there is an office with desks and shelves. There is no dormitory, so users must sleep in tents. They also traditionally bathe at the nearby lakeshore, though two showers were recently added.

"It is one of the most beautiful forests I have ever been in," recalls Jennifer Powers Ph.D. '01, whose doctorate in biology was accompanied by a certificate in ecology. Powers visited Cocha Cashu last fall as part of an advanced field course sponsored by the Duke-headquartered Organization for Tropical Studies.

While that course included visits to four tropical Latin American sanctuaries, "I think Cocha Cashu has, by far, the most spectacular trees," she says. "It's so remote that they have the full complement of animals. At night, even, you'd zip the door to your tent and hear the forest around you. All these insects, all the birds moving around, the monkeys--it just felt like the forest was alive."

Powers, who studied for her doctorate under Nicholas School Dean William Schlesinger, is equally enthusiastic about working with Terborgh. "Just being in the field with him was so exciting because he has worked in that forest for decades and he knows all the stories there," she says. "We took a couple of walks that he led and every five feet we were stopping. It took hours to get 500 meters down the trail because he knows all the plants, and he knows all the animals. He's an incredible naturalist. But then he also is one of the major players in terms of thinking about ecological theory in tropical systems."

Terborgh's early work at Manu was with the twelve species of primates that live there. "We made a lot of progress in trying to understand the variation in primate social systems that one sees in nature," he says. He is still co-authoring scientific papers on the tree surveys done with colleagues at Manu and other South American tropical forests.

His findings reported in one such article, published in 2001 in the journal Ecology, "challenge popular depictions of Amazonian vegetation as a small-scale mosaic of unpredictable composition and structure." These surveys instead "provide additional evidence that tropical tree communities are not quantitatively different from their temperate counterparts where a few common species...can dominate immense areas of forest."

Other research at Manu has documented the vital role that top meat-eating predators like jaguars play in preserving the jungle ecosystem. He and fellow scientists found that an absence of such hunting animals can allow overpopulations of seed-eating animals, which in turn suppress the forest's principal tree species.

"I've been harping on that theme for more than twenty years," Terborgh says of the importance of predation--an argument he and ten other scientists expounded in an article in the November 30 issue of the journal Science. Field work for that Science paper was not done in Peru but at a research site Terborgh directs in Venezuela with National Science Foundation funding. There, a non-natural lake called Lago Guri, encompassing an area almost the size of Connecticut, was created by a hydroelectric dam. In the process, many former hilltops became islands that isolated a variety of plants and animals.

Because Lago Guri's smaller islands contain no meat-eaters, they provided a good test for a controversy long raging in the ecological community, whether "top-down" or "bottom-up" drives natural systems. Proponents of the top-down view hold that predators play the key role in perpetuating plant and animal diversity in nature. The opposing bottom-up scenario argues that such biodiversity is driven by the variety of available consumable plants, because that determines the mix of plant eaters that then serve as food sources for predators.

The Science article, for which Terborgh was senior author, provides support for the top-down view. With no predators present, the investigators found strikingly "hyperabundant" numbers of plant eaters ranging from howler monkeys to iguanas, rodents, and leaf-cutter ants. In response, trees were dying off at accelerated rates, and many of the young plants were being consumed before they could grow.

Terborgh notes that the same process is under way in the humid eastern woodlands and arid grasslands of the United States. With the virtual elimination of former predators like wolves, Terborgh says the eastern regions now carry excess numbers of white-tailed deer, beavers, raccoons, and possums. In the west, he says, the culprits are livestock like cattle, horses, and sheep, and over-permissive government grazing policies.

In another book, Where Have All The Birds Gone? (Princeton University Press, 1989) and in a Scientific American article "Why American Songbirds Are Vanishing" (May 1992), he probed losses in migratory-bird populations that are causing quieter spring seasons in the United States. Just as in the tropics, a major cause here seems to be human destruction of habitats.

Since 1963, Terborgh has made annual field excursions to tropical sites as widespread as New Guinea, Madagascar, Cameroon, and Gabon, as well as to various Latin American sites. As he has studied the biology of all these places, he has also become an acute observer of what human societies are doing to nature. One chapter in Requiem, "Parks: The Last Bastions of Nature," describes most purported natural refuges in the tropics as "a sorry lot."

A majority of parks "exist only on paper," he writes, "having no staff whatsoever." Most are "poorly designed," and a "great many" have people living within them. "Some no longer exist in a biological sense." Terborgh describes his shocking visit to one Peruvian "paper park." Though it had technically been in existence for a decade, he and a companion learned they were its first visitors. He labels another park in Kenya, within sight of Nairobi's skyline, a "glorified game ranch."

Even 3.7-million-acre Manu, which he considers an exception, has had its share of problems. While strongly supported politically and administratively when it began in 1973, the park declined as economic problems, which have since improved, overtook Peru. During the darkest days, he wrote in Requiem, supply boats for park guards failed to appear, as did their pay and fuel, leaving Manu's guardians "obliged to hunt and fish to feed themselves."

Meanwhile, there could be a looming people problem caused by Manu's indigenous inhabitants, some of whom remain isolated from outsiders. Terborgh says he wonders what will happen as more natives exchange stone-age tools for guns and chainsaws, and begin seeking jobs to pay for more creature comforts--let alone educations for their children.

Terborgh's own funding has also seen hard times. In 1996, the year he received the National Academy of Sciences' Daniel Giraud Elliot Medal for meritorious work in zoology, his Center for Tropical Conservation was near to closing down after losing what was then its main financial support from the U.S. Agency for International Development. This loss came at the same time Terborgh, through his center, was just beginning to start ParksWatch as a watchdog organization seeking partnerships with local conservation groups in various sanctuaries in order to improve conditions there.

While the center and ParksWatch have both since scraped through (ParksWatch now has active projects in Venezuela, Peru, and Guatemala and is starting new ones in Mexico and Brazil), the financial futures of both remain uncertain. Yet Terborgh sounded surprisingly upbeat during his latest interview, held at his center's spartan offices near the Duke Primate Center.

That positive outlook is reflected in the new book he is helping edit, Making Parks Work: Strategies for Preserving Tropical Nature, in which "we try to see the bright side of the picture." Set for late-winter publication by Island Press, the new book is a sequel to Last Stand, National Parks, and the Defense of Tropical Biodiversity (Oxford University Press, 1997), in which he and eleven other authors (several from Duke) stressed the problems.

"In a relatively short span of time, just four or five years, there have been a lot of changes," he says. "There's more money going into conservation both from formal sources like the World Bank and other big development banks and from private sources as well."

He holds great hopes for one in particular, the Gordon and Betty Moore Foundation, which will draw on a multibillion-dollar contribution from the co-founder of computer chip maker Intel Corporation and his wife. One of that foundation's four program areas will be dedicated to biodiversity conservation, Terborgh says. "New mechanisms are coming in line for management of parks through non-governmental organizations and international organizations. Governments are getting more broad-minded about allowing and encouraging international participation in management of wildlands and protected areas."

While "the official U.S. government has been dragging its feet on all kinds of green issues for a long time," he says, pointedly, "much of the rest of the world is realizing that we're over-exploiting the Earth's resources."

"Conserving biodiversity is the responsibility of the generation that's alive and active right now to think about its future," he insists, "and not to turn over a destroyed world to the next generation."

Basgall is senior science writer in Duke's Office of Research Communications.