Trove of Endangered Gorillas Found in Africa

[Janilee Wolff]

Trove of Endangered Gorillas Found in Africa
By ANDREW C. REVKIN
Published: August 5, 2008

A grueling survey of vast tracts of forest and swamp in the northern Congo Republic has revealed the presence of more than 125,000 western lowland gorillas, a rare example of abundance in a world of rapidly vanishing primate populations.

As recently as last year, this subspecies of the world’s largest primate was listed as critically endangered by international wildlife organizations because known populations — estimated at less than 100,000 in the 1980s — had been devastated by hunting and outbreaks of Ebola virus. The three other subspecies are either critically endangered or endangered.

The survey was conducted by the Wildlife Conservation Society and local researchers in largely unstudied terrain, including a swampy region nicknamed the “green abyss” by the first biologists to cross it. Dr. Steven E. Sanderson, the president of the society, marveled at the scope of what the survey revealed. “The message from our community is so often one of despair,” he said. “While we don’t want to relax our concern, it’s just great to discover that these animals are doing well.”

The society is to release its findings on Tuesday at a meeting of the International Primatological Society in Edinburgh. Conservation society scientists said the continuing threat of Ebola precluded a change in the gorilla’s status. But the discovery was mainly stirring excitement.

“This is the light of hope you look for,” said Richard G. Ruggerio, a conservation biologist at the United States Fish and Wildlife Service. But he cautioned that the large gorilla populations in the two studied tracts, which cover 18,000 square miles, should not lead to complacency. “It’s a different kind of alarm call, an opportunity that is increasingly rare on this planet — to do something before there’s a crisis,” he said. A separate global update on primates is being issued Tuesday at the Edinburgh meeting, showing that — with a few exceptions — forest destruction and, increasingly, hunting for meat, pets and Chinese medicinal products are imperiling monkeys and other primates, from Congo Republic to Cambodia.

In Vietnam and Cambodia, 90 percent of primates — including gibbons, leaf monkeys and langurs — are considered at risk, said scientists affiliated with the International Union for Conservation of Nature, which issued the update with Conservation International.

“What is happening in Southeast Asia is terrifying,” said Jean-Christophe Vié, deputy chief of the group’s species program. “To have a group of animals under such a high level of threat is, quite frankly, unlike anything we have recorded among any other group.”

The lowland gorillas discovered in the Congo Republic survey are secure for now, but pressures are growing on wildlife in central Africa as international demand builds for tropical hardwood and other resources. The government of Congo Republic has granted national park status to one of the studied regions, Ntokou-Pikounda, which is estimated to hold 73,000 gorillas. But there is little money for staff or operations, conservation society officials said.

Over all, Dr. Sanderson said, the situation for the surveyed gorillas in Congo Republic appears promising. Along with the park plans, some logging companies that sell lumber certified as responsibly harvested are working with the conservation society and the government to adjust practices in ways that preserve habitat and limit meat hunting.

[Janilee Wolff]

The western lowland gorilla subspecies was listed by wildlife organizations as critically endangered because known populations had been devastated by hunting and outbreaks of Ebola.
Photo: Dave Morgan/Wildlife Conservation Society

[Janilee Wolff]

The Wildlife Conservation Society and local researchers in Congo surveyed hard-to-reach areas covering 18,000 square miles that had been largely unstudied. The new census revealed 125,000 western lowland gorillas in these areas. The remoteness and inaccessibility of many of the survey locations may be part of the reason that such high numbers of gorillas went undetected for so long.
Photo: Wildlife Conservation Society

[Janilee Wolff]

Many western lowland gorillas gather to feed and interact in forest clearings called bais. In the bais, researchers are able to observe the gorillas and gather data on group dynamics.
Photo: Thomas Breuer/Wildlife Conservation Society-Max Planck Institute for Evolutionary Anthropology.

[Janilee Wolff]

A baby western lowland gorilla waving from the back of its mother. Female gorillas produce on the average one baby in intervals of about five years.
Photo: Thomas Breuer/Wildlife Conservation Society-Max Planck Institute for Evolutionary Anthropology.

[Janilee Wolff]

Photo: Thomas Breuer/Wildlife Conservation Society-Max Planck Institute for Evolutionary Anthropology

[Janilee Wolff]

A family group of western lowland gorillas usually consists of a single large male -- the silverback -- a few adult females and several babies and youngsters.
Photo: Thomas Breuer/Wildlife Conservation Society-Max Planck Institute for Evolutionary Anthropology.

[Janilee Wolff]

A group of group of gorillas watching a sitatunga, a type of antelope that lives in the swamps of central Africa.
Photo: Thomas Breuer/Wildlife Conservation Society-Max Planck Institute for Evolutionary Anthropology

[Janilee Wolff]

While the new census provided good news about the gorillas, a separate report by the International Union for Conservation of Nature and Conservation International provided a gloomy status on many other species of primates. In Vietnam and Cambodia, 90 percent of primate species, including the tonkin snub-nosed monkey, are in danger of extinction.
Photo: Tilo Nadler

[Janilee Wolff]

A success story: the golden lion tamarin in Brazil was downlisted from critically endangered to endangered in 2003, after three decades of conservation efforts.
Photo: Haroldo Castro/Conservation International

[Janilee Wolff]

In Africa, 11 of the 13 kinds of red colobus monkeys assessed were listed by the report as critically endangered or endangered. Here, a Kirk's red colobus sits in a tree in Tanzania. Two species of red colobus may already be extinct. The Bouvier's red colobus has not been seen in 25 years, and while there are occasional reports of the Miss Waldron's red colobus, no primatologist has seen one since 1978.
Photo: Tom Struhsaker

[Janilee Wolff]

The javan, or silvery gibbon, in Indonesia remains critically endangered. The cutting of forests has greatly reduced the habitat for many primates. Many are also hunted for food and Chinese traditional medicine.
Photo: Sunarto/Conservation International