Researchers in the 1980s had estimated that fewer than 100,000 western lowland gorillas were in existence. Until now, many experts believed that the population had since fallen by at least half, due to disease and hunting.
"We have found the mother lode of western lowland gorillas," Steven Sanderson, president of the Wildlife Conservation Society, which led the research, told National Public Radio. "We had no idea that these great densities [of the gorillas] were possible in central Congo."
Researchers estimated the numbers of gorilla by counting their nests, because the reclusive animals are too difficult to count directly.
Gorillas in other parts of central Africa have long been threatened by wars, logging that destroys their habitats, commercial poaching and disease outbreaks, including the Ebola virus.
But the remote area in which they were found, an 18,000-square-mile swath of forests and swamps nicknamed the "green abyss," has remained largely untouched and unstudied by gorilla researchers.
"We call it the 'green abyss' because [...] you go into it, and it's a world unto itself," U.S. Fish and Wildlife Service researcher Richard Ruggiero, who was not involved in this research but has studied gorillas in central Africa for 15 years, told NPR. "These swamp environments are extremely difficult to get along in, there's literally no place to pitch a tent and sleep."
The forces that have kept loggers, poachers and other humans out have protected the gorillas until now, Ruggiero said, but that could change. Recently the government has begun to sell logging rights in parts of the forest.
"It's horrific, frankly," he said. "And the value of this announcement of this large population is, hopefully, people will realize that this is a chance to get there before the [hunters and timber companies] do."
The government of the Republic of Congo has recently made one of the studied regions, Ntokou-Pikounda, which is estimated to hold 73,000 gorillas, into a national park. However, there is little money for staff or operations there, conservation society officials told the New York Times.
Still, Sanderson told the paper, the situation for gorillas in the region looks promising. "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 WCS released its findings Tuesday at a meeting of the International Primatological Society Congress in Edinburgh, Scotland.
