In a discovery almost unheard of in this day of satellite tracking, international communications and electronic surveillance, 125,000 western lowland gorillas were found this summer deep in the interior forests of the Republic of the Congo in Africa – a rare example of abundance in a world of rapidly vanishing animal populations and species.

The findings, if confirmed, would more than double the world’s estimated population of gorillas. Previous estimates from the 1980s had put their total population at less than 100,000. But that estimate is thought to have fallen as much as 50 percent because of illegal hunting and outbreaks of the Ebola virus. These new numbers would raise the estimated population in the wild to 175,000 to 225,000.

Western lowland gorillas are one of five gorilla subspecies and are classified as critically endangered by the International Union for Conservation of Nature (IUCN). All of the five species are classified as either endangered or critically endangered.

“This is the highest-known density of gorillas that’s ever been found,” said Hugo Rainey, one of the researchers who conducted the population survey for the Wildlife Conservation Society (WCS).

Acting on a tip from hunters who had seen the gorillas, the researchers who found the new groups trekked on foot for three days to the outskirts of Lac Tele, about 50 miles from the nearest road.

“We knew there were apes there; we just had no idea how many,” said Emma Stokes of the WCS and one of the lead researchers in a two-year census project.

Stokes added that the gorillas have likely thrived due to their remoteness from human settlements, food-rich habitats and two decades of conservation efforts.

Lowland gorillas, like those seen at the N.C. Zoo, are more common than their cousins, the mountain gorillas. Besides these new ones found in the Republic of the Congo, they’re found in the tropical forests of Angola, Cameroon, the Central African Republic, the Democratic Republic of the Congo, Equatorial Guinea and Gabon.

The WCS findings demonstrate that our planet still has its biological secrets. “It is extraordinary that in this day and age, there could be a population of a hundred thousand or more gorillas that were essentially unknown to science,” said Richard Bergl, curator of research at the N.C. Zoo.

Gorillas have a range of about 7.5 square miles and build their sleeping nests each night before moving on in the morning. Researchers made their estimates of the new gorilla populations by counting these sleeping nests. Gorillas tend to be too reclusive and shy to allow researchers to count them individually.

The gorillas were found 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 WCS, marveled at the numbers of the new gorillas. “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.”

While calling the discovery important, researchers add that the find does not mean that gorillas in the wild are now safe. Primatologists warn that as many as half of the world’s 634 known types of primates are in danger of becoming extinct due to human activities such as bush-meat hunting, habitat loss (forest destruction) and the use of animal parts in many folk medicines.

This discovery of new gorillas indicates that their population remains stable in some areas, but according to Rainey, it is likely that gorillas will remain critically endangered because of the continuing threats facing the species.

Overall, pressures continue to grow on wildlife in central Africa as international demand grows for the area’s natural resources. The government of the Congo Republic has granted national park status to one of the studied regions (with about 73,000 gorillas), but there is little money for staff or operations, ICUN officials said. Researchers hope that the find will spur global action to defend mankind’s nearest relative.

N.C. Zoo visitors can daily see the park’s four western lowland gorillas – one male and three females – at the Forest Edge exhibit in the Africa Region.



Tom Gillespie lives in Trinity and is a journalist and public affairs specialist at the North Carolina Zoo. For more information on the zoo’s plant and animal collections, special events and education programs, go to their Web site at www.nczoo.org