Last year brought good news for great apes when Wildlife Conservation Society (WCS) researchers discovered a motherlode of more than 125,000 gorillas in a large swamp in the Republic of Congo. But now, that secretive population is coming under increasing threats as humans move into the region.

Recent surveys confirmed that high densities of the great apes still exist in the remote location, and WCS is urging that their home in the swamp forests adjacent to the southwest border of Lac Télé Community Reserve be protected.

The findings and recommendations appear in the November issue of the journal Oryx. The study was authored by WCS conservationists Hugo Rainey, Emma Stokes, Fiona Maisels, Samantha Strindberg, Fortuné Iyenguet, Guy-Aimé Malanda, and Bola Madzoké. Domingos Dos Santos from the Republic of Congo Minstère de l’Economie Forestière was also a co-author.

In addition to the gorillas, the swamp supports large numbers of chimpanzees, red colobus monkeys, and elephants. Imminent threats to their habitat include new logging operations, oil exploration, and an influx of refugees from neighboring Democratic Republic of Congo. As a result of all these developments, the local human population has grown, new roads have spread through the forest, and the illegal bushmeat trade has escalated.

“We implore both the government of the Republic of Congo and the international community to begin the groundwork for the creation of a new protected area to safeguard these gorillas and their unique environment for the benefit of future generations,” said Dr. James Deutsch, WCS-Africa director. “Losing gorillas in this region after all the attention from their discovery would be a sad coda on an otherwise great story.”

The researchers conducted the latest surveys by counting the leafy sleeping nests the gorillas built each night. From this data, they calculated that the 379-square-mile study area contained an estimated 5,042 gorillas, more in fact than previous estimates for the site. The result is one of the highest density estimates ever calculated for gorillas—more than 13 gorillas per square mile.

Funders for the surveys and project include the U.S. Fish & Wildlife Service and the USAID-Central Africa Regional Program for the Environment (CARPE).