There are far more gorillas and chimpanzees hiding in the dense and impenetrable rainforest of central Africa then anyone thought, unfortunately, most of these are to be found living outside of protected areas and are still facing considerable threats.

That is the main conclusion of the largest ever survey of western lowland gorillas and central chimpanzees published this week in Science Advances. While it is undeniably good news that there are at least a third more gorillas and a tenth more chimpanzees living in the remote corners of Africa's forests, this has been tainted by the fact that the apes are still at a significant risk of “guns, germs, and [felled] trees”.

It is now thought that there are some 360,000 western lowland gorillas (Gorilla gorilla gorilla) – which account for 99 percent of all gorillas – roaming the rainforests along with 130,000 central chimpanzees (Pan troglodytes troglodytes). While this sounds like a vast number of apes, the study found that the number of gorillas has crashed by over 20 percent in the last eight years alone meaning that they are still considered critically endangered, and the chimpanzees are still endangered.

“It's great news that the forests of Western Equatorial Africa still contain hundreds of thousands of gorillas and chimpanzees, but we're also concerned that so many of these primates are outside of protected areas and vulnerable to poachers, disease, and habitat degradation and loss,” explained lead author Samantha Strindberg, of the Wildlife Conservation Society, in a statement.

The study was a massive undertaking, collating a decade’s worth of data from 8,700-kilometers-worth (5,400 miles) of surveys across five central African nations, including Equatorial Guinea, Cameroon, Gabon, the Republic of Congo, and the Central African Republic. They included more refined surveying methods in order to gain more accurate numbers, as well as areas previously missed such as remote inaccessible forests, tracts between survey sites, and regions outside of protected areas.

The vast majority of the new apes discovered – around 80 percent – were found to be living outside of any protected areas, which is of real concern to the team behind the research. It shows that they are likely under immense pressure from hunting for bushmeat, felling of their forests for agriculture and timber, as well as the very real worry of Ebola outbreaks sweeping through the populations.

“These findings can help inform national and regional management strategies that safeguard the remaining habitat, increase anti-poaching efforts, and curtail the effects of development on great apes and other wildlife,” Strindberg continued.

The researchers are warning that the new higher numbers cannot be taken for granted and that with the correct planning and management of competing interests, their numbers could one day be doubled, securing their future just for a little bit longer.