W.Africa gorillas still endangered, declining fast

Gorillas and chimpanzees may be twice as numerous in West Africa as previously thought, but the apes are still endangered, declining fast and in dire need of protection, an international study found Wednesday.

Prior estimates were based on nest counts taken from isolated areas across the great apes’ habitat range, said the report in the journal Science Advances.

The new count uses mathematical modeling to project likely ape numbers in areas where their nests haven’t been directly surveyed by people.

The estimates are based on other factors known to influence ape numbers, such as proximity to roads and people, and recent outbreaks of Ebola virus which can be deadly.

Spanning 59 sites in five countries surveyed over 11 years, it is the most comprehensive and accurate dataset ever compiled on these apes, said one of the lead authors, Fiona Maisels, conservation scientist for the Wildlife Conservation Society.

The results show that western lowland gorillas in western equatorial Africa number nearly 362,000, up from prior estimates of 150,000-250,000 individuals.

And chimpanzees in the area are expected to number almost 129,000, up from earlier counts of 70,000 to 117,000.

But despite the larger numbers, researchers still found a speedy drop in the population in recent years, which means the apes are still in danger of going extinct.

Some 19.4 percent of the gorilla population was lost between 2005 and 2013, said the report.