New research on mountain gorilla DNA

A study by some of the world’s leading mountain gorilla experts – including from the FFI-supported International Gorilla Conservation Programme – has shed new light on the number of mountain gorillas surviving in Uganda’s Bwindi Impenetrable Forest.

Gorillas are traditionally counted by proxy through nest counting. However, the scientists discovered that individual gorillas sometimes made more than one nest, leading to overestimation of the total number of gorillas in the population. It was also sometimes difficult for field teams to distinguish between adjacent gorilla groups or individuals based on tracks and nests.

By analyzing the mountain gorilla’s DNA, they were able to count the gorillas more accurately than ever before. The estimate of individuals in the park has reduced from 336 to roughly 300, thanks to genetic information.

Though the population at Bwindi Impenetrable Forest may be smaller than previously thought, there is no reason to believe it is not stable or increasing as previously thought. No doubt future counts will include molecular techniques to increase the precision of the population figures.

Bruce Liggitt, FFI’s International Gorilla Conservation Programme representative said:

‘Bwindi has not received the name ‘Impenetrable’ for nothing! Counting wildlife populations is always a challenge, but the rugged terrain and dense tropical forest at Bwindi makes it particularly difficult to monitor mountain gorilla populations.

I welcome the new findings that allow us to use genetic technology to give fresh insight into the gorilla numbers in Bwindi. With possibly even fewer mountain gorillas than previously thought, it is even more important that we strengthen our efforts to conserve these magnificent creatures.”