Mountain gorillas have been raised from the list of "endangered species" after a rare and surprising increase in their numbers over the past 10 years.
A survey this year found that the number jumped to 1,000 from 680 in 2008, prompting scientists to transfer it to the list of "endangered species".
"Although the mountain gorilla numbers are very good news, the strain is still threatened and conservation efforts should continue," said Liz Williamson, an expert at the International Union for the Conservation of Nature.
The famous gorilla, with its silver back, attracts thousands of tourists who pay hundreds of dollars to see it.
Gorillas live in the volcanic region, which is covered by forests outside the West Africa rift, where the borders of Rwanda, the Congo and Uganda meet. Their natural habitats contain strains that are nowhere else, including the golden monkeys, endangered by fishers, political unrest and disease, including the Ebola virus.
"The biggest threat to mountain gorillas will be the emergence of a new highly contagious disease because it will be very difficult to control," said Williamson.
