Poaching is the biggest killer of mountain gorillas, says New Scientist News, but respiratory diseases come a close second, accounting for about a quarter of deaths, according to a major survey.
Around 700 mountain gorillas live in two separate populations, one in Uganda and the other in a region that straddles Rwanda, the Democratic Republic of the Congo and Uganda. The animals are classed as critically endangered on the IUCN’s red list, although they are the only great ape species whose numbers are increasing.
The Mountain Gorilla Veterinary Project, based in Ruhengeri, Rwanda, investigated 100 gorilla deaths dating back to 1968. The team found that 40 were due to trauma, for which poaching is almost always the cause in adults. More surprising was the detrimental effect of respiratory diseases, including influenza A and parainfluenza viruses, which killed 24 of the animals.
In a bid to cut the risk of people passing these diseases on, eco-tourists who trek to see the gorillas in the wild already have to stay at least 7 metres away, and keep their visits to no more than an hour.