Photo by mattiasklumofficial / I photographed this playful mountain gorilla in Volcanoes National Park, Rwanda. Do you know why some gorillas have black teeth and tongues? Well, the tannins in the plants gorillas eat are responsible for turning their teeth and tongues black. We humans have the same problem, but to a lesser degree, with staining from tannins in tea, wine, etc. We don't eat or consume the degree that gorillas would, as they need to eat a considerable amount of vegetation to meet their nutritional requirements and maintain body mass. By protecting mountain gorillas we ensure beautiful and resilient forests and livelihoods for local people too. Please go to mattiasklumofficial to see more mountain gorillas and other remarkable places and creatures from around the world. #mattiasklum #protectbiodiversity #virunga #rwanda #gorilla thephotosociety