" When a silverback gorilla dies of Ebola, he does it beyond the eyes of science and medicine. No one is there in the forest to observe the course of his agony, with the possible exception of other gorillas. No one takes his temperature or peers down his throat. When a female gorilla succumbs to Ebola, no one measures the rate of her breathing or checks for a telltale rash. Thousands of gorillas may have been killed by the virus but no human has ever attended one of those deaths - not even Billy Karesh, not even Alain Ondzie. A small number of carcasses have been found, some of which have tested positive for Ebola antibodies. A large number of carcasses have been seen and reported by casual witnesses, in Ebola territory at Ebola times, but because the forest is a hungry place, most of those carcasses could never be inspected and sampled by scientific researchers. "

― David Quammen , Spillover: Animal Infections and the Next Human Pandemic