In a sobering snapshot:
In light of the danger that Ebola poses, steps are underway to create a great ape vaccine, which has been championed by primatologists like the University of Cambridge's Peter Walsh. (Likewise, researchers are developing a human vaccine, but it is not yet licensed for widespread use.) Early trials of the ape vaccine are promising, though the hurdle of inoculating skittish wild gorillas and chimps will be tough to clear.
Assigning Ebola the title of biggest threat to great apes, however, places too much blame on disease. Such a heavy crown, sadly, belongs to humans.
"The number one threat is still, by far, the bushmeat trade and the logging industry," Caillaud said, echoing conservation groups like the WWF. A 2009 undercover investigation in the Republic of the Congo, for instance, found that a single group of poachers halved a local gorilla population in 12 months; an estimated 300 gorillas, the investigators said, were sold in the country in the course of a year.