The author's 1972 census, following one the previous year, of the mountain gorillas in the Virunga Volcanoes, which straddle the Zaire–Rwanda–Uganda borders, shows a small but still declining population. All the signs, including the behaviour of the gorillas, one of which fled screaming at the sight of one of the observers, suggests that the decline is due largely to human interference. As the entire area has national park or game reserve status the urgent need is to enforce the law.