Nearly half of the world's 634 types of primates are in danger of becoming extinct because of human activity, according to a scientific review presented Aug. 5.

Scientists meeting at the International Primatological Society Congress in Edinburgh, Scotland, hope the report — which counts species and subspecies of primates across the world — will help spur global action to defend mankind's nearest relatives from deforestation and hunting.

In the most comprehensive review of the world's apes, monkeys and lemurs in 12 years, primatologists warned that species from the giant mountain gorillas of Central Africa to the tiny mouse lemurs of Madagascar are on the "Red List" for threatened species maintained by the International Union for Conservation of Nature, or IUCN.