Indonesia and Vietnam
Number remaining: fewer than 60
Perhaps the planet's rarest large mammal. Its horn is prized by poachers, and its forests are prized by developers. Both could spell doom for the species.
Sumatran Tiger
Sumatra, in Indonesia
Number remaining: fewer than 600
This small tiger has lived only in Sumatra for a million years, making it hard to escape human expansion. Most survivors dwell in reserves, but about 100 live beyond the borders of the protected areas.
Cross River Gorilla
Nigeria and Cameroon
Number remaining: fewer than 300
Thought to be extinct in the 1980s, the species is holding on, for now. Hunted for bush meat and crowded out by development, it may not last long.
Vaquita
Gulf of California
Number remaining: 200 to 300
One of the rarest cetaceans in the world, the Vaquita is endangered by both its limited range and the ease with which it gets caught in fishing nets.
Golden-Headed Langur
Vietnam
Number remaining: fewer than 70
All but wiped out, this primate was placed under protection in 2000. It is still in grave danger, but in 2003 its numbers rose for the first time in decades. (Read more...)
source: Time.com