The western black rhino, one of four subspecies of black rhino, is now a thing of the past, according to the International Union for Conservation of Nature's "Red List." The group has declared the black rhino species native to West Africa extinct and says another rhino species, Central Africa's northern white rhino, is "possibly extinct in the wild," the BBC reports. The two species were found in areas where poachers were active and protection minimal.
The IUCN warns that a quarter of all mammals are at risk of extinction. In some areas, however, conservation efforts are paying off. The numbers of the southern white rhino species has risen from 100 at the end of the 19th century to around 20,000 today. "In the case of both the western black and the northern white rhinos the situation could have had very different results if suggested conservation measures had been implemented," an IUCN spokesman says. Poachers killed Vietnam's last rhino earlier this year. (Read more rhinoceros stories.)