Rhino Subspecies Extinct; 25 Percent of Mammals at Risk Globally

One-quarter of the world’s mammal species are at risk of extinction, and a subspecies of rhinoceros — the Western Black Rhino — has officially gone extinct, according to the new Red List of Threatened Species compiled by the International Union for Conservation of Nature (IUCN). In addition to the loss of the Western Black Rhino, which was found in west-central Africa, at least two other subspecies of rhinoceros are “teetering” on the edge of survival in the face of increased illegal poaching of the animals for their horns, according to the IUCN. Numerous plant species are also disappearing, the group said, including the West Himalayan yew, or Taxus contorta, a tree that is used to produce the chemotherapy drug Taxol. The IUCN list changed the status of the tree, which is found in Afghanistan, India, and Nepal, from “vulnerable” to “endangered” because of over-exploitation. Of the more than 61,900 species the IUCN reviewed for its latest assessment, 801 species are extinct, 64 are extinct in the wild, and another 3,879 are “critically endangered.”