15,589 species threatened

More than 15,000 species around the world are at risk of extinction, according to a report released today (November 17) by the International Union for Conservation of Nature and Natural Resources (IUCN). The organization, whose annual list of endangered species is commonly known as the "Red List," found that one in eight birds, almost half of turtles and tortoises, one in four mammals studied, and one in three amphibians is threatened.

"We are in the midst of the sixth great extinction wave on the planet Earth, caused by the intervention of humans," David Brackett, Species Survival Commission Chair of the study, told The Scientist. "Species should come and go on an evolutionary time scale, not on our time scale." Brackett said that "objective information is showing that declines are not limited to vulnerable species, but are happening across the entire taxonomic spectrum."

The report, released at the Third IUCN World ...