1/5 of known mammal species

URL: http://www.stallman.org/archives/2009-sep-dec.html#04%20November%202009%20%281%2F5%20of%20known%20mammal%20species%29

04 November 2009 (1/5 of known mammal species)

1/5 of known mammal species are threatened due to human activity. The danger is worse for other kinds of vertebrates.