The Sixth Mass Extinction is Here Listen Download Embed Share Share this on Facebook (Opens in a new window) Share this on Twitter (Opens in a new window) Share this via Email Fatu, a northern white rhino female. With just five northern white rhinos left, conservationists are searching for a breakthrough that could save a population that is already effectively extinct. ( Nichole Sobecki for The Washington Post / Getty ) Produced by Mythili Rao Produced by PRI and WNYC