File photo of polar bears playing at St-Felicien Wildlife Zoo in Quebec

 
File photo of polar bears playing at St-Felicien Wildlife Zoo in Quebec
Polar bears play at St-Felicien Wildlife Zoo in St-Felicien, Quebec in this March 6, 2008 file photo. Polar bears were listed on May 14, 2008 as threatened under the U.S. Endangered Species Act because of damage to their sea ice habitat, U.S. Interior Secretary Dirk Kempthorne announced. Picture taken March 6, 2008. REUTERS/Mathieu Belanger/Files (CANADA)