Hundreds of adult wood storks gather on the tops of trees at the Harris Neck National Wildlife Refuge. Stephen B. Morton/AP hide caption

itoggle caption Stephen B. Morton/AP

The European eagle owl, like this one from the Mulhouse Zoo in eastern France, is one of the largest owl species, with a wingspan of about 6 feet. Sebastien Bozon/AFP/Getty Images hide caption

itoggle caption Sebastien Bozon/AFP/Getty Images

Coleen Schaefer (left) and Doni Sprague display a tiger pelt that was confiscated and is being stored at the National Wildlife Property Repository on the outskirts of Denver. Some 1.5 million items are being held at the facility. The Trans-Pacific Partnership, which is still under negotiation, would punish wildlife trafficking. Jackie Northam/NPR hide caption

itoggle caption Jackie Northam/NPR

P22, a 4-year-old male mountain lion known as the "Hollywood Lion," is known to traverse the hills in and around Los Angeles. He is seen here recaptured by the National Park Service in March after being exposed to rat poison. AP Photo/National Park Service hide caption

itoggle caption AP Photo/National Park Service

Two adult white rhinos stand in an enclosure at South Africa's Entabeni Safari Conservancy in 2012. Entabeni is one of the world's only dedicated orphanages for rhino calves whose parents were poached for their horns — a trend that is rising. Stephane De Sakutin/AFP/Getty Images hide caption

itoggle caption Stephane De Sakutin/AFP/Getty Images