A Southwest Airlines jet takes off from Reagan National Airport with a thunderhead to the east on June 20, 2017 in Alexandria, VA. (Photo by Jonathan Newton/The Washington Post)

An elephant from Earl's Court Circus with a man in its mouth, 1928. P.S. All pictures are presented in high resolution.

Global wildlife populations will decline by 67% by 2020 unless urgent action is taken to reduce human impact on species and ecosystems, warns the biennial Living Planet Index report from WWF (World Wide Fund for Nature) and ZSL (Zoological Society of London). From elephants to eels, here are some of the wildlife populations most affected by human activity. Here: The maned wolf is among the large mammals in the Brazilian Cerrado that are threatened by the increasing conversion of grasslands into farmland for grazing and growing crops. (Photo by Ben Cranke/Nature Picture Library/Alamy Stock Photo)

The #8 DP Starworks Motorsports Ford Rley driven by Enzo Potolicchio, Ryan Dalziel, Alex Popow, Lucas Luhr and Allan McNish runs off the track during the Rolex 24 at Daytona International Speedway on January 28, 2012 in Daytona Beach, Florida. (Photo by John Harrelson/Getty Images)

A model presents a creation of Peruvian designer Ani Alvarez Calderon during Fashion Week in Lima, Peru, April 25, 2017. (Photo by Guadalupe Pardo/Reuters)

A protester gestures as he holds a dog before a burning barricade during protests in Harare, Zimbabwe on January 15, 2019. (Photo by Philimon Bulawayo/Reuters)

Alan Cumming and Uma Thurman attend the Versace for H&M Fashion event at the H&M on the Hudson on November 8, 2011 in New York City. (Photo by Rabbani and Solimene Photography/Getty Images for Versace for H&M)

Billie Catherine Lourd and Keke Palmer must have loved their account balances so much, they posed in front of an ATM in Los Angeles on August 8, 2016. (Photo by Jen Lowery/Splash News)