A baby Asian elephant, born only two days before, stands next to his mother Nova in its enclosure at Tierpark Berlin Zoo on May 10, 2012 in Berlin, Germany. The male elephant calf, who does not have a name yet, weighs 102kg and is 91cm tall. (Photo by Timur Emek/dapd/Sean Gallup)

Chinese woman Duo Zirong feeds stray cats at her home February 14, 2006 in Shanghai, China. Duo Zirong, a Daur ethnic minority group woman from Inner Mongolia and reported as the “Cat Woman”, has housed about 300 cats with her Shanghainese husband Liu Junluo and mother-in-law. (Photo by China Photos/Getty Images)

Ten day old male Gorilla “Fataki” clings to his mother “Frala” during his media debut at Taronga Zoo June 4, 2003 in Sydney, Australia. Fataki was born on May 24, 2003 and was the fourth Gorilla to be born at Taronga Zoo since the opening of the Gorilla Forest in 1997. (Photo by Chris McGrath/Getty Images)

Vehicles clog a highway during a hazy day in Beijing, China, Wednesday, February 26, 2014. Beijing remained cloaked in hazardous white pollution hiding much of its skyline Wednesday, despite the announced closures or production cuts at 147 of the city's industrial plants. (Photo by Ng Han Guan/AP Photo)

A wildlife ranger strokes a northern white rhino, only three of its kind left in the world, ahead of the Giant Club Summit of African leaders and others on tackling poaching of elephants and rhinos, Ol Pejeta conservancy near the town of Nanyuki, Laikipia County, Kenya, April 28, 2016. (Photo by Siegfried Modola/Reuters)

Yenny Mamani "Marta la Altena", top, grabs Leonor Cordova "Angela la Simpatica" in a hold during a Bolivian wrestling Cholitas fight in Madrid, Spain, Thursday October 8, 2015. (Photo by Paul White/AP Photo)

A Black Pete interacts with children during the arrival of Sinterklaas, or Saint Nicholas, in Maassluis, Netherlands, Saturday, November 12, 2016. Sinterklaas and his helper Black Pete are at the center of a long-time controversy because Pete is often played by white people in blackface makeup. (Photo by Peter Dejong/AP Photo)

Children, some in tears, are escorted down a road in Barcelona, Spain, Thursday, August 17, 2017. Police in Barcelona say a white van has mounted a sidewalk, struck several people in the city's Las Ramblas district. (Photo by Manu Fernandez/AP Photo)