Kenya Wildlife Service and Save The Elephants staff push an elephant as they undertake the collaring of ten elephants ranging near the Standard Gauge Railway to fit them with advanced satellite radio tracking collars in Tsavo National Park, Kenya March 15, 2016. (Photo by Goran Tomasevic/Reuters)

People of pro-government groups, with Russian flags, dance marching through downtown Moscow to mark People's Unity Day, a public holiday, in Russia, on Tuesday, November 4, 2014. Russia marks National Unity Day on November 4 to celebrate the defeat of Polish invaders in 1612. (Photo by Ivan Sekretarev/AP Photo)

Tanzania, 1964. A touching moment between primatologist and National Geographic grantee Jane Goodall and young chimpanzee Flint at Tanzania's Gombe Stream Reserve. (Photo by Hugo van Lawick via National Geographic)

Students feed fruit to an elephant during Thailand's National Elephant Day in the ancient Thai capital Ayutthaya March 13, 2015. Thais honoured the elephant on Friday with special fruits and Buddhist ceremonies across the country to pay homage to their national animal. (Photo by Athit Perawongmetha/Reuters)

Chinese hostesses, who serve the delegates of the Chinese People's Political Consultative Conference and National People's Congress, have souvenir photos taken in front of the Great Hall of the People during sessions of the CPPCC and NPC held in Beijing, China Tuesday, March 4, 2014. (Photo by Andy Wong/AP Photo)

Motorcycling, Gotland Grand National 2016 endure race, Gotland, Sweden on October 29, 2016. Riders compete. (Photo by Soren Andersson/Reuters/TT News Agency)

A female participant of the Bela Negara – “defend the nation” – programme applies camouflage face paint on another participant's face at a training centre in Rumpin, Bogor, West Java, Indonesia June 2, 2016. (Photo by Darren Whiteside/Reuters)