A walruses at Hagenbeck Zoo in Hamburg, Germany on July, 7, 2015. (Photo by Werner Struss/Startraks action)

Japan's delegation gather to sign the formal surrender document on the U.S. Navy battleship USS Missouri in Tokyo Bay in a September 2, 1945 file photo. (Photo by Reuters/US Navy)

In this August 17, 2016, photo, from left to right, Chhering Chodom, 60, Tashi Yangzom, 50, Lobsang Chhering, 27, and Dorje Tandup, 58, drink milk tea on the side of the road. For centuries, the sleepy valley nestled in the Indian Himalayas remained a hidden Buddhist enclave forbidden to outsiders. Enduring the harsh year-round conditions of the high mountain desert, the people of Spiti Valley lived by a simple communal code – share the Earth's bounty, be hospitable to neighbors, and eschew greed and temptation at all turns. That's all starting to change, for better or worse. (Photo by Thomas Cytrynowicz/AP Photo)

A boy carries sugar cane through a farm on the outskirt of Zaria in Nigeria's northern state of Kaduna November 15, 2016. (Photo by Akintunde Akinleye/Reuters)

JAPAN: A businessman stands at a pond in the Kyu-Shiba-rikyu Garden on a warm and sunny day in Tokyo, Japan, March 18, 2016. (Photo by Thomas Peter/Reuters)

Macaque monkeys crowd together in their cage at a monkey farm on February 3, 2016 in Xinye county, Henan province, China. The area boasts a centuries-long and lucrative history of raising and training monkeys for performance. In Xinye, villagers are seeing an increase in business with the lunar calendar's “Year of the Monkey”. Farmers say most of the monkeys are bred and raised for domestic zoos, circuses, and performing groups, but add that some are also sold for medical research in China and the United States. Despite the popularity of the tradition, critics contend the training methods and conditions constitute animal cruelty. (Photo by Kevin Frayer/Getty Images)

In this March 17, 2015 photo, Ashaninka Indian men, identified by locals as illegal loggers, tie tree trunks together to move them along the Putaya River near the hamlet of Saweto, Peru. Illegal logging persists unabated in this remote Amazon community where four indigenous leaders who resisted it were slain in September. The Putaya River is the waterway that transports felled trees, cut both legally and illegally, to the city of Pucallpa. (Photo by Martin Mejia/AP Photo)

Aerial view of tourists in life vests and rubber rafts in the Grand Canyon of western Henan, Sanmenxia, China on August 5, 2017. (Photo by Imaginechina/Rex Features/Shutterstock)