People take pictures of deer in the Phoenix Park in Dublin, Ireland December 5, 2016. (Photo by Clodagh Kilcoyne/Reuters)

Only 156 people remained in the tribe when Jan visited in Accham District, Nepal, January 2016. Hidden deep in the Himalayan forest is one of the world’s last enduring nomadic tribes who are resisting attempts to move them into permanent settlements. (Photo by Jan Moller Hansen/Barcroft Images)

A man waits with his camel to take part in a camel decoration competition at the Nagaur Cattle Fair, where animals like camels, cows, horses, and bulls are brought to be sold or traded, in Nagaur, in the desert state of Rajasthan, India February 2, 2017. (Photo by Himanshu Sharma/Reuters)

View of an American marine as he lies in a foxhole and whistles at a husky, one of the scouting dogs used during the landing on Guam, August 1944. (Photo by W. Eugene Smith/Time & Life Pictures/Getty Images)

A U.S. Marine leads training on a shooting range in France in an undated photo taken during the First World War. (Photo by Reuters/Courtesy Library of Congress)

A stork-billed kingfisher (Pelargopsis capensis) is seen perched on a tree during monsoon rain on July 25, 2016 in Bintan, Indonesia. The stork-billed kingfisher is a tree species which is widely but sparsely distributed in the tropical Indian subcontinent and Southeast Asia, from India to Indonesia. This kingfisher is resident throughout its range. It is very large, measuring 35 to 38 cm (14 to 15 in) in length. The adult has a green back, blue wings and tail, and grey head. (Photo by Sijori Images/Barcroft Images)

An air tanker drops fire retardant on flames as firefighters continue to battle against the Detwiler fire in Mariposa, California on July 19, 2017. The Detwiler fire is currently at 7 percent containment and has burned more than 45,000 acres and destroyed eight structures. (Photo by Josh Edelson/AFP Photo)

People stand by a damaged car at a train station at a makeshift camp for migrants and refugees at the Greek-Macedonian border near the village of Idomeni, Greece, May 10, 2016. (Photo by Marko Djurica/Reuters)