“Mountain Goats, Colorado”. A herd of mountain goats huddle together on top of Mount Evans, Colorado during a lightning storm. This photo was selected out of more than 5,000 entries to go on display in “Wilderness Forever: 50 Years of Protecting America’s Wild Places”, a new photo exhibition at the Smithsonian’s National Museum of Natural History, which will run through summer 2015. (Photo by Verdon Tomajko/Smithsonian Wilderness Forever Photo Contest)

“Adventurers have gone deep underground to discover previously unexplored caves in these pictures. The awe-inspiring snaps show the cavers dwarfed by the huge series natural rock chambers in the Leye – Fengshan Geopark, China. Belgian photographer Francois-Xavier De Ruydts, 33, captured the team of explorers as they trekked through the deep wonderground in January 2014”. – Caters News. Here: Caving expedition in Fengshan, China, Guangxi province. (Photo by Francois-Xavier De Ruydts/Caters News)

Zurab Gurielidze, a director of the Tbilisi Zoo, speaks to the media while standing next to a hippopotamus named Begi at the zoo in Tbilisi, Georgia, September 13, 2015. Tbilisi zoo, which was partly destroyed and some 300 animals escaped or died in the floods that also killed at least 19 people in June, was reopened on Sunday. (Photo by David Mdzinarishvili/Reuters)

Aerial photo taken on March 4, 2017 shows cole flower fields in Luoping County, southwest China's Yunnan Province. (Photo by Xinhua/Barcroft Images)

A married couple is displayed on a pile of cheeses in the “Speciality” category during the Swiss Cheese Awards competition in Le Sentier, Switzerland September 23, 2016. One hundred and fourty-two experts have to choose the best out of 777 cheeses from 353 producers competing in 28 categories. (Photo by Denis Balibouse/Reuters)

A hunter holds a hare he just killed during a hunt in a field near the village of Novosyolki, Belarus November 5, 2016. (Photo by Vasily Fedosenko/Reuters)

Yussef Saluta (R), 20, an Israeli Arab soldier from the Desert Reconnaissance battalion takes part in a drill near Kissufim in southern Israel November 29, 2016. A battalion of soldiers crawls across the desert sand with assault rifles cocked. It's a routine exercise, but these are no ordinary troops – they are Arabs who have chosen to fight for the Jewish state. (Photo by Amir Cohen/Reuters) (Photo by Amir Cohen/Reuters)

A model gets ready backstage during a body art festival in Almaty, Kazakhstan, March 23, 2016. (Photo by Shamil Zhumatov/Reuters)