Bison along the Bitterroot Valley's Eastside Highway north of Stevensville, Montana, are covered in snow following a blizzard on November 23, 2010. (Photo by Perry Backus/The Missoulian)

A monarch butterfly rests on a visitor's hand at the Monarch Grove Sanctuary in Pacific Grove, California December 30, 2014. Monarch butterflies may warrant U.S. Endangered Species Act protection because of farm-related habitat loss blamed for sharp declines in cross-country migrations of the orange-and-black insects, the U.S. Fish and Wildlife Service said. (Photo by Michael Fiala/Reuters)

Indian tourists walks during heavy snowfall by Dal Lake in Srinagar on January 6, 2017. The sub-zero temperatures has frozen many water bodies in Kashmir and even drinking water taps have frozen at some places. (Photo by Tauseef Mustafa/AFP Photo)

A woman toes a tube carrying a man during the Ice and snow carnival at Taoranting park in Beijing, China, January 25, 2016. (Photo by Kim Kyung-Hoon/Reuters)

A street vendor warms his foot around a fire during cold weather in the rebel-controlled area of Maaret al-Numan town in Idlib province, Syria, January 4, 2016. (Photo by Khalil Ashawi/Reuters)

“I have been photographing this group of urban foxes in Bristol for over 12 months; what started off as a chance encounter has become an obsession for me and has changed my feelings and attitudes towards urban foxes forever...”. – Ian Wade. (Photo by Ian Wade)

Two men play golf with a tennis ball as a snowstorm sweeps through Times Square, Tuesday, March 14, 2017, in New York. (Photo by Mark Lennihan/AP Photo)

A reveller wearing a golden cape celebrates as the sun rises during the winter solstice at Stonehenge on Salisbury plain in southern England December 22, 2014. The winter solstice is the shortest day of the year, and the longest night of the year. (Photo by Dylan Martinez/Reuters)