Camera trapper Xavier Hubert-Brierre put this large mirror on the side of a road through the jungle in Gabon and left a camera there to record how the animals would respond to their own reflections. A silverback gorilla thought it was seeing another silverback and responded by trying to scare off the potential challenger… (Photo by Xavier Hubert-Brierre/Johns Hopkins University Press)

Workers polish a snow sculpture ahead of the 16th Harbin Ice and Snow World in Harbin, Heilongjiang province, December 22, 2014. The 16th Harbin Ice and Snow World will be officially opened on January 5, 2015. (Photo by Reuters/Stringer)

“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)

Elephants spray tourists with water in celebration of the Songkran water festival in Thailand's Ayutthaya province, about 80 km (50 miles) north of Bangkok, April 9, 2014. (Photo by Rungroj Yongrit/EFE)

The Sydney Skyline is seen before the lights are switched off for Earth Hour on March 26, 2011 in Sydney, Australia. Earth Hour encourages individuals around the world to turn off their lights for one hour at 20:30 local time on March 26, 2011 to take a stand against climate change. The largest Earth Hour was in 2010 when 128 countries participated.

Katjinga, a Rhodesian ridgeback dog who lives on a 20-acre farm in Germany, adopted an abandoned pot-bellied piglet in August 2009. The tiny black piglet, named Paulinchen, had been so small at birth that her mother likely overlooked it. Katjinga's owner, Roland Adam, found the piglet alone and cold and brought it to his 8-year-old dog. (Photo by Fame Pictures)

A car stands destroyed by debris, one day after a magnitude 5.1 quake killed at least 9 people, on May 12, 2011 in Lorca, Spain. After spending the night outside, residents of the historic Spanish town are awaiting the safety assessment of their houses to see wether they can return home or not. (Photo by Jasper Juinen/Getty Images)

Activists protesting cuts in subsidies to solar power in Germany protest outside the building where Vice Chancellor and Economy Minister Philipp Roesler and Environment Minister Norbert Roettgen were announcing the cuts on February 23, 2012 in Berlin, Germany. (Photo by Sean Gallup/Getty Images)