A giant river otter, the world's largest otter species, looks out of its enclosure at the newly completed River Safari in Singapore, on March 25, 2013. (Photo by Wong Maye-E/Associated Press)

These photographs of hundreds of ducks following their leader down a river are truly mesmerizing. Rafeur Rahman of Bangladesh climbed a high bridge and saw hundreds of ducks apparently playing a game of follow the leader. More than 500 ducks live on the river, where the mosses and snails provide the perfect habitat. Here: Ducks in the river Baral in Bangladesh. (Photo by Rafeur Rahman/Caters News Agency)

Ice covered leafs are pictured on a tree near Amstall in northern Austria, December 2, 2014. Freezing fog and rain covered parts of the region with ice, causing blocked roads due to fallen trees and closed schools for security reasons, local media report. (Photo by Heinz-Peter Bader/Reuters)

These stunning photos act as postcards for one photographer, who has traveled all over the globe, braving freezing temperatures to create the ultimate time lapse video. Photographer Dustin Farrell, 36, spent four years perfecting his technique and traveling all over the world in his quest to capture the most beautiful time lapses of nature. (Photo by Dustin Farrell/Caters News)

A competitor in fancy dress emerges from muddy water during the Tough Guy Challenge endurance race on January 29, 2012 in Telford, England. Every year thousands of people run the 8 mile assault course which involves freezing temperatures, fire and ice. (Photo by Michael Regan/Getty Images)

Fred Fugen seen training for a jump over Austria on May 12, 2014. Fearless skydivers jump from an altitude of 10,000 meters above the largest mountain in Europe. Frederic Fugen, 34, and Vincent Reffet, 29, leapt from a plane in the freezing skies above Mont-Blanc in the French Alps. The jump is from such a height the pictures show the curvature of the earth. (Photo by Dominique Daher/Barcroft Media)

A) 1st place WINNER – Roy Rimmer. “This rat was in an outdoor set I made, the set up is two meters long and a meter wide made of Perspex,it has a plywood front with holes cut in for my camera and flash guns, I placed two rusty paint cans in the set up and the rat would leap from one can too the other, I had to use flash to freeze the action”.

Growing cities, overuse of fertilizers and factory wastewater have degraded China's water supplies to the extent that half the nation's rivers and lakes are severely polluted. China aims to spend $850 billion to improve filthy water supplies over the next decade, but even such huge outlays may do little to reverse damage caused by decades of pollution and overuse in Beijing's push for rapid economic growth. Photo: Fishermen row a boat in the algae-filled Chaohu Lake in Hefei, Anhui province, June 19, 2009. (Photo by Jianan Yu/Reuters)