Swedish brown bears “Fred” and “Frode” play in the snow on January 30, 2014 at the Natur- und Umweltpark (NUP) animal park in Guestrow, northeastern Germany. Despite of icy temperatures, the bear brothers took a break from their winter rest. (Photo by Bernd Wuestneck/AFP Photo/DPA)

The fourth annual BigPicture Natural World Photography Competition aims to celebrate the diversity of life on Earth, and encourages people to protect and conserve it. Here: “The Salmon Catchers”. Terrestrial Wildlife. To capture this view of a mother grizzly bear and her cub, photographer Peter Mather set up a camera trap on a log that he knew the bears tended to traverse while fishing for salmon, in the Yukon River watershed in Canada. (Photo by Peter Mather/BigPicture Natural World Photography Competition 2017)

A adorable bear cub cant get enough of playing buckaroo – as it hangs onto its mum splashing about in a river. His mum was attempting to catch a fish supper for the pair as the plucky cub continued to jump on her back. And as she was concentrating on her meal the young bear became a distraction. So she sprung into life with him on her back before he was tossed into the water much to his delight. (Photo by Lisa Sidorsky/Caters News)

The Paddington Bear balloon floats down Central Park West during the 90th annual Macy's Thanksgiving Day Parade on November 24, 2016 in New York. (Photo by Kena Betancur/AFP Photo)

Scarlett points at the huge ice sculpture of a bear during a Photocall for Magical Ice Kingdom at Hyde Park Winter Wonderland at Hyde Park on November 17, 2016 in London, England. It is the event's 10th anniversary this year. (Photo by Ben Perry/Getty Images)

In this August 1, 2014 photo provided by the National Park Service are male caribou antlers in the Oolah Valley, likely the result of a grizzly kill as he migrated south for the winter at the Arctic National Park and Preserve in Alaska. The nation's northernmost national park says its new management plan will have to consider the effects of a new industrial road to the mining district of Ambler, the first road that would be constructed within its Maryland-sized boundaries. (Photo by Cadence Cook/AP Photo/National Park Service)

Aline, along with other rangers and park staff visit the gorilla's in the parks Mikeno sector, where the majority of the gorilla families live in Virunga National Park. Therefore there has been a surge of poaching and violence in the area. For the first time, women have taken up the most dangerous job in wildlife, becoming para-military rangers at the Virunga National Park in DR Congo. (Photo by Monique Jaques)

Photographer Gregg Segal travelled the world to document children and the food they eat in a week. Partly inspired by the increasing problems of childhood obesity, he tracked traditional regional diets as yet unaffected by globalisation, and ironically, found that the healthiest diets were often eaten by the least well off. (Photo by Gregg Segal/The Guardian)