A tale of two foxes. Surprising behaviour, witnessed in Wapusk national park, on Hudson Bay, Canada, in early winter. Red foxes don’t actively hunt Arctic foxes, but where the ranges of two predators overlap, there can be conflict. Though the light was poor, the snow-covered tundra provided the backdrop for the moment that the red fox paused with the smaller fox in its mouth in a grim pose. (Photo by Don Gutoski/2015 Wildlife Photographer of the Year)

The Aletsch Glacier is pictured at dusk in Fiesch, Switzerland, August 11, 2015. One of Europe's biggest glaciers, the Great Aletsch coils 23 km (14 miles) through the Swiss Alps – and yet this mighty river of ice could almost vanish in the lifetimes of people born today because of climate change. The glacier, 900 metres (2,950 feet) thick at one point, has retreated about 3 km (1.9 miles) since 1870 and that pace is quickening. (Photo by Denis Balibouse/Reuters)

The aurora borealis, or the northern lights occur over Derwentwater, near Keswick, England, Thursday October 8, 2015. The northern lights are the result of collisions between gaseous particles in the Earth's atmosphere with charged particles released from the sun. (Photo by Owen Humphreys/PA Wire via AP Photo)

The Bolenberg chapel sits on a rise overlooking vineyards where leaves change colors to mark a change in the season in Orschwihr in the Alsace region of France, October 12, 2015. (Photo by Jacky Naegelen/Reuters)

More than 1,500 snappers submitted their most hilarious pictures of all creatures great and small, and now 45 have made the cut. From drunken-eyed owls to embarrassed chipmunks and laughing goats – the finalists in the Comedy Wildlife Photography Awards are guaranteed to raise a smile. Here: 'Dancing sifaka'. (Photo by Alison Buttigieg/Comedy Wildlife Photography Awards/Mercury Press)

Talk about being in the eye of the storm! These stunning snaps show breath-taking storms from an extraordinary up-close perspective. Taken by daredevil storm chaser Dennis Oswald, from Neuss, Germany, the amazing pictures capture spectacular storms from around the globe. Having chased storms for nearly 15 years, experienced Dennis gets right in the action to get these incredible shots. Here: scenic mothership supercell just north of Howard, Kansas. (Photo by Dennis Oswald/Caters News)

This photo provided by Netflix/naturepl.com and WWF-International shows an African Elephant (Loxodonta africana) in front of double rainbow, in Masai Mara, Kenya, included in the Netflix natural history series, “Our Planet”, in collaboration with Silverback Films and WWF. The eight-part series debuts in 2019. (Photo by Andy Rouse/Naturepl/WWF-International/Netflix via AP Photo)

These are the stunning pictures of the night sky brilliantly capturing the lights and colors of the Milky Way glistening over desert landscapes. Taken in various locations across Australia and the United States from the Grand Canyon to the Coral Sea, the pictures perfectly show the bright lights of the starry skies. Here: Bisit Badlands, New Mexico. (Photo by Wayne Pinkston/Caters News)