The arctic hare, or polar rabbit, is a species of hare which is adapted largely to polar and mountainous habitats. The arctic hare survives with a thick coat of fur and usually digs holes in the ground or under snow to keep warm and sleep. Arctic hares look like rabbits but have shorter ears, are taller when standing, and, unlike rabbits, can thrive in cold climates. They can travel together with many other hares, sometimes huddling with dozens or more, but are usually found alone, taking, in some cases, more than one partner. The arctic hare can run up to 60 kilometres per hour (40 mph). Its predators include the arctic wolf, arctic fox, and ermine.

Sami people from the Vilhelmina Norra Sameby, gather their reindeers herd in a corral for selection and calf labelling on October 27, 2016 near the village of Dikanaess, about 800 kilometers north-west of the capital Sweden. Sweden's Sami reindeer herders have more than hungry predators to worry about in the cold night, as the indigenous minority moves its flock to the winter pasture in the Nordic tundra. (Photo by Jonathan Nackstrand/AFP Photo)

Golden-crowned Kinglets boldly bear their flashy lemon-yellow crest and a black eyebrow stripe. Taking a good look at them might be rather challenging, since they spend most of their time in the dense fir foliage or spruce. However, if you’re patient enough to find them, listen for their shrill, thin song. Though these “little Kings” are only a tad bit larger than a hummingbird, they can survive easily extreme cold by huddling close together. They breed in montane west and the far north and only visit North America during winter.

The Atlantic Puffin is definitely a curious-looking bird. The special coloring that this bird develops for the breeding season in the spring is very reminiscent of tropical birds. The bright colors of the beak and the markings around the eyes serve no particular advantage and have evolved as a result of sexual selection. However, Puffins don’t look that pretty all year round. They shed all these festive colors in partial moult after the breeding season is over. They lose the ornaments around their eyes, their face becomes darker, and their beak becomes very different. The natural habitat of these birds is the cold waters of the North Atlantic Ocean.

NASA says it could be another 20 years before humans touch down on Mars, but in a sense, the Mars Society has been exploring the red planet for more than a decade – in Utah. Photo: Csilla Orgel, a geologist of Crew 125 EuroMoonMars B mission, makes her way back to the Mars Desert Research Station (MDRS) in the Utah desert March 3, 2013. The MDRS aims to investigate the feasibility of a human exploration of Mars and uses the Utah desert's Mars-like terrain to simulate working conditions on the red planet. Scientists, students and enthusiasts work together developing field tactics and studying the terrain. All outdoor exploration is done wearing simulated spacesuits and carrying air supply packs and crews live together in a small communication base with limited amounts of electricity, food, oxygen and water. Everything needed to survive must be produced, fixed and replaced on site. (Photo by Jim Urquhart/Reuters)

Every year National Parks Week gives visitors a chance to celebrate the incredible woodland spaces around the UK. This year the National Parks Week runs from 28 July – 3 August and there are 10 national parks across England to explore. Each one has created a special event to celebrate the National Parks Week, from picnics and treasure hunt in the park to cycle rides, safari or outdoor art exhibition. (Photo by Diana Jarvis/VisitEngland)

Swans swim over a lake, with the air temperature at about minus 35 degrees Celsius (minus 31 degrees Fahrenheit) as steam ascends above the water during sunset near the village of Urozhainy, Sovetsky district of Altai region, January 26, 2015. About 600 swans annually migrate to the lake, which is heated by warm springs, where they spend their winter being fed by yagers, which helps them to survive the severe cold. (Photo by Andrei Kasprishin/Reuters)

A golden huddle by Minqiang Lu, China. Two females and a male golden snub-nosed monkey huddle together to keep warm in the extreme cold. Threatened by forest loss and fragmentation, this endangered species is confined to central China. Restricted to living high up in the temperate forests, these monkeys – here in the Qinling mountains in Shaanxi province – feed mostly in the trees, on leaves, bark, buds and lichen. In heavy wind and snow, Minqiang walked up the mountain carrying his equipment. He stayed for half an hour in temperatures of –10C opposite the tree where the group was huddled before achieving this eye-level composition. (Photo by Minqiang Lu/Wildlife Photographer of the Year)