National Geographic (Lynx)

The lynx is a solitary cat that haunts the remote northern forests of North America, Europe, and Asia. Lynx are covered with beautiful thick fur that keeps them warm during frigid winters. Their large paws are also furry and hit the ground with a spreading toe motion that makes them function as natural snowshoes.
These stealthy cats avoid humans and hunt at night, so they are rarely seen.
There are several species of lynx. Few survive in Europe but those that do, like their Asian relatives, are typically larger than their North American counterpart, the Canada lynx.
All lynx are skilled hunters that make use of great hearing (the tufts on their ears are a hearing aid) and eyesight so strong that a lynx can spot a mouse 250 feet (75 meters) away.
Canada lynx eat mice, squirrels, and birds, but prefer the snowshoe hare. The lynx are so dependent on this prey that their populations fluctuate with a periodic plunge in snowshoe hare numbers that occurs about every ten years. Bigger Eurasian lynx hunt deer and other larger prey in addition to small animals.
Lynx mate in early spring or late winter. About two months later, females give birth to a litter of one to four young.

Humans sometimes hunt lynx for their beautiful fur. One endangered population, the Iberian lynx, struggles to survive in the mountains of Spain, far from the cold northern forests where most lynx live.

National Geographic (Artic Fox)

The arctic fox is an incredibly hardy animal that can survive frigid Arctic temperatures as low as –58°F (-50°C) in the treeless lands where it makes its home. It has furry soles, short ears, and a short muzzle—all-important adaptations to the chilly clime. Arctic foxes live in burrows, and in a blizzard they may tunnel into the snow to create shelter.

Arctic foxes have beautiful white (sometimes blue-gray) coats that act as very effective winter camouflage. The natural hues allow the animal to blend into the tundra's ubiquitous snow and ice. When the seasons change, the fox's coat turns as well, adopting a brown or gray appearance that provides cover among the summer tundra's rocks and plants.
These colorings help foxes to effectively hunt rodents, birds, and even fish. But in winter prey can be scarce on the ground. At such times, arctic foxes will follow the region's premier predator—a polar bear—to eat the leftover scraps from its kills. Foxes will also eat vegetables when they are available.
Like a cat's, this fox's thick tail aids its balance. But for an arctic fox the tail (or "brush") is especially useful as warm cover in cold weather.
Female arctic foxes give birth each spring to a large litter of up to 14 pups.