Further north, another cold weather survivor truly clings to life, one of the rarest birds in the world, the critically endangered Siberian White Crane. About 3,500 remain worldwide and only four birds in western Siberia, breeding pairs are precious. After spending the worst of winter in China, they travel almost 5,000 kilometers to breed in the isolated wilderness of the Russian tundra. With so few birds, their monogamy works against them making breeding partners tough to find. But when they connect, both parents raise their young. The female lays two eggs, though generally only one chick will live. As their winter sites shrink, so does their chance for survival.

 

Elsewhere secretive animals lurk in forested shadows. With a face like a kangaroo and a vampire's teeth, the musk deer makes its timid way through the woods in search of lichens. Don't be fooled by the fangs: males grow them for display instead of antlers. The older the deer, the longer the fangs. But it's the other end of the deer that attracts more attention, the male's musk gland produces a scent that's irresistible to does and perfume makers.