The Arctic tundra may be a cold and desolate place, but many animals call it home. Of course, the biodiversity in this biome is small compared to others, but there are approximately 50 different species living there. Animals in the tundra must be well adapted to this inhospitable environment. Many have thick layers of fur and/or blubber (fat) to keep them warm. Birds have layers of feathers to insulate their bodies as well. Since the summers are so short and much of the year is below freezing, animals must be able to give birth and begin raising their young in that small window of time when the weather is warm enough to welcome new life.