This helps warm incoming cold air before entering their lungs. Reindeer also travel, feed, and rest together in the wild, sometimes forming super-herds of up to 500,000 animals. Tundra reindeer ...

Mountainous areas are also very cold. Cold environments are found at higher latitudes and higher altitudes. They include polar, tundra and mountain, or alpine, biomes. Cold environments face ...

In the far north of our planet lies the largest land habitat on earth, home to snow-covered forests and the icy open tundra.