Today's learning moment:
Caribou & Reindeer
Rangifer tarandus

Reindeer and Caribou look different, but they probably are the same species. Caribou are large, wild, elk-like animals which can be found above the tree-line in arctic North America and Greenland. Because they can live on lichens in the winter they are very well adapted for the harsh arctic tundra where they migrate great distances each year. Caribou cows and bulls both grow distinctive antlers and bull antlers can reach 4 feet in width! A Caribou calf can run within 90 minutes of its birth. It must do this to keep up with the migrating herds.

Reindeer are slightly smaller and were domesticated in northern Eurasia about 2000 years ago. Today, they are herded by many Arctic peoples in Europe and Asia including the Sami in Scandinavia and the Nenets, Chukchi and others in Russia. These peoples depend on the reindeer for almost everything in their economy including food, clothing and shelter. Some Nenets even keep reindeer for pets! Reindeer were introduced into Alaska and Canada last century, but most attempts failed. Native peoples in these countries still prefer to hunt caribou rather than herd reindeer.



Also... reindeer are thought to be one of the only species of animal that can see ultraviolet light.
Antlers of adult males fall off in December, so I guess Santa's reindeer are all female.
Antlers of young males fall of in early spring, and antlers of females fall off in the summer.