Reindeer vs. Caribou

This originated on this thread
http://davesgarden.com/community/forums/t/796574/

"If you remove the reins from a reindeer, why do we call it a Caribou?"

I've researched this and found:
There are 3,000,000 legitimate domesticated driveable reindeer. They are one of the oldest domestic species.
Wild subspecies in isolated locations may be called either. The difference between a Coastal Reindeer and a Coastal Caribou is only the neighborhood.

Hunters in Alaska only have one chance to shoot a Caribou at the northern or southern ends of the migration. In between their are two chances one northbound and one southbound. Big game ranches in Alaska have solved the migration problem by importing pet reindeer from Europe. They can be killed year round in the same location. That seems to be lacking sport.

Merry Xmas & Happy New Year