When what to my wondering eyes should appear, but...
A miniature sleigh, and eight tiny . . . caribou
'Twas the night before Christmas when everyone knew, the sleigh of St. Nicholas was not pulled by caribou. That would be reindeer.
Truth be told, reindeer and caribou are the same species, Rangifer tarandus. But the two words are used in different parts of the world to describe the same animal: the arctic deer. As a general rule in North America, wild arctic deer are called caribou and domesticated arctic deer are called reindeer.
Clement Moore wrote that eight tiny reindeer pulled Santa's sleigh in his 1823 Christmas poem "A Visit from Saint Nicholas" and he was probably right.
A brilliant professor of Asian and Greek literature and a biblical scholar, Moore knew caribou were wild, and there was no written record of them ever being tamed, not even by Santa. He also knew reindeer had been domesticated for over 2,000 years and were used by to pull heavy loads, like a sleigh packed with toys.
According to Moore's famed Christmas poem, the reindeer went up on the rooftop 'click click click.' It sounds nicer than it is. Reindeer walk with a clicking sound so loud it resonates up to 150 feet away. (Imagine the sound of the 400,000-strong migration of the North American herd.) The sound is made by tendons snapping over foot bones.
Reindeer are amazingly adapted for living with Santa at the North Pole.
Large four-toed, hairy hooves expand or contract with the weather to act like snowshoes or shovels or water paddles. Specialized noses densely covered with short hair (even the nostrils) to warm cold inhaled breath because they shove these muzzles into the snow all day long to root out food.
Two layers of fur that trap air to provide first-rate insulation from arctic temperatures, keeping them afloat in freezing water or pulling sleighs at light-speed.
They can run up to 50 mph when chased. Caribou calves can follow their mothers an hour after birth and gallop up to 45 miles an hour.
Both males and females grow antlers every year and males lose theirs in early winter or early spring, but females shed theirs in the summer. Santa's reindeer are always pictured with antlers. That means they're probably she-deer or young bulls.