Notes on a Holiday Deer

Charley the cold-nosed caribou doesn't have quite the same ring as Rudolph the red-nosed reindeer, but why shouldn't caribou qualify for places on Santa's sled team? Are there any true differences between caribou and reindeer?

There's only one really good answer: ten thousand years of domestication.

Caribou certainly look like reindeer. Both female reindeer and female caribou grow antlers; they are the only deer-family females that can do so. Both animals are classified taxonomically under the same Latin name, Rangifer tarandus, which means that scientists think they are the same animal.

The deer themselves don't see any significant differences. In fact, the animal that most worries the reindeer herders on Alaska's Seward Peninsula isn't a mighty predator nor a disease-bearing insect--it's caribou. When a migrating caribou herd sweeps past, domestic reindeer are likely to hear the call of the wild and join right along. That kind of mass elopement leads to perfectly healthy babies, all indistinguishable from normal caribou calves.

Or nearly so. An albino animal, with white hair and pink eyes and nose, is nearly certain to be a reindeer (or have reindeer parentage). Albinos don't do well in the wild, but human herders can protect these usually weaker animals and are willing to do so because snow-white hides are valuable. A caribou marked like a pinto pony, with white splotches on a dark coat, is likely to be a reindeer as well. The dramatic markings could make the spotted animal a better target for wolves, for example, so a free-living brightly spotted animal would be at a disadvantage. In a protected herd, the coloring wouldn't matter--or might even be preferred by a herder with an eye toward a distinctive parka.

Then too, reindeer are often a bit chunkier-looking than caribou. That seems a reasonable alteration in an animal domesticated for thousands of years as a beast of burden and source of meat.

What may not seem reasonable is how few alterations domestication has brought to the basic wild type over the great length of time that humans have kept reindeer. According to a brochure from the University of Alaska Fairbanks's Cantwell Reindeer Research Station, there's evidence that reindeer were first domesticated near Lake Baikal, in Siberia, by about 8,000 B.C. That's earlier than cattle or horses were tamed, yet we've exploited the natural variability in those species to breed cattle in an array of shapes, sizes, and colors, giving gallons of milk or hundreds of pounds of beef, and to breed horses ranging from miniature ponies to Clydesdales. But reindeer still look almost exactly like caribou.

The likely explanation is that the way of life for these deer didn't change much with domestication. Herds still migrate long distances, necessary mainly because of the slow- growing plants they eat--they'd destroy their food supply if they stayed in one place. Thus, it is an advantage for a reindeer to be designed to cover ground as a member of a group: extremely slow or small ones would lag behind and be lost, extremely fast ones would be alone and vulnerable in front, extremely big ones would need too much too eat.

It was only when people settled down that they could deal with--for example--fancy race horses needing special foods and protection from the rigors of life with the common herd. In Scandinavia, the reindeer herders never settled down. They move with the deer. The reindeer never had much pressure to change.

They now differ from caribou in one important regard, however. Even though they are classed as semi-domesticated animals, they have tamed down quite a bit. (It makes sense that people dealing with them would prefer stock that would neither panic nor charge at the first provocation.)

So if you ever encounter a remarkably well-mannered caribou, it's probably a reindeer. In fact, it's fortunate that whoever was responsible gave Santa reindeer rather than caribou to pull his sleigh. Caribou would be most unlikely to cooperate on a whirlwind, worldwide tour of housetops.