ZOO-ology column: Science suggests female reindeer pull Santa's sleigh
Dec. 11, 2011 at 6:11 a.m.
By Judie Farnsworth
In keeping with the holiday season, a little information about reindeer seems timely (the ones with normal noses.)
They are a member of the deer family living in northern areas of arctic Europe, Asia and North America. In North America they're referred to as caribou and are essentially the same animal. Caribou are generally thought to be wild where reindeer are often domesticated. In some parts of the world, reindeer are herded and sources for milk, cheese, butter, hides for clothing, transportation and meat. Antlers may be used to make utensils and tools.
They're ruminants (cud-chewing animals) and herbivores (plant eaters). Like sheep and cows, they have a four-chambered stomach. They like quite a healthy diet of lichens, herbs, leaves and fungi, but twigs will be eaten when food is scarce. The "normal nose" of a reindeer has a wider surface within the nostrils. Body heat warms icy air before it enters the lungs. Moisture when breathing out is captured for use by the body before it is exhaled.
Reindeer are the only deer species with both females and males having antlers. Even the calves have two little bumps for antlers. Males usually shed theirs early in the winter and females in the spring, after young are born. New antlers will grow during the spring and summer. Females (and sometimes males) are known to encircle their young, antlers facing outward if threatened.
Reindeer are excellent swimmers and able to cross wide rivers. An outer layer of tubular hairs makes them more buoyant. A substantial, wooly undercoat insulates from the cold. It holds body heat so effectively, that a reindeer may lie on snow without it melting.
Hoofs are large and can adapt seasonally. They're wider and spongy in the summer for better traction on soft ground. In the winter, the spongy surface shrinks. The edge of the hoof is exposed and cuts into ice and snow for extra hold. They also use their hooves to dig beneath ice and snow for food. This is known as cratering. Wild reindeer or caribou are migratory. They travel in herds moving long distances to the north during warmer months and south to better feeding areas during winter.
Now - there's been this rumor floating around that since Santa's reindeer all have antlers and males almost always shed theirs by mid-December - every last one of them must be female! One gentleman several years ago responded thus - "We should have known this. Only women would be able to drag a fat man in a red velvet suit all around the world in one night - and not get lost." Hmmm.
Judie Farnsworth is a longtime volunteer at the Texas Zoo specializing in educational programs.