Several years ago, I overheard a squabble between two young boys. The older boy told the younger one that there was "no such thing as Santa Claus," so the younger boy, in order to prove the older one wrong, decided that he was going to by staying up all night on Christmas Eve just to catch a glimpse of Santa and his sleigh. The little guy could barely control his excitement. There were going to be "reindeer on the roof!"
In Europe, all caribou are called reindeer, but in North America, reindeer is the name generally given only to domesticated or semi-domesticated varieties of caribou, caribou being the French Canadian name for the wild reindeer of North America. In the Scandinavian countries of Europe and in the Asian regions of what we commonly call Russia, reindeer have been semi-domesticated for at least 2,000 and perhaps 7,000 years or more. This means that the domestication of caribou could actually predate the domestication of horses or cattle. In those regions, reindeer are still farmed for milk, meat, their hides and their antlers. They are also used as beasts of burden.
Some scientists are very specific about the differences between domesticated reindeer and wild caribou. They note that domesticated reindeer tend to be shorter, smaller and lighter in color than wild caribou and add that domesticated or semi-domesticated reindeer may need to be tended and/or driven to better grazing areas should food become scarce, while wild caribou herds migrate with the changing seasons, usually allowing vegetation in grazing areas to regrow.
To most, however, reindeer and caribou are one and the same - Rangifer tarandus, a native to the Arctic tundra and adjacent boreal forests. Their original range included northern Maine and parts of Minnesota. Small herds, numbering less than 30 animals, may still exist in the Rocky Mountain regions of Idaho, Montana and Wyoming, as well as parts of Washington state.
They are the only species in nature, deer or otherwise, in which both sexes grow antlers. A bull's antlers can grow to 4 feet in width and weigh more than 30 pounds. Antler length in females is usually only 9 to 20 inches. Males drop their antlers in winter. Pregnant females usually retain their antlers until after birthing.
In the spring, each pregnant cow gives birth to a single calf. Unlike many deer, reindeer calves are born without spots. At birth, they weigh between 10 and 20 pounds. Within an hour of their birth, they are able to walk. Within a day, they are able to outrun even the fastest humans.
In the wild, caribou reach sexual maturity when they are between 29 and 41 months old. Mating occurs in late September and October. For migrating herds, this means that mating occurs while traveling from summer to winter feeding grounds.
During the summer, caribou herds are able to find an abundance of grasses, sedges, browse and low-lying vegetation on which to feed. In winter months, they are able to lower their metabolic rate in order to reduce their food intake. Nonetheless, when food becomes scarce, they must migrate to open forest areas or find slopes where the wind keeps the snow off of the forage. Although they have large, concave hooves that allow them to dig easily in the snow, as conditions worsen, digging in ice and deep snow becomes more and more difficult. As a result, lichens growing on the bark of trees become the herds' primary winter food source. Because of this, one lichen variety that grows in Arctic tundra regions is commonly called reindeer moss. (It's interesting to note that the caribous' broad hooves also function like snowshoes, spreading to keep the animals from sinking when walking in soft snow and leaving a nearly circular print.)
As with other animals bred for agricultural purposes, different reindeer varieties have been developed to meet different human needs and environmental conditions. Some have been selectively bred for many generations while some attempts at domestication simply didn't work. Some domestic herds have escaped back into the wild only to become - well, not quite wild - wild herds, while other individual domesticated animals have wandered off with passing migrating herds never to be seen again.
With all of the breeding, crossbreeding and genetic manipulation that has taken place, you would think that anything can happen. Nonetheless, I am unaware of any variety of reindeer that are able to fly.
Please don't tell the children.
Human activity affecting
Exploration for oil, gas and minerals may be having a significant impact on caribou habitat. The cumulative potential impacts of development and production (disturbance, direct and indirect habitat loss, contamination of food and water) and other human land use activities along migration routes and in calving areas may profoundly influence the health of caribou and their ability to cope with stress and disturbance.
Global climate change may be having an even more significant impact. According to Eric Post, a Penn State associate professor of biology whose study, conducted in collaboration with Mads Forchhammer at the University of Aarhus in Denmark, was published in the July 12, 2008 issue of the Philosophical Transactions of the Royal Society of London, spring temperatures at their study site in West Greenland rose by more than 7 degrees Fahrenheit in just a few years.
In spring, as daylight increases, caribou move from wintering grounds to calving grounds, where newly emergent, highly nutritious food is plentiful. But those food plants respond to temperature, not day length, and as such are now peaking noticeably earlier. By the time pregnant female caribou arrive at their calving grounds, the plants they and their calves depend on have begun to decline in nutritional value. As a result, fewer calves are being born and more are dying. Post calls this "the first documentation of a developing trophic mismatch in a terrestrial mammal as a result of climatic warming."
What's more, reindeer follow carefully chosen migration routes year after year. But because of rising temperatures, rivers are thawing earlier and many that were once frozen over during migration are now full of rushing water that the migrating herds are forced to swim across. Many drown, while others are weakened to the point of exhaustion.
In a little more than three decades, caribou populations have decreased by 60 percent.