Santa’s team of reindeer helpers has inspired Christmas songs, Hollywood movies, and an off-Broadway musical. But unlike the other magical creatures that populate our screens and stages, Santa’s reindeer have a real-world counterpart with a population that numbers in the millions.
Armed with thick fur and tremendous antlers, these regular, non-flying reindeer have a circumpolar distribution, meaning they live on every continent with land near the North Pole.
So, whether you’re a Christmas nerd or Arctic animal buff, here are six fun facts about reindeer to share with friends and family this holiday season.
1. Reindeer Became a Symbol of Christmas in the 1820s
Though the term “reindeer” is typically reserved for populations in northern Europe and Asia, the North American caribou is technically the same species: Rangifer tarandus.
What Is the Legend of the Reindeer?
Whether they’re labeled as reindeer or caribou, however, the legend of Santa’s sleigh team seems to have emerged from a combination of Norse mythology, Dutch Christmas tales, and the real-world practices of nomadic reindeer herders in northern Scandinavia.
Still, it wasn’t until 1823 that American author and poet Clement Clarke Moore cemented Santa’s reindeer retinue in the modern Christmas canon with the poem, “A Visit from St. Nicholas.”
Famous for its initial line (“‘Twas the night before Christmas”), the poem painted an enduring picture of Santa’s team of reindeer and toy-laden sleigh:
“When what to my wondering eyes did appear,
But a miniature sleigh and eight tiny rein-deer,
With a little old driver so lively and quick,
I knew in a moment he must be St. Nick.”
2. Reindeer See Through The Dark With Ultraviolet Sight
Many reindeer live in the far north, in places where there’s little to no daylight during the winter months. In Utqiagvik, Alaska, the northernmost community in the U.S., for instance, the sun sets in November and doesn’t rise again until January. (In that stretch of “polar night,” you’d definitely need Rudolph’s red nose to see.)
How Have Reindeer Evolved?
But while humans are stuck in the dark, reindeer have evolved to be able to see in the mid-winter twilight. In fact, while the shortest wavelength of light that humans can see is around 380 nanometers, reindeer can see light in the “ultraviolet” range, with wavelengths as short as 320 nanometers. These waves are far beyond human’s “visible spectrum.”
Reindeer may have evolved their ultraviolet-sensitive eyes to hunt down lichens — hardy, composite organisms that are composed of fungus and algae and provide essential winter nutrients in an otherwise barren landscape. In the winter, the lichens absorb ultraviolet light, while the snow reflects it. This means that, to a hungry reindeer, the lichens look like blobs of black in a sea of white, even when they are buried beneath the snow.
Read More: The 5 Senses Animals Have That Humans Don't
3. Reindeer Have No Circadian Rhythm
While most animals have an internal clock that tells them when to be active and when to inactive, Arctic reindeer do not.
How Do Reindeer Know When to Sleep?
Studies have shown that the genes that govern the circadian clock in other deer are inactive in reindeer. Instead, reindeer rely entirely on signals of light and dark to tell them when to wake and when to sleep. The reason why isn’t entirely clear. Yet some researchers have suggested that it might help the animals deal with the perpetually dark Arctic winter, during which they bounce unpredictably between bursts of activity and rest.
A second explanation is mysteriously absent from the scientific literature: Perhaps the lack of an internal clock is what allows Santa’s reindeer to stay up all night delivering presents.
Read More: These Animals Get Creative To Get Some Sleep
4. Reindeer Have the Longest Migration of Any Land Animal
Reindeer, or North American caribou more specifically, hold the title for the longest seasonal migration of any terrestrial animal.
How Do Reindeer Migrate?
Each year, the Bathurst caribou herd migrates more than 800 miles through the frontiers of Canada, from Northern Saskatchewan to their calving grounds in the Northwest Territories. These intrepid ungulates make their first trek when they are less than a year old.
Do Caibou Have Predators?
The title of second-longest migration goes to the gray wolf, the caribou’s predator. The wolves follow the herd for much of the year. But, while the wolves don’t follow the caribou all the way North to the Bathurst Peninsula in Nunavut, research has shown that the wolves actually walk more total miles than the caribou in a given year. While the steadfast caribou plod along their migration route, the wolves walk a haphazard and circuitous path in search of prey.
5. Human-Reindeer Relations Trace Back to Long Before Santa
The Sámi people of northern Scandinavia have lived alongside reindeer for more than two thousand years. In ancient times, they were nomads, who hunted and fished for their food. But since the 1600s, they have herded reindeer between the animal’s winter and summer feeding grounds. Each year, in the late fall, the Sámi harvest a portion of the herd. Then the meat is stored and eaten throughout the winter.
Who Herded Ancient Reindeer?
The Sámi are just one of many Arctic Indigenous peoples that rely on reindeer for sustenance. Caribou are an important food source for Indigenous tribes in Alaska and Northern Canada, too. The Ahiarmiut, an Inuit tribe indigenous to present-day Nunavut, followed caribou herds year-round before they were forced out of their homeland by the Canadian government in the 1950s. Many Inuit tribes, such as the Iñupiat of Northern Alaska, still rely on caribou meat for sustenance.
6. Reindeer Are on the Decline
Though the species still numbers in the millions, its population is decreasing due to habitat destruction and climate change.
Are Reindeer Endangered?
No, reindeer are not endangered, but In 2016, the International Union for Conservation (IUCN) designated Rangifer tarandus as “vulnerable” on its Red List of Threatened Species.
The Bathurst caribou herd, the same one that holds the title for the longest terrestrial migration, has lost more than 98 percent of its population since the 1980s. Once half a million strong, the herd has recently declined to less than 7,000 animals.
For now, reindeer are still plentiful across much of their range, but they face an uncertain future.
Frequently Asked Questions About Reindeer
What is a Reindeer?
Reindeer, scientifically known as Rangifer tarandus, are a species of deer native to Arctic, sub-Arctic, tundra, boreal, and mountainous regions of northern Europe, Siberia, and North America. They are known for their distinctive antlers, which both males and females grow.
Are Reindeer Real?
Yes, reindeer are real animals. They are often associated with holiday folklore and Santa Claus, but they are indeed a real species.
What Do Reindeer Eat?
Reindeer primarily feed on lichens in the winter, known as reindeer moss. They also eat the leaves of willows and birches, as well as sedges and grasses. Their diet can vary depending on the season and availability of food sources.
Are Caribou and Reindeer the Same?
Caribou and reindeer belong to the same species (Rangifer tarandus) but are considered different subspecies. In Europe, they are all called reindeer, while in North America, the wild populations are known as caribou, and the domesticated ones are called reindeer.
How Long Do Reindeer Live?
In the wild, reindeer can live up to about 15 to 20 years. However, their lifespan can vary depending on environmental conditions, predation, and human activities.