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Fun Facts about Reindeer and Caribou


CVM’s Office of Minor Use and Minor Species Animal Drug Development (OMUMS for short) works hard to make sure safe and effective drugs are available for minor species, like Santa’s reindeer (or are they caribou?).

  • Reindeer and caribou are the same animal (Rangifer tarandus) and are a member of the deer family. In Europe, they are called reindeer. In North America, the animals are called caribou if they are wild and reindeer if they are domesticated.
  • Both male and female reindeer grow antlers, while in most other deer species, only the males have antlers. Compared to their body size, reindeer have the largest and heaviest antlers of all living deer species. A male’s antlers can be up to 51 inches long, and a female’s antlers can reach 20 inches.
  • Unlike horns which are never shed, antlers fall off and grow back larger each year. Male reindeer begin to grow antlers in February and female reindeer in May. Both sexes finish growing their antlers at the same time but shed them at different times of the year. Typically, males drop their antlers in the late fall, leaving them without antlers until the following spring, while females keep their antlers through the winter until their calves are born in the spring.
  • Reindeer are covered in hair from their nose to the bottom of their feet (hooves). The hairy hooves may look funny, but they give reindeer a good grip when walking on frozen ground, ice, mud, and snow.
  • Reindeer are the only deer species to have hair completely covering their nose. Their specialized nose helps to warm incoming cold air before it enters their lungs, and it’s also an excellent sniffer. Their good sense of smell helps the reindeer find food hidden under snow, locate danger, and recognize direction. Reindeer mainly travel into the wind so they can pick up scents.
  • Reindeer eat mosses, herbs, ferns, grasses, and the shoots and leaves of shrubs and trees, especially willow and birch. In winter, they make do with lichen (also called reindeer moss) and fungi, scraping the snow away with their hooves to get it. An average adult reindeer eats 9 to 18 pounds of vegetation a day.
  • Reindeer travel, feed, and rest together throughout the day in herds of 10 to a few hundred. In spring, they may form super-herds of 50,000 to 500,000 animals. The herds generally follow food sources, traveling south up to 1,000 miles when food is hard to find in winter.
  • Reindeer are the only deer species to be widely domesticated. They are used as draft animals to pull heavy loads and farmed for their milk, meat, and hides.
  • The antiparasitic drug ivermectin is FDA-approved to treat and control warbles in reindeer. Warbles is a parasitic infection caused by the reindeer warble fly. The fly’s larvae can penetrate the reindeers’ skin, causing harm to the milk, meat, and hides of domesticated herds. The larvae can also cause disease in people.
  • Santa’s reindeer were first mentioned in 1821 when New York printer William Gilley published a 16-page booklet titled A New Year’s Present to the Little Ones from Five to Twelve, Part III by an anonymous author:

    Old Santeclaus with much delight
    His reindeer drives this frosty night.
    O'er chimneytops, and tracks of snow,
    To bring his yearly gifts to you.

    Two years later, in 1823, the Troy Sentinel published the poem A Visit from St. Nicholas, commonly known as ‘Twas the Night Before Christmas. The poem featured eight flying reindeer pulling Santa’s sleigh, and for the first time, they are identified by name. (Quiz Question 1: Can you name all eight of Santa’s reindeer?)

    Rudolph the Red-Nosed Reindeer began guiding Santa’s sleigh in 1939, when Robert L. May wrote the story of “the most famous reindeer of all” as a Christmas coloring book for his employer, the department store Montgomery Ward. The company gave away the coloring books as holiday gifts to children to entice their parents to visit and shop at the store. (Quiz Question 2: What two names did May consider for his red-nosed reindeer before settling on Rudolph?)

    In 1948, May’s brother-in-law Johnny Marks made the story into a song. It was featured in a cartoon shown in movie theaters, but wasn’t released as a stand-alone recording until 1949 when “The Singing Cowboy” Gene Autry recorded the song and its popularity soared. Rudolph the Red-Nosed Reindeer is one of the biggest-selling Christmas songs of all time. (Quiz Question 3: Is Rudolph the Red-Nosed Reindeer a male or female?)

Quiz Answers:

  1. Dasher, Dancer, Prancer, Vixen, Comet, Cupid, Donner, and Blitzen.
  2. Rollo and Reginald.
  3. Rudolph the Red-Nosed Reindeer is most likely a female to have those antlers on Christmas Eve!


San Diego Zoo, Reindeer (Caribou)
Altogether Christmas, The History of Santa’s Reindeer
Altogether Christmas, The History of Rudolph the Red-Nosed Reindeer

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