Seven Facts about the World’s Most Festive Ungulate

With a visit from Santa just around the corner, a team of charismatic megafanua will soon be tramping about on rooftops worldwide. Most people who celebrate Christmas are familiar with Santa’s team of nine reindeer. These beautiful animals have a myriad of interesting characteristics. Here are seven facts that will shock and amaze your Great Aunt Ethel while the Christmas pudding is singing in the copper.

1. Male reindeer (bucks) have much louder calls than females, especially during rutting season. When bellowing is necessary, they inflate a laryngeal sac just under the skin of their throats. This structure is dimorphic measuring an average 100 cm³ in volume in females, to an impressive 3000-4000 cm³ in males.

Photo by Dean Biggins: Wikimedia Commons

2. A recent study discovered that reindeer’s eyes colour changes to match the season. Their eyes are golden in the summer, and blue in the winter. The colour change is not the iris itself, but on the ‘tapetum lucidum’ – the surface behind the central retina. When the tapetum is blue, less light is reflected out of the eye compared to when the tapetum is gold. Although this means the reindeer sees less clearly, its eyes are 1,000 times more sensitive to light when the tapetum is blue. When reindeer are living in winter conditions of pervasive darkness, this is surely an advantage!

3. Reindeer are the only type of deer known where females and males both possess antlers. Antlers are shed, and regrown annually. In a small number of populations, females lack antlers.

4. Certain populations of reindeer hold the record for the longest migration of any terrestrial animal. When snowfall begins, reindeer migrate up to 2,500 kilometers south to have better access to lichens – a dietary staple.

5. Reindeer live in a somewhat association with Her Majesty Queen Elizabeth II. One is featured on the tails-side of the Canadian 25 cent piece.

Heads or Tails? Reindeer or Royalty?

6. The reindeer (also known as caribou in North America) are big and warm – making them prone to attack by a complex of blood-feeding flies. These insects are so abundant, it is thought that reindeer may lose up to a litre of blood for each week spent living on the tundra!

7. Reindeer have also had their spot in times of war. During World War II, the Soviet Army used reindeer to transport ammunition, food, and mail hundreds of kilometers between Murmansk and the Karelian Front.

Wishing you all a merry Christmas!

References:

Frey, R., Gebler, A., Fritsch, G., Nygrén, K., & Weissengruber, G. E. (2007). Nordic rattle: the hoarse vocalization and the inflatable laryngeal air sac of reindeer (Rangifer tarandus). Journal of anatomy, 210(2), 131-159.

Hoare, B. (2009). Animal Migration. London: Natural History Museum.

Smits SL, Schapendonk CME, van Leeuwen M, Kuiken T, Bodewes R, et al. (2013) Identification and Characterization of Two Novel Viruses in Ocular Infections in Reindeer. PLoS ONE 8(7)