… and the truth about Santa’s reindeer
On December 24th, children around the world will be avid wildlife viewers as they lift their eyes to the night sky, searching for signs of flying reindeer pulling a magic sleigh filled with toys.
“On Dasher and Dancer, Prancer and Blitzen. On Comet and Cupid, Donner and Blitzen!” Don’t forget our nasally-maligned most famous reindeer of all: Rudolf. In old story books and cartoons, Christmas cards and decorations, these reindeer are all depicted with antlers as they whizz around the world in 24 hours. And since this phenomenon is entirely scientifically accurate, the presence of antlers has made us inclined to think of these reindeer as male. But that is an incorrect assumption!
For all intents and purposes, reindeer and caribou are the same thing: Rangifer tarandus. This circumpolar species is found across the North but has regional differences such as size, colour, migration habits, food preferences and herd size. With so much variation, scientists are constantly debating whether the species should be divided into sub-populations or a different species entirely. If that were to happen, “Flying reindeer” or Rangifer tarandus aeronauticus, would certainly receive its own classification.
Caribou are one of the Yukon’s nine species of ungulate. In addition to having hooves, ungulates in the Yukon have either horns or antlers. People often use the terms interchangeably, but they are quite different appendages. Horns have a bone core with a sheath of keratin (the same material as your fingernails) and grow continuously throughout an animal’s life. Both males and females have horns, though male horns are often larger and more robust. Female horns are more slender, used for defence rather than open combat.
By contrast, antlers on Yukon ungulates are branched and are made entirely of bone. They grow each year, usually bigger than the last, and then fall off after the rut in the fall. Unlike with horns, only males grow antlers, except for caribou. Both male and female caribou (reindeer) grow antlers; however, female antlers are much smaller than the elaborate racks of males.
Ungulates use their horns or antlers for similar things. Their size is a display of power and can decide the social order. They will also use them in defence against predators, sometimes delivering lethal wounds. Most famously, they are used to challenge other males for dominance during the mating season. Males expend huge amounts of energy during the rut and after they have served their purpose, antlers are shed as the first snow flies.
Female caribou, however, don’t drop their antlers in the late fall after the rut. They will keep their antlers well into the winter and continue to use them as defence against predators. Females will typically shed their antlers in the spring around calving season.
This season, as you train your eyes to the sky and think of magic reindeer flying around on Christmas Eve, remember that male reindeer have already dropped their antlers by December 24th. So those reindeer doing all the heavy lifting are actually female.
[call out box]
Can’t remember the difference between horns and antlers? Here’s a small ditty that will become your new favourite ear-worm:
(To the tune of “Frère Jacques”)
Horns and antlers, horns and antlers,
On your head, on your head.
Antlers they will fall off, every year they fall off;
Horns stay on, ‘til you’re gone.
