Not every reindeer has a red nose. After all, that’s part of what makes Rudolph so special—and he’s not alone.
Some Reindeer, Rangifer tarandus, living in the far northern Arctic Regions of the world like Canada, Greenland, Scandinavia, and Russia, share this rostral rosy hue.
A 2012 study published in the BMJ-British Medical Journal revealed why, and it may be unsettling for some.
The reason is, well, blood. Lots of it! Reindeer noses are densely packed with blood vessels that provide a rich supply of red blood cells — a process called nasal microcirculation. As you may be familiar, red blood cells play a key role in transporting oxygen in our bodies. This extra nasal blood supply means there’s also increased oxygen. This combination helps to control inflammation and regulate body temperature — something that’s surely helpful in such extreme environments.
So, that answers one question, but it raises another. How exactly did scientists figure this out?
Treadmills and cameras.
Researchers selected two reindeer and five human volunteers. First, they used a hand-held video microscope that intriguingly allowed them to watch the nasal blood flow in real-time. Careful observation showed that the reindeer had an average of 25% more blood vessels in their noses than the humans.
Afterward, they put the reindeer on a treadmill. Using an infrared camera that detects heat, they were able to measure where the body was shedding the most heat. The nose, and surprisingly the hind legs, were the clear standouts.
Just like the giant ears of an elephant, all of this extra blood flow helps to bring blood close to the surface to release heat from inside the reindeer’s body that’s otherwise trapped.
Interestingly enough, that’s the exact kind of adaptation that would give Rudolph the leg up in almost any kind of Reindeer games.