Rudolph may be the most famous red-nosed reindeer of all time, but there are others. A small amount of reindeer, Rangifer tarandus - native to the Arctic regions in Alaska, Canada, Greenland, Russia, and Scandinavia - do have noses with a distinctively red coloring. In fact, a study published in BMJ, delves into the scientific reasons that this phenomenon exists.
Using a handheld microscope, researchers from the Netherlands and Norway examined the noses of five healthy volunteers and two adult reindeer from Tromsø, Norway, which is close to the North Pole. The researchers looked at the tiny blood cells, called micro-vessels, located in the nose. They are vital in both humans and reindeer for delivering oxygen, controlling inflammation, and regulating temperature, as well as delivering medicine, but their function has rarely been assessed in scientific studies.
Compared to the healthy human volunteers, the reindeer's noses had 25 percent more blood density. That means that they had a much richer concentration of red blood vessels in their noses than the healthy human participants had. They also have a high density of mucous glands, which help protect the nose during changing weather conditions, act as a barrier, and transport fluid.
Furthermore, thermal imaging revealed that reindeers - even outside of the arctic region - really do have red noses. While exercising, their noses can reach 75 degrees Fahrenheit, warm for reindeer. This finding indicates that the function of these blood vessels is to regulate body temperature.
The publication of the study is simply the latest in BMJ's annual Christmas tradition, in which the journal publishes lighter, quirkier fare than they normally do. Previous issues have debunked urban legends (in Netherlands, a popular myth states that people can become drunk by soaking their feet with alcohol; in a study that the Mythbusters would be proud of, that was found not to be true) and providing historical background, like Dr. Charles Fletcher's description of how he found ways to test penicillin.