Scientific Benefits Of Rudolph's Glowing Red Nose And Arctic Reindeer Eyesight
We all know the story of how Rudolph the Red-Nosed Reindeer saved Christmas. But have you ever wondered how a bright red nose helped Rudolph guide Santa and his sleigh on a foggy winter night? Maybe it wasn't due to just his nose? In a recent study, researchers from Dartmouth College examined the unique eyes and vision of Arctic reindeer to find out.
Unlike humans and most mammals, Arctic reindeer (Rangifer tarandus tarandus) can see ultraviolet light. Although it is rare, this trait comes in handy when reindeer have to guide Santa around the world mid-winter when the sun is low on the horizon and much of the light is a dim blueish to ultraviolet color. Furthermore, the reflective tissue (tapetum lucidum) in reindeer eyes adapts to winter by changing to a deep blue color, which in turn helps the animals see blue light, according to a news release.
However, the only problem with being able to see purples and blues really well is that these colors are practically invisible in fog, which makes it increasingly difficult for reindeer to see, let alone fly.
That's where Rudolph's glowing red nose comes in. Red light works best in fog and would therefore be the perfect fog light to guide his fellow reindeer. Given that Rudolph's nose is often compared to the deep redness of holly berries, researchers created a reflectance spectrum, which they used to estimate the color of Rudolph's nose, and concluded that it most likely produces light with a spectral peak of about 700 nm, the maximum wavelength of light reflected by holly berries.
This, researchers say, is possibly the maximum redness that mammals are able to see and would therefore explain why Rudolph was able to see past the fog on Christmas Eve.
Having a luminescent nose has its disadvantages, too. Reindeer noses are extremely vascular, which enables them to vent body heat – so having a glowing nose could cause excessive heat loss and put Rudolph at risk of hypothermia, researchers say.
"It is therefore imperative for children to provide high-calorie foods to help Rudolph replenish his energetic reserves on Christmas Eve," Nathaniel J. Dominy, lead author and professor of Anthropology at Dartmouth, added.
Their findings were recently published in the journal Frontiers for Young Minds.
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