A man dressed as Santa Claus rides his sleigh as he prepares for Christmas on the Arctic Circle in Rovaniemi, northern Finland.
A man dressed as Santa Claus rides his sleigh as he prepares for Christmas on the Arctic Circle in Rovaniemi, northern Finland. REUTERS

The red nose of Rudolph, the lead fictional reindeer pulling Santa Claus's sleigh on Christmas Eve and showing light on the path through its luminous nose, has interested researchers for long.

Now scientists say that the red nose of Rudolph may have more to it than just being a Christmas folklore feature.

According to a team of Swedish researchers, a reindeer's nose appears red in extremely cold conditions when increased blood flow happens to stop the animal from freezing.

Scientists at Lund University have captured the phenomenon with a thermographic camera. The thermal images show various body areas of a reindeer, including the nose, appearing red in freezing cold.

"When reindeer are feeding, their mules are exposed to very low temperatures as they look for food under the snow. They need to maintain sensitivity in order to know what they're actually eating", Ronald Kröger, Professor of Functional Zoology at Lund University, said in a statement.

"This means reindeer pump warm blood into the nose in cold weather, possibly creating a reddish "glow," he explained.

Scientists took the thermal images of a reindeer at the Zoo of Nordic Animals in Sweden, the world's largest zoo for Nordic animals.

"The thermographic cameras show the heat coming from their body. The eyes and the mule are lighter and warmer than the rest of the body," Kröger added.

Like reindeer, other mammals including humans also use their nose tip to obtain sensory information about weather conditions.

An observation study by Dutch and Norwegian researchers in 2012 concluded that the intrinsic physiological properties of "Rudolph's legendary luminous red nose help to protect it from freezing during sleigh rides and to regulate the temperature of the reindeer's brain, factors essential for flying reindeer pulling Santa Claus's sleigh under extreme temperatures".