RENEE MONTAGNE, HOST:
Good morning. I'm Renee Montagne. Everyone knows one foggy Christmas Eve, Santa Claus had a red nose reindeer guide his sleigh. And here's some science behind Rudolph getting that gig. Dartmouth researcher Nathaniel Dominy points out reindeer can see UV or blue light, which helps them see at night. But fog obscures the blue light. And to Rudolph, red light travels through fog quickly, and with that nose, the rest is history. It's MORNING EDITION. Transcript provided by NPR, Copyright NPR.