A study released just in time for Santa’s nocturnal sleigh ride suggests his reindeer, at least, won’t be tired.That’s because the day/night cycle at Arctic latitudes is so irregular that reindeer have long ago disposed of all but the faintest of the circadian clocks that humans and other animals are saddled with, according to a Norwegian study.The bottom line: “On his round-the-globe trip on Christmas Eve, Santa would have to work through his ‘inner night,’ while Rudolph would feel no such constraints,” said lead researcher Karl-Arne Stokkan, a professor in the department of Arctic Biology at the University of Tromsø.His team published its findings in the Dec. 22 issue of Nature.
