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Reindeer Clocks

December 23, 2016

Most mammals have internal clocks that regulate their daily cycles, but not reindeer.



Reindeer clocks. I’m Bob Hirshon and this is Science Update.

Don’t ask Rudolph what time of day Santa’s coming to town – he won’t have a clue. That’s because reindeer lack circadian rhythms: internal clocks that control the daily activity of just about every other mammal. This according to University of Manchester neuroendocrinologist Andrew Loudon. His team found that the genes that normally control circadian rhythms are switched off in reindeer.

ANDREW LOUDON (University of Manchester):

So if you asked a reindeer what time of day it is, it would probably have a bemused look on its face. But if you asked it what time of year it was, it could probably tell you with greater precision than probably any other animal on the planet.


Loudon says reindeer don’t have much need for clo cks in the high Arctic, which is dark nearly 24 hours a day in the winter. But they do need accurate annual clocks so they can start breeding at the best time. I’m Bob Hirshon, for AAAS, the science society.

Story by Susanne Bard