This video was produced by the Royal Institution as part of their Ri Advent Calendar series on chromosomes, which is supported by BBSRC. Each day in December 2013, scientists reveal stories behind their favourite chromosomes.
Researchers have discovered the eyes of Arctic reindeer change colour through the seasons from gold to blue, adapting to extreme changes of light levels in their environment and helping detect predators. The BBSRC-funded team from UCL (University College London), and the University of Tromsø, Norway, showed that the colour change helps reindeer to see better in the continuous daylight of summer and continuous darkness of Arctic winters, by changing the sensitivity of the retina to light.
Nature, as the great poet Tennyson reminded us, is a violent place, or "red in tooth and claw", as he put it. One of the mechanisms animals use to avoid a bloody end is camouflage – blending in with the background – to avoid predators.