Reindeers’ Eyes Change Colour

Canadian (November 2, 2013). Scientists have discovered a strange twist with the eye colour of Artic Reindeer. They found that the colour of their eyes change, depending upon the season. They believe that the reason for this is to help the reindeer adapt to the low light conditions in the winter and also to help them recognizing possible predators and increasing foraging opportunities.

The research was completed by a team from University College London and the University of Tromso, Norway. Many vertebrate animals, like the Artic reindeer, have a layer of tissue in the eye called the tapeturn lucidum. It reflects light back through the retina and this gives them superior night vision. By changing the eye colour, it reflects different wavelengths of light. During the summer, the reindeer’s eyes turn gold, like other animals. This reflects more light through to the retina. During the winter their eyes change to a deep blue. This reflects less light out of the eye. This process increases the sensitivity of the retina during the dark winter months.

“This is the first time a colour change of this kind has been shown in mammals. By changing the colour of the TL in the eye reindeer have flexibility to cope better with the extreme differences between light levels in their habitat between seasons. This gives them an advantage when it comes to spotting predators, which could save their lives” said Professor Glen Jeffery from UCL.

Interestingly, Professor Jeffery and his associates had found that Artic reindeer can see ultraviolet light. While we can’t see ultraviolet light, Artic reindeer can and there are high levels of this in the Artic.

As a side note: If you see Santa around Christmas, you will note that Rudolf and the other reindeer have deep blue eyes and now you know why.

Wayne Sheridan for Canadian Angling