Featured Research

from universities, journals, and other organizations

Bright eyes: Reindeers' eyes change from blue to gold with Arctic seasons

Date:
October 29, 2013
Source:
Biotechnology and Biological Sciences Research Council
Summary:
Researchers have discovered the eyes of Arctic reindeer change color through the seasons from gold to blue, adapting to extreme changes of light levels in their environment and helping detect predators. It is the first such color change observed in mammals.

The difference in eye colour between summer and winter is clear in this picture.
Credit: Glen Jeffery

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 Biotechnology and Biological Sciences Research Council (BBSRC) funded team from UCL (University College London), and the University of Tromsψ, 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.

Arctic reindeer, like many animals, have a layer of tissue in the eye called the tapetum lucidum (TL) which lies behind the retina and reflects light back through it to enhance night vision.

By changing its colour the TL reflects different wavelengths of light.

In the bright light of summer the TL in Arctic reindeer is gold, similar to many other mammals, which reflects most light back directly through the retina.

However by winter it has changed to a deep blue which reflects less light out of the eye.

This change scatters more light through photoreceptors at the back of the eye, increasing the sensitivity of the retina in response to the limited winter light

The team believes this would be an advantage in the prolonged murk of winter, allowing reindeer to more easily detect moving predators and forage.

Lead researcher Professor Glen Jeffery from UCL, said: "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."

The colour change may be caused by pressure within the eyes. In winter pressure in the reindeers' eyes is increased, probably caused by permanent pupil dilation, which prevents fluid in the eyeball from draining naturally. This compresses the TL, reducing the space between collagen in the tissue and thus reflecting the shorter wavelengths of the blue light common in Arctic winters.

Previous work from Professor Jeffery and Norwegian colleagues from Tromso had shown that Arctic reindeer eyes can also see ultraviolet, which is abundant in Arctic light but invisible to humans, and that they use this to find food and see predators.

The blue reflection from the winter eye is likely to favour ultra-violet sensitivity.


Story Source:

The above story is based on materials provided by Biotechnology and Biological Sciences Research Council. Note: Materials may be edited for content and length.


Journal Reference:

  1. K.-A. Stokkan, L. Folkow, J. Dukes, M. Neveu, C. Hogg, S. Siefken, S. C. Dakin, G. Jeffery. Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer. Proceedings of the Royal Society B: Biological Sciences, 2013; 280 (1773): 20132451 DOI: 10.1098/rspb.2013.2451

Cite This Page:

Biotechnology and Biological Sciences Research Council. "Bright eyes: Reindeers' eyes change from blue to gold with Arctic seasons." ScienceDaily. ScienceDaily, 29 October 2013. <www.sciencedaily.com/releases/2013/10/131029220802.htm>.
Biotechnology and Biological Sciences Research Council. (2013, October 29). Bright eyes: Reindeers' eyes change from blue to gold with Arctic seasons. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2013/10/131029220802.htm
Biotechnology and Biological Sciences Research Council. "Bright eyes: Reindeers' eyes change from blue to gold with Arctic seasons." ScienceDaily. www.sciencedaily.com/releases/2013/10/131029220802.htm (accessed July 29, 2014).

Share This




More Earth & Climate News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Newsy (July 28, 2014) — The asteroid that killed the dinosaurs struck at the worst time for them. A new study says that if it hit earlier or later, they might've survived. Video provided by Newsy
Powered by NewsLook.com
The Carbon Trap: US Exports Global Warming

The Carbon Trap: US Exports Global Warming

AP (July 28, 2014) — AP Investigation: As the Obama administration weans the country off dirty fuels, energy companies are ramping-up overseas coal exports at a heavy price. (July 28) Video provided by AP
Powered by NewsLook.com
Raw: Sea Turtle Hatchlings Emerge from Nest

Raw: Sea Turtle Hatchlings Emerge from Nest

AP (July 27, 2014) — A live-streaming webcam catches loggerhead sea turtle hatchlings emerging from a nest in the Florida Keys. (July 27) Video provided by AP
Powered by NewsLook.com
Trees Could Save More Than 850 Lives Each Year

Trees Could Save More Than 850 Lives Each Year

Newsy (July 27, 2014) — A national study conducted by the USDA Forest Service found that trees collectively save more than 850 lives on an annual basis. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins