Home » Technology News » 2011 » December » December 24, 2011

Reindeer navigate better in snowy landscapes as they can see UV light

December 24, 2011 - Washington

Scientists claim that reindeer can see ultraviolet wavelengths, which may help them see contrasts in a mostly white environment, like snowy landscapes.

But they still do not know yet how the eyes of reindeer manage to let UV light in without causing damage or blindness.

The reindeer of Christmas myth must meet high expectations this time of the year, not just hauling heavy loads of gifts over long distances, but also helping navigate from the tundra to the rest of the world.

Even though most real reindeer never pull sleighs through snowy nights, new research suggests that their eyes would be far better suited to the task than Santa's are.

Unlike people, the study found, reindeer can see ultraviolet light, which probably allows them to detect food and predators in a mostly white environment.

The study makes reindeer the first large mammal known to have UV vision. And it raises questions about how animals that are highly specialized to their environments will adapt as their environments change.

"Reindeer are mammals and what we find may be related to humans," Discovery News quoted Karl-Arne Stokkan, an Arctic biologist at the University of Tromso in Norway as saying.

"In the view of potential climate change, we have also realized that reindeer may be an important 'signal-animal' because of their strong adaptation to an environment believed to suffer the biggest changes," Stokkan said.

Many animals are able to see or respond to ultraviolet light, including some birds, rodents, fish, bees and bats.

But UV light is invisible to the human eye and with enough exposure, can even cause damage.

Most dangerous are bright, snowy and icy conditions at high elevations or high latitudes, where lots of UV intensity and reflectivity can cause snow blindness in human eyes.

Since reindeer live in the Arctic, where levels of ultraviolet light are at their highest in proportion to other wavelengths, Stokkan and colleagues wondered if the animals might have evolved a way to deal with a world full of ultraviolet radiation.

UV vision might also help reindeer distinguish subtle contours in what might look like a flat landscape of snow, which would help them navigate safely.

The study has been published in the Journal of Experimental Biology.


Comment on this story