Arctic reindeer can detect ultraviolet wavelengths

Excepts from an article posted at the BBC:

Arctic reindeer can see beyond the "visible" light spectrum into the ultra-violet region, according to new research by an international team. They say tests on reindeer showed that the animal does respond to UV stimuli, unlike humans.

The ability might enable them to pick out food and predators in the "UV-rich" Arctic atmosphere, and to retain visibility in low light...

Lichen, on which the animal feeds, would appear black to reindeer eyes, they say, because it absorbs UV light. The animal's traditional predator, wolves, would also appear darker against the snow, as their fur absorbs UV light. Urine in the snow would also be more discernable in UV vision, which might alert reindeer to the scent of predators or other reindeer...

Professor Lars Chittka of Queen Mary University London, who has explored the UV capabilities of bees, said the study showed what we call the "visible" spectrum did not apply to most of the animal kingdom. "It's further evidence that UV sensitivity across animals is the rule rather than the exception, and that humans and some other mammals are actually a minority in not having UV sensitivity," he said.

The research has been published in The Journal of Experimental Biology (which also has an article showing that cockroaches employ a "tripod" gait, keeping three legs in contact with the surface while moving.