91�ȱ�

After a photo of an adorable white reindeer went viral this week, other people have shared their snaps of the animals.

Dr Nicholas Tyler, from the Centre for Saami Studies at the University of Tromso in Norway, told the 91�ȱ� that white reindeer are rare.

However, he adds that they are "highly conspicuous", especially in the summer months, which may go some way to explain why people are able to get so many great photographs of them.

While some people refer to these animals as "albino",

As can be seen in these photos, the reindeer have white fur but do not lack pigment in their eyes.

Glen Jeffery, from the Institute of Ophthalmology at University College London, explains that the production of pigment in the skin and eyes are controlled independently.

This means that the animals do not suffer from the visual difficulties associated with albinism.

"For animals where pigment generation fails in the eye, the world becomes terribly bright... as light bounces around in the eye because it's not absorbed by pigment."

Jerry Haigh is a professor of Large Animal Clinical Sciences at the University of Saskatchewan, Canada. He has spent time studying the reindeer herds of Northern Mongolia.

He says that white reindeer are "quite common" among the herds cared for by the nomadic Dukha community.

Kristen Jayne took this photo of a group of reindeer while travelling from Jokkmokk to Ostersund in Sweden, in 2017.

On his first trip to Norway, Kevin Barta spotted this white reindeer which was part of a larger group.

"The reindeer herd saw us and started to run," he told the 91�ȱ�, "the white reindeer came close so I got some good photos."

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