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Reindeer's Eyes Change Color, Shadowing Rudolph's Red Nose – New Research Podcast

Reindeer may not have a red nose, but these cold-weather creatures have developed the power to vary their eye color to assist them thrive at midnight, northern winters. In this Discovery episode, we talk. Glenn Jeffreyprofessor of neuroscience on the Institute of Ophthalmology at UCL (University College London) within the UK about what makes reindeer eyes truly unique within the animal kingdom.

Most people have seen the golden, glowing eyes of a cat, raccoon or other nocturnal animal while driving at night. The a part of the attention which produces that golden reflection is, as Geoffrey explains, “a mirror called by many animals the tapetum lucidum.” A tapetum helps animals see higher at midnight by bouncing light from the back of the attention through the retina a second time. In most mammals, the tapetum is a “standard gold”, as Jeffrey describes the colour, and this color doesn't change.

Many animals' eyes glow at midnight due to a reflective layer called the tapetum lucidum, which is normally gold.
Bol Hoover/Wikimedia Commons

One day, Jeffrey received a blue box within the mail. In it were two jars stuffed with reindeer eyes from a slaughterhouse in Norway. One jar was labeled summer and one was labeled winter.

“I opened the first summer and I thought, 'I'm wasting my time here,'” says Jeffrey. He saw golden eyes, exactly what he expected.

“But then we opened the other eyes, and then there was a shock, because Winter's eyes were blue.” “I've never seen anything like it in my life.”

Geoffrey and his colleagues spent years studying the biology of reindeer eyes and the environment created for them – the dull, blue months of the Arctic winter. What they found is a surprising little bit of evolution that has given reindeer among the most interesting eyes on Earth. Watch this Discovery episode of the confer with hear how Jeffrey and his colleagues study reindeer eyes, why winter eyes are a singular color, and the way light pollution can alter this subtle adaptation. Listen to the sod.

The episode was written and produced by Katie Flood with Gemma Ware and hosted by Dan Merino. Eloise Stevens does our sound design, and our theme music is by Neeta Searle.

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