Have you ever wondered why Santa Claus chooses to harness reindeer to his sleigh? The answer takes us back to 1823, when the English poet Clement Clarke Moore wrote his famous poem ‘A Visit from St. Nicholas’ – later, it was even translated by Erich Kästner. And let’s be honest: the choice is a great one – reindeer are fascinating animals!
Reindeer have an amazing ability to cope with the stress and hustle and bustle that are ubiquitous at Christmas time: they can eat, digest and rest at the same time. Zurich researchers have discovered that reindeer fall into a kind of resting sleep while eating – a clever strategy for saving energy and time.
But that’s not all. Reindeer have another impressive feature: they can see UV light. In their Arctic home, where snow and ice reflect sunlight intensely, this ability gives them a decisive advantage. It not only helps them to detect predators more quickly, but also to locate food such as lichen, their most important source of nutrition, more easily. UV light makes lichen stand out against the white snow, enabling the animals to search for food more efficiently.
Another related feature, and a particular highlight, is their unique eye adaptation. The colour of reindeer eyes changes with the seasons! In summer, their eyes shimmer golden yellow, while in winter, during the dark polar night, they take on a deep blue colour. They owe this colour change to a layer in the eye, known as the tapetum lucidum. This layer reflects light back through the retina, increasing light sensitivity. In winter, this layer becomes denser, creating the blue colour and increasing UV sensitivity. In summer, on the other hand, the golden eye colour protects the animals from overexcitement caused by strong sunlight.
Incidentally, reindeer are also important for climate protection. By compacting the snow cover through their grazing, they help to keep the underlying permafrost cool. This prevents the release of huge amounts of greenhouse gases that could further fuel climate change. Without reindeer, the consequences of climate change in the Arctic regions would probably be even more dramatic.
With all these impressive abilities, reindeer have more than earned a place in the spotlight of the Christmas season (and a very special entry in the Alaska Department of Fish and Game). So, here’s to Rudolph and his reindeer colleagues!