Imagine that it has been freezing cold in your home for weeks, that you can hardly feel your legs and arms any more, that you have only been eating dried beans for days and that burglars are constantly trying to gain access to your house.
This or similar is how ungulates like the red deer must feel in their winter habitat when ski tourers, snowshoe trekkers or freeriders invade. From November to March, the red deer’s diet is more meagre than dried beans. In extreme cases, this leaves only lichens from tree trunks and branches as food.
To survive the snowy and cold winters, the deer is physiologically adapted in an incredible way. In concrete terms, this means saving energy at all levels: The deer can actually reduce the blood flow in their extremities. The body temperature there drops sharply for up to 9 hours. This allows the animals to save about 17% of their energy and still stay nice and warm in their core. The disadvantage of this “saving measure”: Sudden sprints become difficult. To escape, the entire metabolism has to be ramped up again from this winter torpor. This costs the emaciated red deer a lot of valuable energy. Disturbances by humans in the winter habitat of wild animals can therefore be fatal in the truest sense of the word.
Researchers have found another fascinating winter adaptation of the deer using stomach tubes that they inserted into anaesthetised deer for short periods of time: In winter, the deer heart beats only slightly and the pulse is up to 60% lower than in the summer. The deer can even adapt their organs during the inhospitable period. The digestive tract (rumen) is reduced in size and the small rumen villi shrink. This saves energy during metabolism.
In winter, the red deer needs rest and plenty of time to eat its “low-calorie” food. Frequent disturbance of its habitat causes stress, frequent escapes lead to energy loss. This worsens the physical condition, which can lead to death by exhaustion during the harsh winter conditions.
With consideration and mindful behaviour in the wilderness, we humans can still enjoy the white snow-covered winter landscape. Be it off-piste skiing, snowshoeing or winter hiking:
- Respect wildlife sanctuaries and other protected areas: They provide retreats for wild animals.
- Stay on paths and designated routes in the forest: This helps wild animals to get used to people.
- Avoid forest edges and snow-free areas: These are the favourite places of wild animals.
- Keep dogs on a leash, especially in the forest: wild animals flee from free-roaming dogs.
- Dusk and night belong to the wild animals
Red deer research in the canton of St. Gallen