Deer don’t particularly like snow: With their slender legs, it’s harder for them to move around in deep snow.
Katja RichardEditor society
The green winter is taking its toll on mountain areas and their inhabitants. All residents? no The mild temperatures are a blessing for our herbivorous wildlife. “They need less energy and have more food,” says Kurt Bollmann (60), wildlife ecologist at the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL).
More reserves: Capricorns, used to the cold, also benefit from mild weather.
Because what is a white fairy tale winter for us is a tough struggle for survival for most wild animals in order to keep their body temperature high. Even typical mountain animals such as ibex and chamois, which eat up fat reserves before winter, experience the highest mortality rate towards the end of winter. That’s why they benefit: “It’s as if their living room is better heated and the pantry is more easily accessible.” The mild weather is a blessing, especially for deer. They have fewer body reserves, and with their slender legs and narrow hooves, they are less able to move in deep snow – now they find it easier and more to eat in the mountains.”
Cockaigne for wild boar
Wild boars in the lowlands feel particularly comfortable in warm weather: They dig for food in the upper layer of soil, which currently remains soft. According to Bollmann, it is not yet possible to say at this point whether the hunting requirements for 2023 will be increased. “But the prerequisites for more wild animals making it through the winter are good with the mild start.”
No matter how many animals are enjoying the mild temperatures right now, winters like this will become a problem in the long run. “If this becomes normal, it will affect the interactions in the ecosystem,” says Bollmann. The accumulation of strong temperature fluctuations, which is typical of climate change, is tricky: “This makes the soil sometimes muddy, sometimes frozen rock-hard.” This then becomes difficult for both wild boar and mice – the latter live underground in winter and are the most important food source for our weasels.
Danger for hibernators
For hibernators, the rise in temperature only becomes problematic if it lasts. “A marmot goes into its den in October, whether it’s 5 or 20 degrees,” says Bollmann. Because the start of hibernation is controlled hormonally and via the day-night rhythm. Because there is snow at high altitudes despite the mild temperatures, the marble burrow is insulated from above like an igloo. The interior climate hardly changes despite the mild outside temperatures.
Marmots descend for hibernation in October: the snow cover insulates and protects them.
It can be more difficult this season for hibernators such as hedgehogs or bats. The danger is not that great so early in winter, but when it gets that warm again in February, they could wake up. “It costs them a lot of energy,” says Thomas Wirth, a biodiversity expert at the WWF. “Many changes between warm and cold phases use up their reserves. If they then wake up too early and cannot find any food because the insects are still missing, they are in danger of starving to death.”
Birds stay here more often
The wintering birds also benefit from the lack of frost and snow. “Some even save themselves the arduous journey south,” says Livio Rey (32), a biologist at the Sempach ornithological station. Because it is not the temperatures that force the birds to fly south, but the availability of food. For example, red kites and white storks have been observed for some time to spend the winter in Switzerland. “If there’s no snow, they’ll find enough food here in the winter and they tend to stay here,” says Rey.
The rattle stork winters more and more often in Switzerland.
The experts agree that a bigger problem than the currently mild temperatures is the climate crisis. “The schedule of interdependent species gets mixed up, plants are less pollinated, insectivores find too little food for their young,” says Wirth from the WWF.