Green winter is wreaking havoc on mountainous areas and their inhabitants. All residents? no Mild temperatures are a boon for our herbivorous wildlife. “They need less energy and have more food,” says Kurt Bollmann, 60, a wildlife ecologist at the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL).
Because winter, which is a white fairy tale for us, is a fierce struggle for survival by most wild animals to keep their body temperature high. Even typical mountain animals such as mountain goats and chamois, which deplete their fat reserves before winter, experience the highest mortality towards the end of winter. That’s why they benefit: “It’s as if the living rooms are better heated and the pantry is more accessible.” The mild weather is a godsend, especially for the deer. They have less body reserves and, with their slender legs and narrow hooves, are less able to move around in deep snow – they now eat more easily and more easily in the mountains.”
Cockaigne for wild boar
Wild boars in the plains feel particularly comfortable in hot weather: they forage for food in the currently soft upper layer of the soil. According to Bollmann, it is not yet possible to say at this point whether the hunting requirements will be increased for 2023. “But for more wild animals surviving the winter, preconditions are good with a moderate start.”
No matter how many animals currently enjoy mild weather, winters like this will become a problem in the long run. “If this becomes normal, it will affect interactions in the ecosystem,” says Bollmann. The accumulation of strong temperature fluctuations typical of climate change is deceptive: “It makes the soil sometimes muddy, sometimes hard as frozen rock.” 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 ferrets.
Danger for hibernators
For hibernators, the rise in temperature only becomes problematic if it lasts long. “A woodchuck enters its den in October, whether it’s 5 or 20 degrees,” says Bollmann. Because the onset of hibernation is hormonally controlled by the rhythm of day and night. Because there is snow at high altitudes despite the mild temperatures, the marble nest is insulated from above like an igloo. The climate inside remains almost unchanged despite the mild outside temperatures.
For those who hibernate like hedgehogs or bats, this season may be more difficult. The danger isn’t that great this early in the winter, but they may wake up in February when it gets that hot again. “It puts a lot of energy into them,” says Thomas Wirth, a biodiversity expert at WWF. “Many changes between the warm and cold stages deplete their reserves. If they then wake up too early and can’t find food because the insects are still missing, they are in danger of starving.”
Birds stay here more often
Wintering birds also benefit from the absence of frost and snow. “Some even save themselves from the grueling journey south,” says Livio Rey, 32, a biologist at the Sempach ornithological station. That’s because it’s the availability of food, not the temperatures, that compels the birds to fly south. For example, it has been observed for some time that red kites and white storks spend the winter in Switzerland. “If there’s no snow, they’ll find enough food here in the winter and tend to stay here,” Rey says.
Experts agree that a bigger problem than the current mild temperatures is the climate crisis. “The interdependent species schedule is mixed, the plants are less pollinated, the insectivores find little food for their young,” says WWF’s Wirth.