Birds are well protected against the cold
Concerned reports have been reaching the Swiss Ornithological Institute in Sempach: bird feeders are seeing little activity. But birds are well equipped to handle the cold. Here’s why.
In recent times, many reports from concerned citizens have been reaching the Swiss Ornithological Institute in Sempach LU, indicating that bird feeders are seeing little activity.
Is the unusually harsh winter weakening the birds, leaving them without the energy to forage for food?
This year, heavy snow is lying even in the lowlands. For the kingfisher, the common buzzard, the barn owl, and the kestrel, frozen waterways and a closed snow cover make finding food particularly difficult. How the current situation will affect bird populations remains to be seen in spring, says Livio Rey, spokesperson for the Swiss Ornithological Institute in Sempach.
However: “Just because small birds like finches and tits are not coming to the feeders does not mean they are struggling or have died”, says Rey. The Swiss Ornithological Institute assumes that many birds have so far still been able to find enough seeds, nuts, and berries from bushes and shrubs. Perhaps the birds will start visiting the feeders more frequently again following the heavy snowfall.
Birds fly to their food
Nevertheless, it is possible that some birds may not survive the harsh winter. “But populations can recover quickly after a single severe winter”, he says.
In fact, the birds that remain in Switzerland year-round have adapted over thousands of years to the harsh winter climate. And their ability to fly makes them more independent than other animals. When food is scarce, they simply fly to another location where conditions are better.
For example, a red kite can fly to Spain in just two days and fill its stomach there, says Rey. Accordingly, volunteers counted significantly fewer red kites in January than in other years — a sign that some birds fled the harsh winter.
Threatened migratory birds
In general, winters in this country are becoming milder. The world of migratory birds is responding accordingly: many birds from the north are wintering in Switzerland less frequently, as the waters in their breeding grounds no longer freeze over and they can therefore find sufficient food there. Conversely, some formerly migratory birds are increasingly staying in Switzerland and no longer travelling to southern Europe.
According to Rey, it is not harsh winters that pose a threat to the long-term survival of all birds, but rather habitats degraded by human activity, where breeding success is lower.
Mountain birds are coping well
Mountain birds such as the rock ptarmigan are also unaffected by the current weather conditions. They are accustomed to cold winters and find sufficient food in deep snow. However, as Rey explains, when they are disturbed by freeriders, ski tourers, or snowshoers venturing off marked routes, they expend valuable energy that they would otherwise need for raising their young or fleeing from predators.
They are also struggling with the increasingly warmer temperatures brought on by climate change. Unlike the chaffinch, for example, a rock ptarmigan cannot simply move elsewhere to breed. Mountain birds are therefore dependent on an intact alpine landscape. Rey also notes that Switzerland bears a shared responsibility to slow climate change in order to ensure the survival of these threatened mountain birds.
