Birds are worse off on Swiss farms than on agricultural land in neighbouring countries, according to a scientific study.
Bird populations are 25% lower on Swiss farms compared to bordering regions of France and Germany. There are 12% fewer species in Switzerland, the study found.
Field birds, such as the yellowhammer are affected just as much as generalists, such as sparrows or forest birds.
Aerial photographs point to the causes of the disparity in bird numbers on farms in different countries.
French farms have more hedgerows than in Switzerland while German farms have a greater range of structures that can be used to roost.
However, the authors note that the gap between Switzerland and neighbouring countries is reducing as Swiss farming methods improve.
The study was carried out by federal technology institute ETH Zurich and the Swiss Ornithological Association and published in the journal Ecological Economics.