The situation of breeding birds

2022 was the warmest and in some areas the sunniest year in Switzerland since records began in 1864. It was also a very dry year, especially in spring and summer. A year earlier, in 2021, spring was cold and wet, followed by a rainy and at times cool summer, with an unusual number of hailstorms in June and July. Many species had lower breeding numbers in 2022 than in 2021 or failed to continue the rising trends of previous years.

The documented breeding population of Pallid Swifts rose from 25 pairs the previous year to 65 pairs in 2022, thanks to newly discovered colonies in Brig and Geneva.
Photo © Daniele Occhiato

Photo © Swiss Ornithological Institute

In many reed breeders, such as the Common Reed-warbler (photo), breeding numbers were lower in 2022 than in 2021. Massive rainfall and local hailstorms towards the end of the 2021 breeding season are likely causes.
Photo © Mathias Schäf

Since the start of the «Monitoring common breeding birds (MHB)» surveys in 1999, breeding numbers of Whinchat and Eurasian Skylark have decreased steadily across Switzerland. While we have seen rising trends in MHB plots above 1500 m asl in the last 10 years, numbers at lower elevation are declining. Almost no Whinchats were found below 800 m asl, making it impossible to estimate a trend for this elevation zone.
Photo © Swiss Ornithological Institute

Trends differ from last year

Trends took a downturn in 2022 for a remarkable number of birds of open landscapes. For instance, the populations of almost all finches and buntings were smaller in 2022 than the year before. The Corn Bunting was a notable exception. In 2022, Corn Buntings bred in various sites that had been abandoned for several years. The differing trend of Corn Bunting compared to other birds of open landscapes suggests that many Corn Buntings seen here in 2022 came from abroad. This could be linked to the extreme aridity, which was even more pronounced in wide parts of the species’ Mediterranean range than it was in Switzerland. In another noteworthy finding, counts of reed birds were consistently lower in 2022 than in 2021. Many of them were probably still breeding when Switzerland was afflicted by excessive rain and hail in June and July of 2021. Low water levels in spring and summer 2022 may also have contributed to the low counts. Studies indicate that territory numbers of reed breeders and other wetland birds are lower in years with low water levels.

Encouraging trends

For the past several years, we have seen upward trends in some areas for Little Ringed Plover and Common Sandpiper. Both species benefit from extensive river restoration projects. However, the desired effect only unfolds when visitor management concepts are put in place to avoid disturbance.

Two further species have benefited from support efforts in breeding grounds: both Eurasian Scops-owl and Eurasian Wryneck have significantly increased, with 2022 seeing the highest numbers in many years. Mistle Thrush, Eurasian Blackcap and Eurasian Magpie are common species with consistent positive trends. As these species begin breeding early in the year, they were presumably less affected by the difficult conditions in summer 2021. While Magpie numbers continue to grow, the trend of Carrion Crow has plateaued in the last 15 years, indicating that a saturation level has been reached.

Negative trends continue

Several species have ongoing downward trends, with 2022 marking the lowest counts since 1990. The declines of Great Crested Grebe on waterbodies with important populations like Lake Neuchâtel and Lake Sempach are of particular consequence. Losses of European Turtle-dove also continue unabated. The species has disappeared from many former breeding areas. Citril Finches are in decline as well. The literature cites several possible reasons, including the impact of climate change in breeding and wintering grounds. Finally, White Wagtail numbers have reached the lowest level since the start of the MHB monitoring scheme.