2023-05-15 19:07:55
Today there are a quarter fewer birds buzzing over the fields, through forests and in the cities of Europe than four decades ago. According to a research team with Austrian participation, intensive agriculture is the main reason for the loss of birds. Plant protection products and fertilizers that are spread over large areas cause their food, such as insects and worms, to disappear. Climate change is also affecting species that are used to the cold in Austria. The study was published in the specialist journal “PNAS”.
A team led by Vincent Devictor from the University of Montpellier (France) examined the “population development” of 170 bird species observed at over 20,000 locations in 28 European countries, including Austria, over a period of 37 years (1980 to 2016). Overall, it was therefore on average across Europe by a quarter (25 percent) less, according to the researchers. The decline is worst among residents of farmland and grazing land, amounting to 57 percent. City birds were decimated by 28 percent and forest birds by 18 percent. There are 40 percent fewer birds living in cold areas and 17 percent fewer animals living in warm areas.
“We are also quite trendy in Austria,” said Benjamin Seaman from BirdLife Austria in an interview with APA. “The field and meadow birds are doing particularly badly in this country, and that coincides with the results that came out in this study across Europe.” Even the number of forest dwellers is falling, although the forest areas in Austria are increasing.
The researcher explains this by the fact that many of them not only live in the forests, but also visit neighboring meadows, pastures and fields. “Of course we also have a lot of forest areas that are doing badly, such as all the spruce monocultures in the lowlands,” said Seaman: “That can also be a reason why the forest bird species are doing badly.” The populations of birds used to the cold are also dwindling in this country. Only the number of thermophilic species is relatively constant, as the study found.
The researchers’ analyzes showed that of all human-caused factors, agricultural intensification is affecting bird populations the most. The hardest hit are those species that feed on “invertebrates” such as insects and worms. To a lesser extent, increasing urbanization is also declining bird populations. The same is true for temperature changes caused by climate change, although there are species that benefit as well.
This is “a very meaningful study,” said researcher Jan Christian Habel from the Zoological Evolutionary Biology working group at the University of Salzburg, who was not involved in the study, to the German Science Media Center (SMC). The colleagues’ investigation also reveals “the sharp decline in invertebrates, such as insects, and the overall condition of the landscape”.
The new work makes it possible to show what the main drivers of these developments are over the long period of investigation and how many losers are compared to relatively few winners. This shows that “the intensification of agriculture with the use of pesticides and nitrogen inputs reduces the quality of the habitat, which has a direct and indirect impact on bird diversity – due to the strong and widespread decline in insects as a food resource”. Habel hopes that the study will “wake up the reader, and hopefully the politicians too.”
(S E R V I C E – https://doi.org/10.1073/pnas.2216573120)
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