Due to climate change, the habitats of some migratory birds along their East Atlantic turmoil are threatened. This emerges from a current report. In northwestern Europe, the rising sea level is already one of the main loads, the common Wadden Sea secretariat in Wilhelmshaven announced on the occasion of the publication. The Wadden Sea off the coasts of Denmark, Germany and the Netherlands is considered the hub of the East Atlantic bird train. In the wetland awarded by the UNESCO, millions of birds eat food reserves for their onward flight between Africa and the Arctic.
Climate change has an impact on most coastal areas, said Kristine Meise, head of the Zugweg and Biodiversity programme at the Wadden Sea Secretariat. In the Wadden Sea, for example, in addition to the rise in sea level, extreme weather events such as heavy rain and storms would increasingly affect the birds during rest and breeding. Also in the main wintering area off West Africa, the consequences of climate change are already being felt for migratory birds, for example due to erosion on the coasts, said Meise. According to the study, other factors such as overfishing, shipping traffic and logging have an even greater influence there.
The assessments of the habitat loads are part of the investigation report published at the end of April 2022. The project has been counted at the same time every three years of migratory bird populations along the East Atlantic bird train. More than 13,000 people in 36 countries were involved in the counting of 2020, the results of which are now available.
It is necessary to capture migratory birds at the same time
Such regular counts are important in order to recognize changes in the populations at an early stage, said Meise. »The difficulty is that a migratory bird usually does not stay in one place, and sometimes it changes his flight route. So it may be that the number of birds of a certain species in the Wadden Sea sinks, but the stock remains stable or even increases globally. «In order to measure the global stock, all places where the birds can occur should therefore be recorded at the same time become.
The previous census had shown that in 2020, compared to observation data dating back several decades, stocks increased in half of the total of 83 observed migratory bird populations. 16 Percent of the populations were stable, the researchers recorded a decrease in 30 percent – for example, in waders that breed in the Siberian Arctic.
According to Meise, a possible explanation for this is changing climatic conditions. "The migratory birds have adapted to certain times for thousands of years." Because of the climate change, spring and thus the melting of snow and slipping of insects in the Arctic begins. This would result in worse conditions for the brood and rearing of young birds, Meise said. This could explain a decline in breeding success.
In order to counter threats and preserve migratory birds, the authors of the report cite the protection of preferred bird sites and the sustainable management of habitats as central measures. (asw)
