The Wadden Sea off the coast of Denmark, Germany and the Netherlands is considered the center of bird migration in the East Atlantic. Millions of birds accumulate reserves for their onward flight between Africa and the Arctic in wetlands inscribed on the UNESCO list.
Extreme weather affects the birds in the Wadden Sea
Climate change is affecting most coastal areas, says Kristine Meise, Program Manager for Migration and Biodiversity at the Wadden Sea Secretariat, on the occasion of the publication of the investigation report. In the Wadden Sea, for example, in addition to sea level rise, extreme weather events such as heavy rains and storms increasingly affect birds during rest and breeding.
Africa: overfishing, shipping, deforestation
Meise says the effects of climate change, such as coastal erosion, are already being felt by migratory birds in West Africa’s main wintering area. However, according to the study, other factors such as overfishing, shipping and logging are more influential there. Habitat pollution assessments are part of a research report published in late April. The project has counted migratory bird populations along the East Atlantic bird migration every three years since 2014.
The result of the international bird census is available
More than 13,000 people in 36 countries participated in the most recent census in 2020, the results of which are now available. Such regular counts are important to identify changes in populations at an early stage, says Meise of the Wadden Sea Secretariat. “The difficulty is that a migratory bird usually doesn’t stay in one place – and sometimes it changes its route as well. It is possible that some species in the Wadden Sea are declining, but globally the population remains stable or even increasing. “
Some populations are declining while others are growing or steadily
Therefore, to measure global population, all locations where birds may be present would need to be recorded simultaneously. The last census took place in 2020. Compared to the observational data from several decades ago, it showed that half of the 83 observed migratory bird populations increased. 16 percent the population was stable, while researchers saw a decline of 30%. – e.g. in the case of waders that breed in the Siberian Arctic.
The cycle of nature shifts and triggers a chain of problems
A possible explanation for the shrinking population is changing climatic conditions, says Meise. “Migratory birds have adapted to certain times over thousands of years.” Due to climate change, spring begins earlier, and with it, snow melts and insects breed in the Arctic. Meise explained that this would result in poorer breeding and rearing conditions for young birds. This may explain the decline in breeding success. In order to counter threats and conserve migratory birds, the authors of the report cite the protection of preferred bird habitats and the sustainable management of habitats as key actions.