Migratory (迁徙的) birds are declining globally because of the way that humans have changed the landscape over recent decades — according to new research from the University of East Anglia (UEA).
A new study published today reveals that population declines have been greatest among species that migrate to areas with more human infrastructure — roads, buildings, power lines, wind turbines (涡轮机) — as well as more population and hunting levels.
Dr. James Gilroy, from UEA's School of Environmental Sciences, said, "We know that migratory birds are in greater decline than non-migratory species, but it's not clear why. We want to find out where in their life cycles these migratory species are most exposed to human impacts."
The research team identified 16 human-induced threats to migratory birds, including infrastructure associated with bird disturbance and impacts, transformation of land from natural habitat to human land use, and climate change. Advances in satellite imagery allowed the team to map each of the 16 threats across Europe, Africa and Western Asia. The team also created the first ever large-scale map of hunting pressure across the region. A total of 103 species of migrating birds were studied, including many rapidly declining species like the turtle dove and the common cuckoo, using large-scale datasets. The team calculated threat scores for factors such as habitat loss and climate change, across breeding locations, as well as non-breeding ranges. They then explored the relationships between these threat scores and bird population trends calculated from 1985 to 2018 by the Pan-European Common Bird Monitoring Scheme (PECBMS).
Dr. Aldina Franco, also from UEA's School of Environmental Sciences, said, "Our findings are important because we need to understand where declining species are being most impacted by humans across their seasonal migrations. Locating where birds are most exposed to these threats could help us target conservation actions."
