Climate, the resilience of birds depends on how they migrate

The way in which migratory birds redistribute themselves in the quarters where they reproduce and winter affects their resilience to climatic and environmental changes, according to an international study led by researchers at Milans Statale University and published in Ecology Letters.

The work is the first publication stemming from data present in the European Migration Atlas, a project which ended in 2022 and which was funded by the Italian government and the Convention for the Conservation of Migratory Species, which was produced with the help of the Statale in collaboration with environment agency ISPRA and other international partners.

Thanks to this study, the researchers discovered that a good indicator for the conservation of species is migratory connectivity, a measure that reflects the degree through which migratory birds tend to stay together both in their winter quarters and in those of reproduction, explained Roberto Ambrosini, coordinator of the study.

Thanks to an enormous dataset of sightings of birds fitted with recognition rings, for over a century, we have identified the eco-evolutionary factors underlying the migratory connectivity of the birds that migrate between Europe and Africa.

Examining almost 150,000 individuals of 83 species of short- and long-range migratory birds, the researchers went on, we have shown how migratory connectivity essentially depends on geographical variables like the distance of migration and the extension of the area in which the populations migrate, which, in turn, depends in the final analysis on the shape of continents".