A study of peregrine falcons in Eurasia sheds new light on bird migration.
Millions of migratory birds have seasonally favorable breeding grounds in the Arctic and spend their winters in various locations across Eurasia. Little is known, however, about the formation, maintenance and future of their migration paths or the genetic determinants of migration distance.
Xiangjiang Zhan, professor at the Chinese Academy of Sciences, and colleagues combined satellite tracking data from 56 peregrine falcons from populations in the Eurasian Arctic with genome data from 35 other peregrine falcons. They reported in the journal Nature that the migration routes used by species have been shaped by environmental changes since the last Ice Age. The paper also presents evidence that the distance traveled during migration is influenced by a genetic factor.
The authors found that five migratory routes across Eurasia were used, likely between the last Ice Age 22,000 years ago and the Middle Holocene 6,000 years ago. It was also found that peregrine falcons that migrated over greater distances have a dominant genotype of the ADCY8 gene, which the authors suggest may be linked to long-term memory development. It is the strongest evidence to date of a “migratory gene” in birds, they say.
The researchers also looked at simulations of likely future migration behavior to predict the effects of global warming. If the climate has been warming at the same rate in recent decades, they predict that migrant populations in western Eurasia will have the highest likelihood of population decline and may stop migrating altogether.
“In this study, we were able to combine animal movements and genomic data to determine that climate change plays an important role in the formation and maintenance of migration patterns in peregrine falcons,” says Mike Bruford, a molecular ecologist from Cardiff University and one of the authors.
This article will be published in Birding Briefs in the May / June 2021 issue of BirdWatching.
Peregrine falcon observation and study at Rankin Inlet, Nunavut, Canada
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