A study of Peregrine Falcons in Eurasia is shedding new light on bird migration.
Millions of migratory birds have seasonally favorable breeding grounds in the Arctic, and they spend their winters in different locations across Eurasia. However, little is known about the formation, maintenance, and future of their migration routes or the genetic determinants of migratory distance.
Xiangjiang Zhan, a professor at the Chinese Academy of Sciences, and colleagues combined satellite-tracking data from 56 Peregrines from Eurasian Arctic populations with genome data from 35 other Peregrines. They reported in the journal Nature that the migratory routes used by the 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 were used across Eurasia, probably established between the last ice age 22,000 years ago and the middle-Holocene 6,000 years ago. Peregrines that migrated longer distances were also found to have a dominant genotype of the gene ADCY8 that — the authors suggest — may be associated with the development of long-term memory. It’s the strongest evidence yet of a “migration gene” in birds, they say.
The researchers also looked at simulations of likely future migration behavior to predict the impact of global warming. If the climate warms at the same rate it has in recent decades, they predict Peregrine populations in western Eurasia have the highest probability of population decline and may stop migrating altogether.
“In this study, we were able to combine animal movement and genomic data to identify that climate change has a major role in the formation and maintenance of migration patterns of Peregrines,” 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.