Climate change could force birds to migrate hundreds of extra miles, according to new research. The extra distance might even be deadly.
Modelling by Stephen Willis, of Durham University, and his colleagues shows that the breeding ranges of Sylvia warblers will shift consistently north as the Earth warms. Non-breeding ranges showed no consistent directional shift, meaning longer migrations.
“From 2071 to 2100, nine out of the 17 species we looked at are projected to face longer migrations, particularly birds that cross the Sahara desert,” says Willis (press release). “Our findings show that marathon migrations for some birds are set to become even longer journeys. … The added distance is a considerable threat.”
According to the team’s paper in Journal of Biogeography, trans-Saharan migrants face an average extra flight of 413 km. The researchers write that the challenge facing many species is “unprecedented”.