Birds that produce faint chirps called flight calls during nighttime migration collide with illuminated buildings much more often than closely related species that don’t produce such calls, according to a new analysis of a 40-year record of thousands of building collisions in the Midwest.

The new analysis of more than 70,000 nighttime songbird collisions in Chicago and Cleveland suggests that birds disoriented by artificial light from illuminated buildings at night send out flight calls that may lure other nearby birds to their death.

The study was published online April 3 in Proceedings of the Royal Society B.

“Nocturnal flight calls likely evolved to facilitate collective decision-making among birds during navigation, but this same social behavior may now exacerbate vulnerability to a widespread anthropogenic disturbance: artificial light from buildings,” said University of Michigan evolutionary biologist Benjamin Winger, first author of the study.

A new Proc. Roy. Soc. B paper by Ben Winger, Brian Weeks and colleagues - Nocturnal flight-calling behaviour predicts vulnerability to artificial light in migratory birds

Learn more: