http://www.sciencemag.org/news/2019/04/tweeting-while-flying-kills-migratory-birds

Texting while driving can be deadly. So can tweeting while flying, a new study finds—among some species of migratory birds. Researchers have found that birds using faint, high-frequency vocalizations known as flight calls during their nighttime migrations are losing their bearings, crashing into buildings, and possibly luring more birds to their untimely ends.

Many bird species, including swallows, finches, and sparrows, use nocturnal flight calls to help the flock navigate while migrating. Past studies have found that these birds chirp more often when flying over urban areas with lots of artificial light, leading scientists to wonder whether the light disorients them and causes them to call out even more.