Shazam for birds

Whip-poor wills, boobooks, and moreporks repeat their name all night long.Chachalacas, chickadees, and chiffchaffs do the same during the day.So do cuckoos, kittiwakes, motmots, koels, phoebes, hoopoes, dickcissels, and many more.It is not surprising that onomatopoetic bird names are common across human languages.Many birds are heard more easily than they are seen, and most birds have unique, species-specific vocalizations ( Fig. 1 ).In this issue of PNAS, Sethi et al. ( 1 ) show how this basic fact of bird biology can be combined with modern technology to glean insights into bird species and communities.Scientists use the species-specific information content of birdsongs to conduct research across a range of disciplines.Evolutionary biologists study geographic variation in song to help define which populations constitute different species ( 2 , 3 ), conservation biologists broadcast song to attract individuals to new breeding areas ( 4 , 5 ), and ecologists monitor terrestrial bird populations by documenting what bird species they detect at specific locations, mainly by identifying singing individuals.For example, the North American Breeding Bird Survey does exactly what its name suggests by asking qualified volunteers to drive along backroads at dawn in the early summer, stopping every mile to listen for three minutes ( 6 ).By repeating these surveys over 50+ y,