Gizmodo:
A new bird song is spreading like wildfire among Canadian white-throated sparrows, at a scale not seen before by scientists.
Birds rarely change their chirpy little tunes, and when they do, it’s typically limited to the local environment, where slight song variants basically become regional dialects. New research published today in Current Biology describes an extraordinary exception to this rule, in which a novel song sung by white-throated sparrows is spreading across Canada at an unprecedented rate. What’s more, the new song appears to be replacing the pre-existing melody, which dates as far back as the 1960s.
Birds sing to mark their territories and attract prospective mates. Traditionally, white-throated sparrows in western and central Canada sing a song distinguished by its three-note ending. The new song, which likely started off as a regional dialect at some point between 1960 and 2000, features a distinctive two-note ending, and it’s taking the sparrow community by storm. What makes the new ending so viral is a mystery to the study authors, led by Ken Otter from the University of Northern British Columbia.
“These songs are learned—otherwise new variants would not arise or spread,” Otter told Gizmodo. “Where it started could have been a single bird, but it then gets learned by others, and they would form tutors for other birds. It wouldn’t spread from a single bird.”
