This Bird Song Went Viral

In the 1990s researchers in western Canada noticed a local variant of the song of white-throated sparrows — ending with two notes rather than three. There are well-documented cases of bird species changing their song over time. But new dialects tend to stay local instead of replacing the traditional song more widely. In this case, though, a study found that the once-rare two-note song went "viral" among birds across more than 1,800 miles of Canada between 2000 and 2019. Now it has completely replaced the historic song in the region. Nobody knows why sparrows found the two-note ending so catchy.

"As far as we know, it's unprecedented," says Ken Otter, senior author of the research. "We don't know of any other study that has ever seen this sort of spread through cultural evolution of a song type." More at: https://biodiv.us/2Dor21u