In late winter, White-throated Sparrows erupt into song, easily set to human words: “Old Sam Peabody, Peabody, Peabody.” Or “Oh, sweet Canada, Canada, Canada.” But something changed since those classic memory aids were coined. Sixty years later, the bird sings a simpler, shorter song. Bird song, like human language, changes. By the 1960s, the bird’s longer song became rare. Researchers suggested that the “classic” song had — for some unknown reason — died out, to be replaced by a shorter version.More info and transcript at BirdNote.org. Want more BirdNote? Subscribe to our weekly newsletter. Sign up for BirdNote+ to get ad-free listening and other perks. BirdNote is a nonprofit. Your tax-deductible gift makes these shows possible.