Changing Their Tunes
The Singers: White-crowned sparrows in California’s Tioga Pass
The Songs: Mating songs recorded in 1979 (higher and faster) and 2003 (lower and slower)
The Back Story: Researchers played both the golden oldies and the recent hits for Tioga Pass sparrows. Like human teenagers, the sparrows showed a strong preference for the new songs over the old: Females exhibited mate-soliciting behaviors more often and males approached the speakers more aggressively when researchers played songs from 2003.
The Big Picture: Is this just a matter of taste, like a preference for Beyoncé over Donna Summer? Not quite. “These birds live about two years, so it’s close to 15 generations” since the 1979 recording, says Duke University researcher Elizabeth Derryberry. “It’s more like us listening to [the Middle English of] Chaucer.” An ecological explanation for the change: The newer, lower songs travel better through dense foliage, the result of decreased grazing on local public lands.