The sweet song of the White-throated Sparrow drifts through forests and meadows all summer long across Canada, the northeastern U.S., and the northern Midwest. Field guides tell us that the song they sing sounds like Oh-sweet-canada-canada-canada or Old-Sam-Peabody-Peabody-Peabody.
But, Dr. Ken Otter, from the University of Northern British Columbia, Canada, and colleagues recently discovered that some White-throated Sparrows are changing their tune. Now the sparrows are singing Oh-sweet-cana-cana-cana, a new dialect, dropping that extra syllable.
Dr. Scott Ramsay, from Wilfrid Laurier University in Waterloo, Canada, and co-author on the study first heard the shortened song in British Columbia and figured that the song was specific just to that population. But the team was curious if birds from other parts of Canada were singing the shortened, stuttered version of the song, so they set out to record White-throated Sparrows in different regions. To their surprise they found more and more individuals were singing the two-syllable ending in western Canada than before, but even more surprising is that when they recorded birds from eastern Canada, they were also singing the new tune.
To figure out when and where the new song started popping up, they turned to sound collections like the Macaulay Library. The sound collection in the Macaulay Library has recordings dating back to 1929 providing researchers with an excellent opportunity to track changes over time. They listened to hundreds of songs from across the U.S. and Canada including songs recorded by William Gunn dating back to 1951. From these recordings they began to see when and where the transition to the new song started happening.
The change in song, Otter and colleagues found, happened over a remarkably short time. In 2000 the two-syllable ending was found only in western Canada, but by 2019 birds as far east as Algonquin Provincial Park in Ontario were all singing the two-syllable ending. Now the three syllable song of the field guides is only heard in the far eastern populations of White-throated Sparrows.
How did the eastern birds learn this new song? Western sparrows and eastern sparrows overwinter in the same area where young birds learn the new song and bring it back to the breeding grounds.
Otter and colleagues found that song dialects can change over a period faster than previously thought. This change was observable thanks, in part, to community scientists who archived their recordings with the Macaulay Library. Otter’s team used 306 recordings from 150 Macaulay Library contributors. This study also demonstrates the value of sound collections. What other interesting discoveries are waiting to be uncovered in the Macaulay Library?
Thank you to all of the recordists who archived their recordings to help make this research possible.
Ed M. Brogie
G & B
Robert C Stein
Scott & Jill Tansowny