The North American White-throated Sparrow, whose song preferences are the subject of a new study.
WASHINGTON: Members of a species of Canadian sparrow famous for its lighthearted signature song are changing their tune, a curious example of a “viral phenomenon” in the animal kingdom, a study showed Thursday.
Bird enthusiasts first recorded the original song of the White-throated Sparrow, with its distinctive treble hook, in the 1950s.
Canadians even invented lyrics to accompany the song: “Oh my sweet, Ca-na-da, Ca-na-da, Ca-na-da.”
But beginning in the late 20th century, biologists began to notice that members of the species in western Canada were innovating.
Instead of a triplet, the new song ended in a doublet and a new syncopation pattern. The new ending sounded like “Ca-na, Ca-na, Ca-na”.
Over the course of the next two decades, this new cadence became a huge success, moving east and conquering Alberta, then Ontario. She started entering Quebec last year.
It is now the dominant version in over 2,000 miles (3,000 km) of territory, in an extremely rare example of the total replacement of the historical bird dialect by another.
Scientist Ken Otter of the University of Northern British Columbia and his colleague Scott Ramsay of Wilfrid Laurier University described the rapid pace of this transformation in the journal Current Biology.
“What we are seeing is as if someone is moving from Quebec to Paris, and everyone around them is saying ‘Wow, that’s a great accent’ and they are going to start adopting a Quebec accent,” Otter told AFP.
Their work was based on 1,785 recordings between 2000 and 2019, most of them made by them, but with contributions from citizen-scientists, who published the files on specialized sites such as xeno-canto.org.
In the western province of Alberta, about half of the recorded songs ended with the trio in 2004; ten years later, all the men had adopted the double.
In 2015, the western half of Canada had been converted to the double version, and by last year, the new song was well established in the western tip of the eastern province of Quebec.
At this rate, the historical triplet version may soon exist only on tape recordings.
– Bird influencers –
The males of the species sing to mark their territory, and all their songs share a common structure. In general, if a variation appears, it remains regional and does not advance in neighboring territories.
The study represents the first time that scientists have been able to show this type of spread on a large geographic scale, Otter said.
So how did it happen?
Probably in the same way that children return from summer camp humming new songs: Songbirds from different parts of Canada spend the winter in the same parts of the United States, and then return to their own homes in the spring.
The researchers verified this theory by marking some of the birds.
So it was that on the plains of Texas and Kansas, early adopters of the new western Canadian song (avian influencers, so to speak) popularized the trend among their eastern brethren.
Previous work has shown that young birds can hear a foreign song after listening to a recording.
But to really understand why men were willing to abandon the old song that had once served them well, scientists have to rely on theories.
Otter believes it may be because women were more attracted to the new song, so young men were quick to adopt it.
“There seems to be some advantage to adding new elements to your song that make it not necessarily more attractive, but it increases people’s attention,” Otter said.
Going back to the human example, it would be similar to “if all French women in Paris thought that a Quebec accent sounded much more interesting than a Parisian accent, and then they all started to adopt a Quebec accent.”
The hypothesis remains unverified.
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