But as in the human world, those who mix news with knowledge sometimes find success and their new song circulates through a certain society.
Usually it stops there, and Dr. Otter and his colleagues thought that this was only happening to their birds in western Canada, that “it was just an isolated, peripheral population” doing their own thing, he said.
However, when they tried to find out where the song’s interval ended, they realized that birds were singing the song in other areas as well. In 2004, half of the birds that the scientists recorded in Alberta sang duplicates instead of triplets. In 201
To get a better sense of the spread, the researchers turned to citizen science bird song databases. They drew with white throats from across Canada and the northern US and plotted them over time and by song type. On maps you can see the duplicate songs get prominent, their influence expands and is strengthened. By 2019, it had taken over completely from Yukon to Ottawa, a certified hit that currently borders the Northeastern United States.
By tracking the western Canadian birds with geolocators, they found that some of them spend their winters in the southern United States, where they overlap with birds from other places. They probably share the song there, like a mix that is passed around.
The possibility of birds changing songs in their wintering areas “really opens up how we think about song learning,” said Dana Mosely, an ecologist at James Madison University in Virginia who was not involved in the study. There is also evidence that birds “overwinter, where they stay in migration, and where breeders shape their behavior,” she said.
That a song should take off here is very unusual, says Dr Otter. It contradicts prevailing bird song theories, which emphasize the benefits of sticking to your own local song type. What happens to the sparrows is “like an Australian person coming to New York, and all the New York people suddenly decide to adopt an Australian accent,” he said.