If you stay outside in a British garden until dusk for long enough, the blackbird’s song will sound like a conversation. Not rushed, melodic, and filled with small improvisations that sound almost planned. If no one has told you to listen for it, it’s more difficult to tell that the blackbird on your street sounds different from the one two towns over. Not in a big way. In a meaningful way.
This is something that scientists have said for a while now. Birdsong from dozens of species has been shown to have regional variations. British blackbirds are one of the best examples of this. Bird babies don’t know all of their songs when they first come into the world. They pay attention. They first copy their parents, then their neighbors, and then slowly make small changes of their own. When these changes happen over many generations, they create what ornithologists call a “geographic mosaic of accents,” which sounds like a loving term.
That phrase is helpful. Because it records more than just changes in pitch or speed. This phrase captures the idea that a bird’s song can tell you about its home range, much like a Geordie accent or a West Country drawl can. Birds that speak the same language usually know each other as locals. Females seem to use dialect as a rough way to tell if a potential mate fits in well with the area. That a bird sings the right version of the right song says something about its past, its fitness, and where it fits in.
What’s been going on in British cities has made this all more complicated. Blackbirds in cities now sing at a significantly higher pitch than blackbirds in the country. It’s easy to see why: low-frequency noise from cars, construction equipment, and other machines blocks out the lower registers of birdsong. If the birds move up, they can be heard over the noise. Studies have also shown that blackbirds in cities start their dawn chorus a lot earlier than blackbirds in the country, sometimes by several hours. This is probably because they want to get their songs heard before the morning commute drowns them out. Also, artificial light plays a part, pushing birds to start working out earlier in ways that are still not fully understood.
There’s an odd way that culture is being passed on here. As with people, a bird’s dialect isn’t just about its own unique habits. They are passed down, strengthened, and sometimes lost. One of the stranger examples is the yellowhammer. These birds were brought to New Zealand from Britain in the 1800s, but they still speak old British dialects that no longer exist in the UK, likely because population decline wiped out some of the original regional groups. A piece of Victorian bird song that has been kept alive on the other side of the world. One of those little things that makes you think for a second.
Because the blackbird is so good at imitating sounds, its dialect story is very interesting. These birds don’t just passively take in the songs around them; over time, they add new sounds on purpose. Blackbirds have been known to mix in human whistles, car alarms, and cell phone ringtones. Someone heard a bird consistently making noises that sounded like the second bar of “Colonel Bogey.” Someone else said they heard what sounded like a lively performance of “La Cucaracha.” It’s still not clear if these borrowed words will be passed down and become part of the local language. It’s possible, though, that what we call “urban blackbird song” is at least partly a record of the sounds around it—traffic, people talking, technology—that the bird listens to and changes into something it can use.
In contrast, blackbirds that live in rural areas tend to keep their slower, richer, lower-register songs that can be heard well in open fields and forests. In those places, there’s less of a rush. Not as much noise to deal with. It’s okay for the song to be bigger, softer, and more traditionally blackbird-like, whatever that means these days since so much has changed.
It’s still not clear where the lines between these regional forms are or how fast they change. But the research keeps showing the same thing: place affects song, and song affects identity. that the bird outside your window is singing in a small way about where it lives.
