The Bengalese finch is what happens when for 250 years, people breed the white-rumped munia for its snowy plumage. It’s paler than its wild counterpart, more social. And although its genetic architects (bird breeders) weren’t selecting for singing skills, the Bengalese finch has a far more complex, varied song. That last bit has some fascinating possible implications, concerning how we developed our own unique speaking abilities.
The capacity for complex communication requires a wide variety of skills. You don’t just need to be able to recognize and respond to certain cues; in order to parse the meanings of new or unfamiliar cues, you also need to be able to guess at the other party’s intent.
This is not something most wild animals have the bandwidth to do. For instance, wild foxes and wolves can’t recognize what it means when a person points to something. No amount of training will pass on the understanding. However, domesticated animals are the result of many generations of breeding that selected for sociability, among other traits. So maybe it’s no surprise that domesticated foxes, dogs, and even formerly domesticated dogs who have gone feral all have the capacity to learn pointing behaviors.
It’s possible that the same might be true for the Bengalese finch—and us. Unlike our feathered friends, our development into our present species wasn’t masterminded by some other creature, but it has been argued that the overall process was much the same. As selection pressures started to favor less aggressive, more sociable individuals, communication skills naturally increased.
It may, however, be a bit more complicated than that. Keep in mind, the Bengalese finch was not bred for its excellent social skills, but for the color of its feathers. In “Self domestication and the evolution of language,” James Thomas and Simon Kirby argue that the forces reshaping the finch’s song might be more cultural.
The Bengalese finch and the white-rumped munia both pick up their song from others of their species, learning best from an in-person (in-bird?) demonstration. In the wild, the white-rumped munia must be constantly on its guard, and transmitting its song accurately to its young could be a matter of survival. Fidelity is also key when it comes to identifying other white-rumped munia by call. But the tame Bengalese finch has adapted to a very different lifestyle, encountering plentiful food and few threats, and leaving the bird free to get a little creative with its vocalizations.
Could early humans have developed our own language thanks to the decreased stresses that came with living in larger groups? Did our first languages evolve from a sort of jazz freestyle of sounds from the first generations of proto-humans with a little time on their hands? We are a long, long way from knowing for sure.
In the meantime, the next time you point your dog towards a tennis ball, take a moment to thank our ancestors for their truly impressive wolf-breeding project. From White Fang to Rover, white-rumped munia to finch, domestication has made our lives easier and more pleasant—even if a little tamer.