Bird-speak and human-speak aren’t so different after all
A team of scientists have identified how birds vocalize and found that like humans, their method of communicating is seemingly reliant on vocal “building blocks.”
Prior to this study, scientists found that chestnut-crowned babbler calls were composed of two different sounds, labelled “A” and “B,” vocalized in different arrangements depending on behaviors. For example, when flying, the babbler vocalized a flight call, “AB,” but when feeding chicks, they produced “BAB” calls.
In the new study, the research team used playback experiments, used to test speech-sound discrimination in human infants, to examine the perception of babblers’ calls.
“Through systematic comparisons we tested which of the elements babblers perceived as equivalent or different sounds,” said lead author Sabrina Engesser, from the University of Zurich. “In doing so, we were able to confirm that the calls could be broken up into two perceptually distinct sounds that are shared across the calls in different arrangements. Furthermore, none of the comprising elements carried the meaning of the calls, confirming the elements are meaningless.”
“This system is reminiscent of the way humans use sounds to form meaningful words,” added co-author Andy Russell, from the University of Exeter.
“This is the first time that the meaning-generating building blocks of a non-human communication system have been experimentally identified,” said last author Simon Townsend, from the University of Zurich and the University of Warwick. “Although the building blocks in the babbler system may be of a very simple kind, it might still help us understand how combinatoriality initially evolved in humans.”
This discovery could help other researchers generate meaning from other animals’ vocalized building blocks, however, the researchers note that there are big differences between animals’ systems and word generation in language.
These findings are published in the journal Proceedings of the National Academy of Sciences.
Image Credit: Niall Stopford