Babbler birds are actually communicating much like humans when they make their distinctive sounds, new research reveals.
The calls are not merely sounds but convey specific meanings, investigators found. These animals piece together a series of specific sounds to communicate ideas.
Investigators believe this is the first time animals other than human beings are known to use combinations of sounds to express a specific meaning.
"It is the first evidence outside of a human that an animal can use the same meaningless sounds in different arrangements to generate new meaning. It's a very basic form of word generation — I'd be amazed if other animals can't do this, too," said Andy Russell of the University of Exeter.
The chestnut-brown babbler is a highly-social bird that makes its home in the Australian outback. These animals do not sing but are able to piece together otherwise meaningless sounds to communicate ideas.
"Although previous studies indicate that animals, particularly birds, are capable of stringing different sounds together as part of a complex song, these songs generally lack a specific meaning and changing the arrangement of sounds within a song does not seem to alter its overall message," said Sabrina Engesser of the University of Zurich.
Just as parts of music, such as verses and choruses, can be referred to as "A" or "B" parts, researchers studying the birds labeled similar parts of calls by various letters. For instance, as babblers fly, they produce an "AB" sound. When they feed chicks, the birds call out in a "BAB" pattern. When researchers played back the BAB sound to the birds, the animals looked to the nests. Playing the AB call caused the babblers to look to the sky for birds in flight. Investigators discovered that it was the arrangement of the elements, rather than the sounds themselves, that carried the meaning.
Researchers believe that different arrangements of the elements of calls can radically alter the meaning being conveyed by the animal. This is akin to the difference in English between "Dog bites man" and "Man bites dog."
"This is the first time that the capacity to generate new meaning from rearranging meaningless elements has been shown to exist outside of humans," Simon Townsend from the University of Zurich stated in a university press release.
Study of how the birds use strings of sounds to communicate could help biologists and paleontologists learn more about how our distant ancestors may have first developed linguistic skills.
Analysis of the calls of chestnut-brown babblers and what it can tell us about the development of human language was published in the journal PLOS Biology.
Photo: Gisela Gerson Lohman-Braun | Flickr