Birds communicate through singing: but do they follow grammar?
In case you thought grammar is a unique gift from nature to man, it is time to pause and look at some latest research. According to Kentaro Abe of Kyoto University, Japan, Bengal finches have their own grammatical rules on which they base their rudimentary syntax. He says, ‘Songbirds have a spontaneous ability to process syntactic structures in their songs’.
To demonstrate the above, the research team carried out an experiment. After observing that in the wild, Bengal finches call back vigorously whenever they hear unfamiliar songs, usually from intruding finches, the research team took advantage of the trait to see how the birds would respond to ‘ungrammatical’ songs. The team played jumbled “ungrammatical” remixes of finch songs to the birds and measured the response calls.
The experiment
As a first step, the researchers played to finches unfamiliar songs time and again till the birds got used to them and stopped reacting with vigour. Then they jumbled up syllables within each song and replayed these versions to the birds.
“What we found was unexpected,” says Abe. The birds reacted to only one of the four jumbled versions, as if they noticed it violated some rule of grammar, whereas the other three remixes didn’t. Almost 90 per cent of the birds tested responded in this way. “This indicates the existence of a specific rule in the sequential orderings of syllables in their songs, shared within the social community,” Abe was led to conclude.
In a further experiment Abe showed that the rules had to be learned through social interaction and were not innate. Birds raised in isolation failed to react to the jumbled version until they had spent two weeks with other birds. Further, the team also taught birds unnatural grammatical rules by habituating them to one of the jumbled versions, then gauging their reactions to remixed versions that violated the “artificial” rules.
The conclusion
At the final stage, Abe chemically destroyed an area of the bird’s brain named anterior nidopallium in some birds, and was able to prove that it is vital for registering faulty grammar. In human beings, a region called Broca’s area gets activated when we hear ungrammatical sentences. Abe thus suggests that studying the counterpart region in finches might throw new light on the origins of human grammar.
Responding to the findings, Constance Scharff, who works on birdsong at the Free University of Berlin, Germany, says ‘It’s an ingenious experiment showing that birds are sensitive to changes in song that are consistent with different grammars…more and more, we are seeing similarities between humans and animals, and that makes some people uneasy’.