April 26, 2006

Starlings recognize grammar pattern in songs

LONDON (Reuters) - European starlings are not just
exceptional songbirds and mimics they also recognize a grammar
in their songs in a way that was thought to be unique to

Scientists in the United States have discovered that the
birds can be taught to identify different patterns of
organizing sounds used to communicate.

"We show that European starlings accurately recognize
acoustic patterns defined by a recursive, self-embedding,
context-free grammar," said Timothy Gentner of the University
of California San Diego (UCSD), in the journal Nature.

Recursive grammar, in which words and clauses are inserted
into sentences to create new meaning, is found in all human
languages. It was considered a type of linguistic boundary that
separated humans from other creatures.

"Now we find that we have been joined on this side of the
boundary by the starling. It should no longer be considered an
insult to be called a bird-brain," said Daniel Margoliash of
the University of Chicago, a co-author of the study.

While humans change a sentence from "the bird sang" to "the
bird the cat chased sang" by inserting words, starlings combine
chirps, warbles, trills, whistles and rattling sounds.

The scientists discovered their ability by recording eight
different starling sounds and combining them to make 16
artificial songs, some more complex than others, which had
different grammars or patterning rules.

After teaching the birds to recognize the different sets of
songs, nine out of 11 birds could distinguish the patterns and
grammatical rules.

"These birds are a lot smarter than you might think," said
Margoliash. "They have innate abilities. They solve interesting
problems and learn difficult tasks."