Dig it: Songbirds have a concept of grammar. Timothy Gentner, a scientist at the University of California at San Diego, recently took some European songbirds and trained them to recognize a normal segment of birdsong versus one with a “clause” in the middle. As the BBC reports:

Of the 11 songbirds tested, nine were able to pick out the inserted phrases about 90 per cent of the time, the team reports in Thursday’s issue of the journal Nature.

Similar experiments on tamarin monkeys showed the primates could not recognize recursive grammar.

“An intriguing possibility is that the capacity to recognize recursion might be found only in species that can acquire new patterns of vocalization, for example, songbirds, humans and perhaps some cetaceans,” psychologist Gary Marcus of the University of New York wrote in a journal commentary accompanying the study.

This contradicts Noam Chomsky’s idea of “innate” grammar — which holds that grammar is something only humans possess, a mental capacity that emerges at a certain point in brain development, almost the way water crystallizes into ice at zero degrees. But as it turns out, songbirds have some wicked-cool abilities to distinguish variants of song, many of which also suggest an innate grammar. For example: Male zebra finches learn their songs from their fathers. When they’re exposed to taped songs from their own and other species, they wind up singing ones specific to their species. Something inside their brains is doing a bit of filtering. (For details, check page 348 of this great summary of songbird neurophysiology.)

(Thanks to Erik Weissengruber for this one!)