Great tits sing with syntax

Rachel Feltman in the Washington Post:

Until now, only humans seemed to use syntax this way. But a study published Tuesday in Nature Communications suggests that the Japanese great tit — a bird closely related to the North American chickadee — uses grammatical rules like these in its calls.

All language, human and otherwise, revolves around turning meaningless sounds into something more. It's widely accepted that many non-human animals use what's called referential communication — specific sounds mean specific things to the receiver. Beyond that, there are two kinds of syntax that make speech more complicated, but also more useful: phonological and compositional. Humans have both, and until this new study, non-human animals had only been shown to have the former.

Phonological syntax turns sounds that individually have no meaning into ones with meaning. Suffixes and prefixes are a good example in human language, and other animals use strings of different notes that are never used individually. The Campbell's monkey adds an “oooh” sound to the end of its vocalizations to increase the intensity of the message, and this sound is never used on its own — so that's another example. Another study found that some birds won't respond to calls unless the notes involved are made in the right order.

More here.