Watch Out, Come Here: the Birds That Build Sentences
A Japanese Tit has different words for different dangers. A harsh, rattling jar-jar-jar means a snake. A thin, high hi-hi-hi means a hawk. And by putting two calls together — one that means “watch out” and one that means “come here” — the bird produces a phrase whose meaning is the combination of both: watch out and gather.
That is the claim of Toshitaka Suzuki, an associate professor at the University of Tokyo's Research Center for Advanced Science and Technology, whose work on the Japanese Tit (Parus minor) has become one of the best-documented cases of compositional signalling in a wild animal. In 2022, at the International Society for Behavioral Ecology congress, he proposed “animal linguistics” as a field in its own right. His book about the work, I Can Understand Bird Words, has sold 240,000 copies in Japan, and his own city ward — Meguro, whose official bird is the tit — interviewed him about it this summer.
What the tits actually say
The Japanese Tit's vocabulary, as Suzuki's experiments decode it, includes:
- Jar-jar-jar — snake. The birds typically mob a snake from above, and other tits, and other species, respond.
- Hi-hi-hi — hawk. Delivered from cover; the response is to drop silent and still.
- Pii-tsupi — a general “watch out, scan” note.
- Jiji-jiji — “come here”, used to rally other birds.
- Pii-tsupi jiji-jiji — the two combined, and this is the interesting part: the tits respond as if they have been told to both stay alert and assemble.
- Bibi-bibi-bibi — a chick's “feed me”. Tsupi-tsupi — a territory announcement from a male.
The calls pair with a private life that is also fairly talkative. When a female gives a hunger call, her mate answers that he is nearby — and then arrives with food. In other words, the tit's world is not a random noise of alarm; it has distinct signals, and those signals can be combined into longer messages.
The multilingual bit
Even more useful for a listener: the tits seem to understand the calls of other species. Suzuki's observations suggest Willow Tits, Varied Tits and Japanese Tits all share the meaning of the “gather” call, and that Japanese Tits and Japanese White-eyes understand each other's calls as well. Different species, different voices, same message — the point of a mixed-species flock in winter, where several kinds of small bird travel together and each one's alarm benefits all of them.
That has an immediate consequence for anyone learning birds by ear. In a mixed flock you are not hearing one species repeat its own notes; you are hearing a conversation in which phrases cross between species. Learning the alarm calls first is often the fastest route to finding the bird that made them: a wave of agitation moves through a hedge faster than any of the birds in it can be seen.
The birds that changed their city
Suzuki's second observation is about culture. Japanese Tits have increased across Tokyo over the past fifty to sixty years, and the city's tits now nest in places no tit is born knowing about — including upturned flower pots on balconies. He argues that this is not instinct but a behaviour spreading through the tit world: a bird finds an artificial cavity works, others copy, and the practice becomes part of what a city tit knows.
“Birds are creating culture in their lives and changing the world with their own hands,” he says. “In that respect they are just like us.”
The larger argument is philosophical. Suzuki proposes that treating language as a uniquely human property blinds us to what is actually happening outside the window: “We have become frogs in a well,” he told the ward magazine. He hopes that when children learn a phrase of tit — and his book's children's edition comes with a QR code of real recordings — they gain something more useful than a fact: the habit of listening.
Learning two words of tit
You do not need a study site. Stand near any hedge or park edge in Japan, Korea or north-eastern China — or, with its close relative, anywhere in Europe — and the tit chorus is the most legible thing in it.
Two voices, then: the tit's own two-note phrase, and the raptor it is announcing. Once you can tell those apart, you have started hearing structure rather than noise — which is the whole point of Suzuki's field of animal linguistics.