The Language of Crows

This morning, at dawn, I listened to the morning news delivered by a large, black crow in the tree next to my bedroom window. This crow has a very large vocabulary, and its language is tonal, like Thai. Although crows can make only one sound, which in English we transcribe as "caw", in fact it uses the same five tones as Thai.

The morning news lasted about ten minutes, with frequent pauses, which I took to be the pause between sentences or paragraphs. This crow used repetition and tones to create different words. Unlike Thai, which only duplicates a word to indicate a generic plural, the crow would issue as many as five identical caws quickly, then pause slightly. I took the five caws to be one word or phrase.

Thai uses five tones: low, middle, high, rising, and falling. The crow used the same tones. There was clearly a "caw?" and a "caw!", which were quite distinct from the other three caws: low caw, middle caw, and high caw.

As far as I could tell, the crow did not repeat itself during the ten minute news announcement. I could not hear any answering crow, so I took this as general broadcast news, as opposed to "hey, I'm looking for a mate!".

In Thailand, 20 years ago, I lived at JB Mansion on Phaholyothin Road, Soi 3. I often went into the pool, but I had to wait until sunset, as I have fair skin and burn easily. There was a large bird, perhaps a parrot or toucan, in a cage that was obviously too small, on the balcony of the apartment building next door.

All day, this bird sent out a single whistle, which I took to mean, "Is anyone there?"

One day, I repeated the whistle back to him. It was easy to reproduce and I did it accurately.

The bird immediately perked up, shifted around on its perch, sat up straight, turned its head around in both directions, and issued a different whistle which I had never heard before.

I duplicated that whistle, and the bird looked confused. It tilted its head, shifted around, then issued the second whistle again.

I repeated it.

The bird settled down, and went back to issuing the first whistle.

So what happened here?

Clearly, if the first whistle meant "Is anyone there?", the second whistle meant "I am here, who are you?" and it should have been followed by a third whistle, which I did not know.

This is similar to the "discovery protocol" used in computer communications, for example with Bluetooth and Wi-Fi devices. An initial signal, called "Attention" in computer-speak, is followed by an "Acknowledgement", and then a "Begin Transmission". This is also termed a "handshake".

When communicating with the parrot, the handshake failed as I did not provide the correct third whistle, and the bird realized that I was not another parrot.

Getting back to the crow, it did not do what the parrot did, that is, issue a single sound repeatedly. It was clearly speaking different sentences for a long period of time, ten minutes, without repeating itself, as far as I could tell.

In Australia, some crows in the Northern Territory have figured out how to eat cane toads, which have two poisonous sacs behind the head. Normally, anything that eats a cane toad dies. Because of this, cane toads have spread southwards and have now reached Sydney. But the crows near Darwin have figured out that if they flip the toad onto its back, they can eat the cane toad by going through the stomach.

Amazing birds, crows. I never realized before today that they spoke a version of Thai. I wrote Speak Easy Thai to help people learn Thai; maybe I should write a Speak Easy Crow.