How crows tell others to buzz off deciphered

AGGRESSIVE and destructive crows that have long been a bane of Japan’s suburbs are finally being warned off in their own language.

Dr Naoki Tsukahara, an expert in biosciences at Utsunomiya University has spent 20 years recording and deciphering the calls made by the birds and is using their own warning cries to convince them that they are in danger.

It is commonplace for hordes of crows to be seen fighting over rubbish on the street after they have torn through clear plastic bags of household waste awaiting collection.

The abundance of food has also encouraged more crows to roost in suburban parks, where they can become territorial and attack people, particularly in the spring breeding season. Dr Tsukahara’s company, Crowlab,

has created a sensor that can be placed close to a pile of rubbish to detect when a crow approaches.

It plays a recording of a cry that the birds use to warn each other that danger – a cat, a hawk or even a human – is lurking nearby. Dr Tsukahara estimates that he recorded 10,000 crow calls before he was able to isolate those that were warnings.

The device, called the Crowcontroller was tested in a district of Utsunomiya City, north of Tokyo, between June and September of last year.

Footage on the company’s website shows crows looking for the source of danger and flying away without interfering with the rubbish when the recorded calls are played.

Testimonials on the Crowlab web site are glowing, with one resident of Utsunomiya saying it is good to see the birds flying away as it “makes me feel safe”.