By KURATOSHI YOKOYAMA/ Staff Writer
February 28, 2020 at 08:00 JST
HACHINOHE, Aomori Prefecture--City authorities playing a game of cat and mouse with an unwanted population of noisy crows appear to be gaining the upper hand--for now.
Officials enlisted assistance for the project from CrowLab, a company based in Tochigi Prefecture and headed by Naoki Tsukahara, an animal behavorial specialist who has a deep knowledge about crows.
Residents have complained about bird droppings and the harsh, raucous calls the crows make.
Tests that started Feb. 4 and will continue until the end of March involve rigging up a loudspeaker near power lines in central Hachinohe where crows gather from early evening through late at night and inundating them with sounds to scare them away.
The birds began congregating in large numbers on the power lines more than five years ago.
Crow numbers tend to increase between October and March. In fiscal 2014, the city government received more than 60 complaints about squawking and bird dropping.
Officials also have shone flashlights at the birds to scare them off as well as setting off firecrackers.
Even though the birds took off for a while, they kept returning.
In a new experiment, a loudspeaker was set up near a flock of crows perched on power lines to emit special sounds that resembled the cries crows make when they are alarmed or sense danger.
During the first test on the evening of Feb. 4, a loudspeaker emitted sounds for 10 seconds directed at crows perched on the power lines. The flock flew upward and seemed flustered. The birds started flying in circles randomly as they were apparently panicked.
The same result was achieved in a test at a different location.
Tsukahara noted that crows are very smart and return quickly, even when people scare them away with flashlights. Because they have good night vision and recognize humans, they will return to the same spot if no one is around.
“I achieved the result I wanted,” Tsukahara said. "But we need to continue doing this.”
The team will test various crow calls so the birds do not get used to a particular call.
City authorities said the trials had exceeded expectations and that the tests will continue once or twice a week until the end of March.
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Naoki Tsukahara, right, uses a loudspeaker to scare crows perched on power cables in Hachinohe, Aomori Prefecture, on Feb 4. (Kuratoshi Yokoyama)
