TOKYO — City Hall unleashed its most deadly measure to date Tuesday to control the big, ornery crows that attack people, zoo animals and garbage bags in Tokyo.
City workers began setting 100 fenced-in traps throughout Tokyo, hoping to lure the birds in and then gas them with carbon dioxide. The city intends to kill as many as 7,000 crows, or about a third of the population, by March.
The aggressive crows are as adept at picking off prairie dogs at the city zoo as they are at ripping open garbage bags and littering the Japanese capital's streets with rotten food.
"I've heard of these birds attacking kittens," task force leader Akira Ishii said as workmen hammered together the first trap in Yoyogi Park, where pine thickets reverberate with grating caws and the sky swirls with black silhouettes. "Something had to be done."
Rats are a worry in most big cities. And while there are rats in Tokyo, crows rank beside air pollution as the top metropolitan headaches for Gov. Shintaro Ishihara. The city is spending $236,000 on the crow traps.
The crow population in Tokyo has more than tripled — to about 21,000 — since 1985, despite repeated efforts to deprive them of garbage, their main food source. The increase is attributed to a number of factors, including the crows' ability to reproduce quickly and a lack of predators.
Besides plundering curbside trash like voracious dogs, Tokyo crows — which can have a wingspan of more than 3 feet — are known to dive-bomb people coming too close to their fortress-like nests during breeding season.
"Beware of Crows" signs hang in city parks.
"I hate them," said banker Miyo Sakai, victim of a fly-by attack. "It was a really scary moment."
Attacks at Tokyo's Ueno Zoo helped rally public support for the crow crackdown. For many people, the last straw was watching crows pluck up and devour baby prairie dogs or peck holes in the backs of hapless deer.
"It's a big problem for those poor animals," Ishii said.
The Tokyo government received 2,891 crow control complaints between May and August. Experts removed 464 nests, killed 1,064 chicks and destroyed 105 eggs.
The city also has moved garbage collection times closer to daybreak so trash isn't sitting out during crows' prime feeding hours.
Bird lovers applaud that move, but any talk of extermination ruffles their feathers.
"People misunderstand crows," said Meiko Kurosawa of the Wild Bird Society of Japan. "They are part of the wildlife in Tokyo, and we have to live in coexistence."
The species commonly found in Tokyo is the jungle crow. It has largely displaced the smaller carrion crow.