for National Geographic News
Conservationists hope bees will repel the crows, based on the insects' tendency to attack anything dark-colored that approaches their hives.
This year beehives from rural areas were relocated to the top of a large water-treatment facility near Tokyo's international airport, where as many as 4,000 birds known as little terns nest after a long migration from Australia, New Zealand, and Papua New Guinea.
Although they are not endangered internationally, little terns are listed as "vulnerable" in Japan's Red Data Book of threatened species.
That's because the terns' nesting sites in the country are being destroyed by construction work and other human activities, so the birds are considered potentially at risk in the future.
The terns near the airport have long been victims of Tokyo's crows.
In a single prolonged attack five years ago, about 60 crows picked off roughly 300 eggs and 160 young birds, and fewer terns have come to the nesting site since then.
"The young can't defend themselves against the crows, so we tried to find ways to protect them at the nesting site," said Naoya Masuda, a member of the nonprofit Little Tern Project.
"One thing we tried was putting netting in the trees and stringing up fishing lines, but nothing worked."
Then a suggestion from a city water-bureau employee led the tern group to the Ginza Bee Project.
The Tokyo-based nonprofit, launched in March 2006, keeps hives in the upscale Ginza shopping district to educate urbanites about agriculture.
SOURCES AND RELATED WEB SITES