Conservationists hope bees will repel the crows, based on the insects' tendency to attack anything dark-coloured 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.
The terns 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 Little Tern Project. "One thing we tried was putting netting in the trees and stringing up fishing lines, but nothing worked."
Observations suggest that using bees to battle crows will turn out to be an effective solution. It is believed that the bees' reaction is linked to the colour of bears' fur. The insects apparently attack dark-coloured creatures to protect their hives from plunder.Around 20,000 honeybees currently patrol the terns' nests "It is not 100 percent foolproof yet, because the area is quite large, and there do seem to have been fewer birds here this year so far," said. Masuda "But we are hopeful that it will prove effective over the long term.”