Telecoms infrastructure takes huge toll on birds

Millions of migrating birds are dying every year in collisions with communications towers and buildings.

Experts discussed the possible extent of this annual mass killing - which has worsened in recent years with the erection of cellular telephone masts - at the first scientific session on the problem at the American Ornithologists Union meeting.

In one incident in 1998, 10,000 Lapland longspurs died in one foggy night. Deprived of visual navigation features, the birds apparently mistook lights on a 130m mast in Kansas for the moon and homed in, smashing into the tower and guy ropes.

Such massacres are not isolated. Some estimates suggest as many as 100 million birds are killed every year in such collisions. "The more towers, the more dead birds," said Bill Evans, consultant ornithologist at the Cornell Laboratory of Ornithology in the United States. "Many of these species face degraded habitats at both ends of their migration flights, and the thousands of towers are a new threat along the way." The possible erection of 300 million digital television towers in the US over the next decade threatens to make the situation far worse.

Some experts at the meeting, which included biologists, environmentalists and representatives of the telecommunications industry, suggested that more research was needed on the effect of mast-top lights on bird behaviour.

Michael Mesure, of the Fatal Light Awareness Programme in Canada, said lighting cuts in tall buildings were saving thousands of birds in Toronto, where strobes have replaced spotlights at six power stations.

It is also possible that radio signals may interfere with birds' ability to "read" the earth's magnetic field.