More than 6,000 of the world's 9,600 known bird species are suffering a serious decline in numbers, an environmental think-tank claims. Habitat destruction, pesticides, overhunting, industrial pollution and the introduction of alien animals are pushing species to the brink, a report by the Washington-based Worldwatch Institute said.
At least 1,000 species, including the Philippine eagle, the resplendent quetzal of Central America, the Galapagos flightless cormorant and the mallee fowl of Australia, face extinction.
Falling bird populations could also damage man's food resources. Numerous species, including birds of prey, play a key role in curbing insects and rodents. Others pollinate plants.
Howard Youth, the report's author, said yesterday: "The demise of once common birds indicates the deterioration of whole ecosystems including those on which human life depends."
Habitat loss, where wetlands and forests have been cleared to support human population increases, has accounted for the decline of at least half the 250 species that breed in North America and winter in Central America.
The number of whitethroat warblers, which breed in Britain, has fallen by three-quarters in recent years as their African wintering homes turn to desert.
Acidification of rivers and lakes is also killing the insects and fish on which some species survive.
Under the biodiversity treaty, signed at the Rio Earth Summit in 1992, nations pledged to curb losses of animal and plant species. Britain will publish its commitment today.
The report offers little hope that the decline will be reversed, particularly in the developing world.
