American songbirds are being wiped out by banned pesticides
By Leonard Doyle in Washington
Friday, 4 April 2008
The number of migratory songbirds returning to North America has gone
into sharp decline due to the unregulated use of highly toxic
pesticides and other chemicals across Latin America.
Ornithologists blame the demand for out-of-season fruit and vegetables
and other crops in North America and Europe for the destruction of
tens of millions of passerine birds. By some counts, half of the
songbirds that warbled across America's skies only 40 years ago have
gone, wiped out by pesticides or loss of habitat.
Forty-six years ago, the naturalist Rachel Carson wrote Silent Spring,
a study of the ravages caused to wildlife, especially birds, by DDT.
The chemical's use on American farms almost eradicated entire species,
including the peregrine falcon and bald eagle.
The pesticide was banned and bird numbers recovered, but new and
highly toxic pesticides banned by the US and European Union are being
widely used in Latin America.
Because of changed consumer habits in Europe and the US, export-led
agriculture has transformed the wintering grounds of birds into
intensive farming operations producing grapes, melons and bananas as
well as rice for export.
Ornithologists say another silent spring is dawning across the US as
birds are being poisoned by toxic chemicals or killed as pests in
their winter refuges across South and Central America as well as the
Caribbean. They say that many species of songbird will never recover,
and others may even become endangered or extinct if controls are not
put in place or consumer habits changed.
More problems await those birds which make it home. Millions of acres
of wilderness the birds use as nesting grounds have been ploughed
under in the drive to grow corn for ethanol, for bio-fuel.
Some 150 species of songbirds undertake extraordinary migrations up to
12,000 miles every year as they move from the south to nesting grounds
in the US and Canada every spring. Ornithologists say that almost all
these species are at risk of poisoning.
The migratory songbirds in most trouble include the wood thrush, the
Kentucky warbler, the eastern kingbird and the bobolink, celebrated by
the 19th century American poet Emily Dickinson as "the rowdy of
Bridget Stutchbury, an ornithologist and professor at York University
in Toronto, said: "With spring we take it for granted that the
sound of the songbirds will fill the air with their cheerful sounds.
But each year, as we continue to demand out-of-season fruits and
vegetables, fewer and fewer songbirds will return."
The bobolink songbird has experienced such a steep decline, it has
almost fallen off the charts. The birds migrate in flocks from
Argentina, Bolivia and Paraguay to the east coast of the US, feeding
on grain and rice, prompting farmers to regard them as a pest.
Bobolink numbers have plummeted almost 50 per cent in the past four
decades, according to the North American Breeding Bird Survey.
Rosalind Renfrew, a biologist who studied bobolinks as they were
feeding in rice paddies in Bolivia, found about half of the birds had
been exposed to toxic chemicals banned in Europe and the US. Some 40
to 50 species, which include the barn swallow, the wood thrush the
dickcissel as well as migratory birds of prey, are starting to
It is only recently that the decline has been definitively linked to
the use of toxic pesticides in the Caribbean and across Latin America.
"Everyone who has looked for pesticide poisoning in birds has
found it," Professor Stutchbury said. "When we count birds
during our summers we are finding significant population declines in
about three dozen species of songbirds."
She wrote in the comment pages of The New York Times: "They are
the modern-day canaries in the coal mine." She said: "The
imported fruits and vegetables found in our shopping carts in winter
and early spring are grown with types and amounts of pesticides that
would often be illegal in the United States."
Growers are using high doses of pesticides, which the World Health
Organisation calls class I toxins. These are also toxic to humans and
are either restricted or banned in the US and EU. But controls in
Latin American countries are easily flouted.
"I believe that if we don't make drastic changes quite literally
many birds which are common now are going to become rare," said
Testing by individual EU countries and the US Food and Drug
Administration reveals that fruits and vegetables imported from Latin
America are three and sometimes four times as likely to violate basic
standards for pesticide residues.