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WASHINGTON (AP) - A British study suggests that the use of a new
biotech crop could lead to a steep decline in the population of the
skylark, a tuneful bird beloved in English poetry.
The study, appearing Friday in the journal Science, claims that
if most British farmers use a genetically altered sugar beet it
would deprive the skylark of weed seeds, a main source of food, and
cause the bird numbers to decline by up to 90 percent.
American agricultural researchers, however, say that conclusions
of the study are ``simplistic'' and highly questionable.
William J. Sutherland of the University of East Anglia in
Norwich, England, said he and colleagues believe that gene-altered,
herbicide-resistant sugar beets will allow British farmers to use
more powerful plant-killing sprays and more effectively control
weeds in their fields.
But the weeds, said Sutherland, produce seeds that are a mainstay
of the skylark diet.
``If you measure the abundance of skylarks in some fields, one
finds that could be explained by the abundance of seeds in those
fields,'' said Sutherland. Using the herbicide-resistant beets
``means more herbicides, which means fewer weeds, fewer seeds and
fewer skylarks,'' he said.
The finding strikes a strong emotional cord among bird lovers in
the United Kingdom, where genetically altered food crops already are
viewed with suspicion.
The skylark has ordinary plumage - brown with tan and white
stippling - but it is celebrated in poetry for its crystal song,
often trilled by a love-struck male hovering high above the ground.
Poet Percy Bysshe Shelley begins his ode ``To a Skylark'' with the
famous words: ``Hail to thee, blithe spirit!'' and tells of the joy
of hearing the bird's ``shrill delight.''
Despite its popularity, the skylark's population in England has
declined by 52 percent since 1970 because of intensified farming,
Sutherland said. He said the use of gene-altered beets threatens to
accelerate that decline.
But American researchers strongly rejected the skylark study over
what call a lack of thoroughness and a heavy dependence on theory
and assumptions.
``This research is a bit simplistic and it does not help to
resolve the issues,'' said Bill Palmer, a research scientist at the
Tall Timbers Research Station in Tallahassee, Fla.
Palmer said the British study is based on a computer model and
lacks proof that can only come from field research. He said some
American research has shown that growing herbicide-resistant crops
actually provides more food for birds.
Palmer said farmers using the crops tend to leave more stubble on
the surface of their fields, since they don't have to plow to
control weeds, and that this promotes an increase in worms and other
insects that birds eat.
But Palmer admitted that ``the jury is still out'' about how
genetically altered crops will affect the environment.
In a Science analysis of the study, Les G. Firbank of the Centre
for Ecology and Hydrology in England and Frank Forcella of the
University of Minnesota said that the conclusion by Sutherland and
his colleagues ``is questionable in light of experiences with
growing (gene-altered herbicide-resistant) maize, soybeans, canola
and sugar beet in the United States.''
The biotechnology industry has altered a number of food and fiber
plants by inserting genes that provide some apparent benefit. For
instance, some types of corn have been altered to naturally produce
a toxin that kills insects that feed on the plant, thus reducing the
need for insecticide spraying. A rice strain has been altered to
provide more vitamin A, which is seriously lacking in some Asian
diets.
The beets cited by Sutherland and his colleagues have been
genetically altered to be resistant to herbicides. This allows
farmers to use more powerful plant-killing chemicals to control
weeds because the spray will not harm the crops.
At least two studies have shown that pollen from the gene-altered
corn is toxic to monarch butterfly larvae that feed on milkweeds
growing beside corn fields. Others have questioned the proven safety
of genes that modify the nutrition of certain plans.
These concerns have prompted England and some other countries in
Europe to severely restrict growing and selling of gene-altered farm
crops.
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