Science News

Friday September 1 2:40 AM ET

      Biotech Crops May Reduce Bird Food

 

      By PAUL RECER, AP Science Writer

 

      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.