A controversial agricultural insecticide that has been implicated in the collapse of bee colonies around the world also appears to be causing bird populations to drop, according to a new study. The insecticides known as neonicotinoids are designed to attack the central nervous system of insects that devour crops, but only about 5 percent of the chemical compound stays on the plant. The rest leaches into the soil and water, where it does its magic on other bugs, the researchers said.
In areas with high loads of the pesticide, "insects in general are dropping dead, and therefore there is less food for the birds available to feed their offspring," said Caspar Hallmann, an ecologist and lead author of the paper published this week in Nature. Whatever the cause, bird populations are dropping at about 3.5 percent a year in farmland areas where surface-water concentrations of the neonicotinoid imidacloprid are high. At that rate, in 10 years bird populations could decline more than 30 percent.
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— John Roach, NBC News