Researchers have identified two pesticides that are making songbirds severely ill. Pesticides known as neonicotinoids and organophosphates, which are among the most widely used in the world, have been previously linked to declining bee populations.
Now, biologists have witnessed firsthand just how harmful the pesticides are for birds as well.
A study by researchers at the University of Saskatchewan is unprecedented in demonstrating the toxic effects of neonicotinoids and organophosphates in birds. The research team fed sparrows varying doses of the pesticides over the course of three days during spring migration.
The experts found that the birds suffered from drastic weight loss and completely lost their sense of direction after ingesting only three or four seeds affected by an insecticide in the class of neonicotinoids known as imidacloprid.
“What surprised us was how sensitive and rapid the effects were, particularly to imidacloprid,” said study co-author Christy Morrissey. “The birds showed a significant loss of body mass and signs of acute poisoning (lethargy and loss of appetite).”
“The migration trials also showed that birds completely failed to orient or changed their northward orientation,” said Morrissey.
Study co-author Margaret Eng said that the team found it encouraging that most of the birds observed in the study recovered after they stopped ingesting the pesticides.
“But the effects we saw were severe enough that the birds would likely experience migratory delays or changes in their flight routes that could reduce their chance of survival, or cause a missed breeding opportunity,” said Eng.
According to Morrissey, the findings of this study could have a major impact on the regulation of these pesticides.
The research is published in the journal Scientific Reports.
By Chrissy Sexton, Earth.com Staff Writer