New research carried out has deemed that neonicotinoids are having a strange effect on migrating birds, causing them to lose their minds, as reported by the Guardian.
As a result of the insecticide, songbirds were found to have lost their sense of direction and began suffering severe weight loss. This is the first evidence published, which highlights the dangers of the insecticide to wild birds during migration. It also adds to the recent increased research and studies into the dangers of the insecticides to wildlife other than bees.
Pesticides have been long blamed for the decline in farmland bird numbers, especially in Europe and North America. Now it seems there is definitive proof, though a team of researchers in the Netherlands in 2014, found similar results. They found that bird populations fell drastically, in times of peak neonicotinoid use. It found that sparrows, starlings and swallows were among the worst affected.
The new study was carried out at the University of Saskatchewan, Canada, with the lead professor professing her shock at the results.
“The reason our new study is special is this is not a correlation – it is actual experimental evidence,” said Prof Christy Morrissey.
“The effects were really dramatic. We didn’t anticipate the acute toxicity, because the levels [of neonicotinoid] we gave them were so low.” she added.
The news comes after three insecticides were banned from use on flowering crops in the EU over 4 years ago. This was put down to the adverse effect it had on bee populations and other pollinators. A total outdoor ban is now being considered, while Canada are now also considering banning neonicotinoids in their entirety.
Research showed that decreasing use of neonicotinoids would result in reduced food production on almost every farm. This latest research was carried out on the effect of the insecticide, neonicotinoid imidacloprid, on white-crowned sparrows. Birds were given a small dose of the chemical, the size of a corn seed, and within hours the results became apparent.
Not long after the birds began getting weak, developing stomach issues and stopped eating. Within hours they lost almost one-quarter of their body weights, whilst they also had no sense of direction and were disorientated.
“Basically, these birds became lost,” said Professor Morrissey.
The team also used control birds, which received none of the insecticide, which were left unaffected. Almost two weeks after been given the dose, the birds recovered their weight and regained their sense of direction.
We know from other studies on many different species of migratory birds that if you are delayed by even a few days getting to your breeding ground, or you are in poor condition when you arrive, you have lower reproductive success. We know these effects are really important for population level changes.” said Morrissey.
It is thought that wild birds eat seeds, which generally has neonicotinoids applied to them, meaning bird numbers could be taking a huge hit. A study carried out by the Minnesota Dept of Natural Resources found that seeds were common food amongst birds and other wildlife.
“Everything from pheasant to blackbirds, house sparrows, deer, raccoons, bunnies, mice, squirrels. Lots of different animals are coming to the spills,” said Charlotte Roy of the Minnesota Dept of Natural Resources.
Head of the original study, Morrissey, admitted that seed sowing comes at the same time as birds migrating north.
“They [the pesticides] are applied in spring which exactly overlaps the time when they are moving through these areas and many are stopping in agricultural fields to refuel along the journey.” said Morrissey.
“Scientific evidence shows that imidacloprid has minimal environmental impact when used according to the label, including ingestion by seed-eating songbirds. We take the safety and environmental impact of our products seriously.” said a spokesperson for Bayer, the company behind the imidacloprid.
The spokesperson said birds tend to remove the hull of the seed, which is where insecticide is applied. He also suggested that birds were never exposed themselves to such high volumes as those received by the birds in the study.
The team of researchers will now begin measuring the levels of the insecticide in the bird’s’ blood, while also analyzing data from radio-tagged birds given smaller doses. They have noted already that even small doses have had an effect.
“Pesticides have long been speculated as being one of the drivers of farmland bird declines, but we are only just barely touching the edge of that and understanding how pesticides can affect birds.” concluded Morrissey.