A new study has confirmed that pesticides kill songbirds and could be responsible for the decline in populations. In fact, three BILLION birds have been lost in North America since 1970.
Experiments showed that the controversial neonicotinoid class of insecticides turn birds “anorexic”, rapidly reducing their body weight and interrupting their migratory schedule.
Neonicotinoids, the most widely used class in the world, were banned for outdoor use across Europe last year due to concerns about their impact on bees.
RELATED STORY:
However, little is known about the danger posed to other species.
In the first ever study of its kind, scientists at the universities of York and Saskatchewan fed seeds sprayed with the pesticide to white-crowned swallows who paused during their migration in agricultural land to feed.
RELATED STORY:
This caused them to lose up to six per cent of their body mass within just six hours, delaying them up to three and a half days longer at the stopover site compared to birds not exposed to the neonicotinoids.
Even a small delay can significantly hamper a bird’s chances of finding a mate.
RELATED STORY:
Authors of the new study, published in the journal Science, say the widespread use of neonicotinoids may be partly behind the steep decline in populations of migratory birds over recent years.
Co-authors of the study, Dr. Bridget Stutchbury and Margaret Eng said:
“Our study shows that this is bigger than the bees: birds can also be harmed by modern neonicotinoid pesticides which should worry us all. We saw these effects using doses well within the range of what a bird could realistically consume in the wild, equivalent to eating just a few treated seeds.”1
Because the researchers used controlled dosing, they were able to confirm a cause and effect between neonicotinoid exposures and delayed migration, not just a correlation that is more typical of field studies.
RELATED STORY:
Environmentalists already suspected that pesticides was indirectly harming avian populations by killing insects which provide a source of food for birds.
The use of neonicotinoids have been restricted in some states in the USA, but clearly more need to be done.
