Neonicotinoid pesticides are linked to decline in bird biodiversity

Neonicotinoid pesticides remain controversial as evidence mounts to show their detrimental impacts on important biodiversity. Documenting more evidence of their harm, a recent study in the journal Nature Sustainability found that neonicotinoid use in agricultural areas correlated with significant declines of birds. Non-grassland and non-insect-eating birds were impacted the least with a 2% reduction, but populations of grassland and insect-eating birds experienced reductions of 4% and 3% respectively. This makes sense given the way that neonicotinoids work. Neonicotinoid pesticides are systemic, meaning that they are absorbed by the plant and distributed throughout its tissue. When an insect feeds on that plant tissue, it also consumes the pesticide and is killed. These pesticides are argued to be more sustainable than other topically sprayed pesticides because they won’t run off with rain and can remain effective in the plant longer than topical pesticides so the number of repeat spraying event is reduced. However, the toxicity of neonicotinoids has been shown to affect non-targeted insects and animals who either directly eat the plant tissue, like honeybees who eat contaminated nectar and pollen, or indirectly when they eat insects that have ingested neonicotinoid contaminated plant tissue. This study offers more data to the growing body of science that demonstrates the unintended consequences of systemic pesticides. While many continue to push for the ban of neonicotinoid use, these chemicals are not allowed in organic agriculture and instead, organic farmers rely on other pest control tools that help protect important and beneficial biodiversity.


Banner Photo Credit: Kevin Grieve;