Ubiquitous presence of pesticides in feathers of common UK birds

Pesticides continue to be widely used despite the concerns about their negative impacts on non-target organisms. Birds are at risk from exposure to several classes of pesticides regardless of the habitats they are found in, since pesticides are applied in rural and urban areas. In some instances, the doses received have been found to cause lethal and/or sublethal effects. However, levels of pesticide exposure in wild birds remain largely unknown and this study aims to shed light on this matter. Feathers from five widespread bird species (blackbird Turdus merula, blue tit Cyanistes caeruleus, chaffinch Fringilla coelebs, dunnock Prunella modularis and goldfinch Carduelis carduelis) were collected from seven sites across the UK and Republic of Ireland from a variety of habitats. These were tested for the presence of 17 pesticides and 5 insecticide metabolites. All samples contained measurable levels of pesticides (> limit of quantification) and an average of four pesticides were present per sample. The most frequently occurring pesticides included the insecticides permethrin, chlorpyrifos, clothianidin and imidacloprid, and the herbicide pendimethalin. Permethrin was the most dominant pesticide present at all sites and in 98% of samples. These results highlight the prevalence of pesticide contamination using a non-intrusive method, which can be of value to monitor pesticide presence in the environment and flag up those of particular concern needing further investigation.