A neonicotinoid insecticide reduces fueling and delays migration in songbirds

Abstract

Neonicotinoids are neurotoxic insecticides widely used as seed treatments, but little is known of their effects on migrating birds that forage in agricultural areas. We tracked the migratory movements of imidacloprid-exposed songbirds at a landscape scale using a combination of experimental dosing and automated radio telemetry. Ingestion of field-realistic quantities of imidacloprid (1.2 or 3.9 milligrams per kilogram body mass) by white-crowned sparrows (Zonotrichia leucophrys) during migratory stopover caused a rapid reduction in food consumption, mass, and fat and significantly affected their probability of departure. Birds in the high-dose treatment stayed a median of 3.5 days longer at the site of capture after exposure as compared with controls, likely to regain fuel stores or recover from intoxication. Migration delays can carry over to affect survival and reproduction; thus, these results confirm a link between sublethal pesticide exposure and adverse outcomes for migratory bird populations.

Neonicotinoids disrupt memory, circadian behaviour and sleep

“…However, few precursive safety tests were performed on beneficial insects, for which neonicotinoids are now known to be potent neurotoxins with well-documented lethal and sub-lethal effects 11,15,17,18,19 . Therefore, continued intensive use is likely to have severe consequences on insect species numbers, with knock-on effects for the ecosystem, aquatic life, birds and mammals in addition to potential toxicity to humans 11,[20][21][22] . Despite the recent European Union (EU) ban of three major neonicotinoids (the nitroimines: imidacloprid, clothianidin and thiamethoxam, the latter being a prodrug for clothiandin 23 ), neonicotinoids remain the most widely used class of insecticide globally, with a number of studies showing there has been no decrease in the quantity of banned neonicotinoids found in different populations of honey and bumble bee across Europe a year after the ban 24,25 .…”

Uptake, Metabolism, and Elimination of Fungicides from Coated Wheat Seeds in Japanese Quail (Coturnix japonica)

“…16,18,24 White-crowned sparrows (Zonotrichia leucophrys) dosed with imidacloprid at environmentally relevant levels failed to return to a northbound orientation following exposure and experienced induced mass loss, reduced feeding, and extended stopover durations. 19,26 Japanese quail (Coturnix japonica) dosed with imidaclopridtreated wheat seeds at 3 and 9% of the median lethal dose (LD 50 ) exhibited sublethal effects on behavior and physical performance. 21 In comparison to insecticides, fewer studies have assessed the effects of seed treatment fungicides on avian species.…”

Efeitos à saúde por exposição ambiental e ocupacional aos pesticidas de uso agrícola

“…Os neonics já foram relacionados a impactos generalizados em populações de abelhas (Sánchez-Bayo et al, 2016), aves (Eng et al, 2019;Stanton et al, 2018) e invertebrados aquáticos (Morrissey et al, 2015).…”

“…As aves podem se expor aos pesticidas agrícolas pelo contato com os gases e vapores das pulverizações, ingestão de insetos, água e solo contaminados e consumo de sementes tratadas (Eng et al, 2019). Aves migratórias que usam áreas agrícolas para reabastecimento foram expostas a pequenas quantidades de imidaclopridoum neonicotinóidee apresentaram diminuição no consumo de alimentos, massa e gordura corporal, atrasos na perda de peso e migração, o que pode reduzir suas chances de reprodução e sobrevivência (Eng et al, 2019).…”

“…As aves podem se expor aos pesticidas agrícolas pelo contato com os gases e vapores das pulverizações, ingestão de insetos, água e solo contaminados e consumo de sementes tratadas (Eng et al, 2019). Aves migratórias que usam áreas agrícolas para reabastecimento foram expostas a pequenas quantidades de imidaclopridoum neonicotinóidee apresentaram diminuição no consumo de alimentos, massa e gordura corporal, atrasos na perda de peso e migração, o que pode reduzir suas chances de reprodução e sobrevivência (Eng et al, 2019). Além dos efeitos letais e subletais dos pesticidas, outros fatores relacionados à agricultura, como a transformação e perda de habitats naturais, interferência de equipamentos agrícolas e redução da oferta de alimentos (especialmente para aves insetívoras), podem explicar parcialmente por que algumas espécies de aves estão diminuindo drasticamente em todo o mundo (Stanton et al, 2018).…”