Sublethal agrochemical residues in South African birds, 1969–2024

Abstract

Avian species serve as a barometer of ecosystem health and have been used to determine the presence of chemicals in the South African environment. We conducted a literature review to determine which sublethal agrochemical active ingredient residues have been tested for in South African bird species and which sample types were used. Seventy-three species in 37 publications spanning 55 years were identified, and most residue analyses were conducted on eggs. Fourteen insecticide active ingredients have been assessed, and only one is still legally used under restriction in South Africa. No active ingredients from fungicides or herbicides were determined. This emphasises the paucity of knowledge regarding the presence and sublethal effects of currently used agrochemicals on South African birds and the lack of information required to make informed regulatory decisions. Nearly 14 million hectares of South Africa’s land surface is used for crop cultivation, with continued expansion reported across the sector. Its associated agrochemical use accounts for 2% of the global volume. While the amount of agrochemicals used is concerning, the continued use of many highly hazardous chemicals banned elsewhere exacerbates the country’s pesticide challenges, highlighting the need for a more comprehensive environmental risk assessment scheme.