One of the most widely used fungicides in farming harmful to reproduction in birds

A French team coordinated by a scientist at CNRS¹ highlights the harmful impact on sparrow reproduction of chronic exposure to tebuconazole, one of the most widely used fungicides in agriculture in Europe. These findings, recently published in Environmental Research, reveal a direct link between exposure to this fungicide and slower growth, as well as increased mortality, in sparrow chicks, with a greater impact on females.

Research had already pointed to intensified agriculture and the related use of herbicides and insecticides such as glyphosate as the reason for a decline in farmland birds for several decades. The impact of fungicides, used to control mildew and powdery mildew, however, remained poorly studied.

Scientists compared breeding performance in a control group of domestic sparrows and a group exposed to tebuconazole at realistic concentrations. While exposure to the fungicide had no effect on the health, breeding period, number of eggs laid or hatching success of birds in the second group, harmful effects were observed in chicks after hatching. Chicks in the exposed group, and in particular females, showed reduced growth (about 10% smaller) and a higher – doubled – mortality rate after leaving the nest (47% compared to 20% in the control group).

Further studies are needed to better document the contamination of wild animals by this substance and its potentially harmful physiological effects.

1 – From the Centre for Biological Studies of Chizé (CNRS/ Université La Rochelle) and the Laboratoire Chrono-Environnement (CNRS/Université Marie et Louis Pasteur).