Postdoctoral researcher in ecotoxicology Pauline Bellot is among the three winners for the month of January 2026 of the Relève star competition of the Fonds de recherche du Québec (FRQ). This competition promotes careers in research and aims to recognize the excellence of the work carried out by university-level students, in all disciplines of the three sectors covered by the FRQ: Nature and technologies, Society and culture and Health.
Pauline Bellot won the Louis-Berlinguet prize, accompanied by a $1,500 grant, for the article entitled “Chronic exposure to tebuconazole impairs offspring growth and survival in farmland birds: An experiment in captive house sparrows» published in Environmental Research. The postdoctoral student is the first author of the article, co-signed with researchers from CNRS-La Rochelle University and the University of Franche-Comté.
This study focuses on the impact of pesticides on bird populations living in European agricultural environments, which have fallen by more than 60% over the last 40 years. Among these substances, triazoles are a family of widely used fungicides, used to protect many crops against fungi, notably vines and cereals. However, these products remain largely understudied, because they are often considered less toxic than other categories of pesticides, such as insecticides. However, they could have negative effects on birds, by disrupting their physiological mechanisms and their reproduction.
To better understand these impacts, Pauline Bellot and her colleagues conducted a captive experiment on the house sparrow, a species representative of agricultural areas. Realistic conditions were reproduced by administering tebuconazole, one of the most widely used fungicides in agriculture, at concentrations similar to those measured in the blood of wild birds living near vineyards. The concentration chosen was 36 times lower than the toxicity thresholds officially established for birds, in order to evaluate potential effects at low doses. The fungicide was distributed in drinking water for nine months, including the breeding period, to test long-term chronic effects.
The study compared two groups housed in large outdoor aviaries subject to natural weather conditions: an exposed group, in three aviaries receiving water containing tebuconazole, and a control group, placed in three identical aviaries receiving water devoid of this fungicide.
Several indicators of reproductive performance were then evaluated, such as the number of eggs laid, hatching rate, growth and survival of chicks. The results show that although the number of eggs and hatching rate were not affected, the growth of exposed chicks was lower (10% smaller on average) and their mortality significantly increased. These effects were even more marked in females: 65% of exposed female chicks died before fledging, compared to only 7% in the control group. This difference by sex is particularly important, because it suggests that females are more sensitive to contamination and that exposure could lastingly affect population structure.
This study demonstrates that tebuconazole can harm the reproduction of birds in agricultural environments, even at doses considered low and realistic. It highlights the urgency of better assessing the risks associated with these fungicides and of understanding more precisely their direct (toxicity on the embryo and chick) and indirect (egg quality and parental care) effects.
date:2026-02-11 18:58:00
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