European hares as bioindicators of glyphosate exposure: A multi-year assessment of urinary residues

Glyphosate (GLY) is the world’s most widely used herbicide, yet direct observations of GLY and its primary metabolite aminomethylphosphonic acid (AMPA) in wild mammals remain scarce. We analyzed 155 composite urine samples from European hares ( Lepus europaeus ) collected across agricultural regions between 2016 and 2024 to assess concentrations and temporal trends of GLY and AMPA. Annual median GLY concentrations ranged from 1.21 to 3.50 µg L⁻¹ , with no significant trend over time. AMPA represented on average 18 % of GLY levels. Extremely high GLY concentrations (>100 µg L⁻¹) were rare but observed, while most of the observed concentrations were< 0.5 L −1 . Annual medians correlated significantly with reported national GLY consumption (p < 0.05). Urinary GLY in hares was approximately 3–4 times higher than the mean concentrations reported in human populations. These findings highlight the utility of European hares as bioindicators of GLY exposure in agroecosystems and emphasize the need for continued monitoring of herbicide residues in wildlife to better understand environmental contamination pathways and potential risks to ecosystems.