Environmental contamination by veterinary medicinal products and their implications in the conservation of the endangered Pyrenean Capercaillie (Tetrao urogallus aquitanicus)

The endangered Pyrenean Capercaillie (Tetrao urogallus aquitanicus) inhabits perennial forests of the Pyrenees (Spain, France and Andorre). Feces of domestic animals (e.g., horses and cattle) are often found in this species’ habitat as evidence of land use overlapping, especially during spring and summer. As a result, pharmaceutical residues found in feces of these domestic ungulates may be absorbed by plants and insects that are part of the diet of Pyrenean Capercaillies (e.g., blueberries [Vaccinium uliginosum, Vaccinium myrtillus], red wood ants [Formica rufa]). Based on the absence of data regarding the exposure of Pyrenean Capercaillie to residues of veterinary medicinal products (VMP), we selected 71 compounds as indicators of anthropogenically-related environmental contamination, analyzed in 90 samples collected in several subalpine forests, northwestern Spain. Residues of several VMP were detected in feces (capercaillie [ciprofloxacin, enrofloxacin, tetracycline and florfenicol], horse [ciprofloxacin, enrofloxacin, tetracycline and ivermectin], and cattle [ciprofloxacin and enrofloxacin]), and in entomofauna (ciprofloxacin and ivermectin). No VMP residues were detected in blueberry plants. Herein, we present novel data about the presence of VMP residues in the Pyrenean Capercaillie’s environment, and identify potential VMP sources (i.e., livestock feces and entomofauna) and an exposure route (i.e., food chain) for Capercaillie chicks. Further studies are necessary to investigate the potential indirect or chronic effects of VMP residues in the species’ breeding success and adult fitness, which must be taken into account by managers and policy makers to improve management and conservation actions.