Active monitoring of long-eared owl (Asio otus) nestlings reveals widespread exposure to anticoagulant rodenticides across different agricultural landscapes.

Autor: Spadetto L; Toxicology Research Group, Faculty of Veterinary, Campus de Espinardo, University of Murcia, 30100 Murcia, Spain., Gómez-Ramírez P; Toxicology Research Group, Faculty of Veterinary, Campus de Espinardo, University of Murcia, 30100 Murcia, Spain. Electronic address: pilargomez@um.es., Zamora-Marín JM; ULULA Association for Owl Study and Conservation, 30100 Murcia, Spain; Department of Applied Biology, Centro de Investigación e Innovación Agroalimentaria (CIAGRO-UMH), Miguel Hernández University of Elche, Elche, Spain; Department of Zoology and Physical Anthropology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain., León-Ortega M; ULULA Association for Owl Study and Conservation, 30100 Murcia, Spain., Díaz-García S; ULULA Association for Owl Study and Conservation, 30100 Murcia, Spain., Tecles F; Interdisciplinary Laboratory of Clinical Analysis (Interlab-UMU), Veterinary School, Regional Campus of International Excellence 'Campus Mare Nostrum', University of Murcia, 30100 Murcia, Spain., Fenoll J; Instituto Murciano de Investigación y Desarrollo Agrario y Alimentario, IMIDA, 30150 Murcia, Spain., Cava J; Instituto Murciano de Investigación y Desarrollo Agrario y Alimentario, IMIDA, 30150 Murcia, Spain., Calvo JF; Department of Ecology and Hydrology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain., García-Fernández AJ; Toxicology Research Group, Faculty of Veterinary, Campus de Espinardo, University of Murcia, 30100 Murcia, Spain.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 Mar 25; Vol. 918, pp. 170492. Date of Electronic Publication: 2024 Feb 01.
DOI: 10.1016/j.scitotenv.2024.170492
Abstrakt: The widespread use of anticoagulant rodenticides (ARs) poses a worldwide threat to farmland wildlife. These compounds accumulate in tissues of both target and non-target species, potentially endangering both direct consumers and their predators. However, investigations on ARs in blood of free-ranging predatory birds are rare. Here, the long-eared owl (Asio otus) has been used as a model predator to assess AR exposure in different agricultural landscapes from a Mediterranean semiarid region. A total of 69 owlets from 38 nests were blood-sampled over 2021 and 2022, aiming to detect AR residues and explore factors that determine their exposure, such as land uses. In addition, prothrombin time (PT) test was conducted to assess potential effects of AR contamination. Overall, nearly all the samples (98.6 %) tested positive for at least one compound and multiple ARs were found in most of the individuals (82.6 %). Among the ARs detected, flocoumafen was the most common compound (88.4 % of the samples). AR total concentration (ΣARs) in blood ranged from 0.06 to 34.18 ng mL -1 , detecting the highest levels in the most intensively cultivated area. The analysis of owl pellets from 19 breeding territories showed relevant among-site differences in the contribution of rodents and birds into the diet of long-eared owls, supporting its high dietary plasticity and indicating AR presence at multiple trophic levels. Moreover, a positive and significant correlation was found between ΣARs and PT (Rho = 0.547, p < 0.001), which demonstrates the direct effect of ARs on free-living nestlings. Our results provide a preliminary overview of AR exposure in a little-studied owl species inhabiting agricultural and rural landscapes. Despite the low detected levels, these findings indicate widespread exposure -often to multiple compounds- from early life stages, which raises concern and draws attention to an ongoing and unresolved contamination issue.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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