RT Journal Article T1 Assessing plastic ingestion in the White stork (Ciconia ciconia) through regurgitated pellets A1 Ramos Elvira, Elena A1 López García, Alejandro A1 Osorio, Laura A1 Colino Freire, Irene A1 Garcinuño Martínez, Rosa María A1 Fernández Hernando, Pilar A1 Aguirre De Miguel, José Ignacio AB Pollution is one of the main factors that threaten biodiversity nowadays. Plastic waste is a global problem which impacts not only on the marine environment but also on the terrestrial one. Great amounts of this kind of refuse are compiled in landfills, where lots of avian species feed. In contrast to seabirds research, there are limited studies that have considered how plastic is being ingested by land birds even when they are being affected both physically and at an endocrine level. We tried to assess the number of plastics and microplastics ingested by individuals of a White stork (Ciconia ciconia) colony in central Spain by collecting regurgitated pellets. The chemical composition of the elements was determined, as well as the relation between the amount of ingested plastic by individuals and their use of a landfill. Our results show that 3.44% of the pellet was formed by plastic (n = 50). Polyethylene, polystyrene, polypropylene and PET were the most abundant polymers, all of them being potentially problematic to the organism according to the literature. Each polymer was identified by Fourier transform infrared attenuated total reflectance spectroscopy (FTIR-ATR). We observed that the total amount of ingested plastics was stable along the use of the landfill, meaning White storks obtained plastic not only from anthropogenic sources but also from natural areas, indicating its high rate of pollution. Our study remarks the importance of addressing plastic ingestion in White storks as well as other terrestrial species, not only to understand the possible damage to the population but also to the whole ecosystem. PB Springer SN 0944-1344 YR 2025 FD 2025 LK https://hdl.handle.net/20.500.14352/118445 UL https://hdl.handle.net/20.500.14352/118445 LA eng NO Ramos-Elvira, E., López-García, A., Osorio, L. et al. Assessing plastic ingestion in the White stork (Ciconia ciconia) through regurgitated pellets. Environ Sci Pollut Res 32, 4502–4510 (2025). https://doi.org/10.1007/s11356-025-35956-w NO ERE was supported by the Funding Program of Complutense University of Madrid and Santander Bank (CT15/23). ALG was supported by the Funding Program of Complutense University of Madrid and Santander Bank (CT63/19-CT64/19). This paper is a contribution of JIA to the project: TED 2021-130043B-100. This work was supported by the National University of Distance Education (ALIPLASTIC-096–044030, 2023-PUNED-0013, 50ANIV GARCIN). NO Universidad Complutense de Madrid NO Banco de Santander NO Universidad Nacional a Distancia (España) DS Docta Complutense RD 25 abr 2025