We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Wintering Thrushes as Microplastic Pollution Sentinels in the Ground-Foraging Guild of Mediterranean Olive Plantations
Summary
All 32 wintering thrushes examined from Mediterranean olive orchards contained microplastics, with juveniles carrying significantly higher loads than adults and redwings harboring more particles than song thrushes, confirming these birds as effective pollution sentinels even outside breeding ranges. The findings reveal that microplastic contamination is pervasive in terrestrial agroecosystems and enters wildlife food chains through ground foraging.
Plastic pollution is a growing global environmental problem, and evidence shows that many wildlife species ingest plastic. In terrestrial environments, thrushes are indicators of microplastics pollution within their breeding ranges. This study investigated whether the Song Thrush Turdus philomelos and Redwing Turdus iliacus can indicate plastic pollution in terrestrial environments during wintering, by analysing their digestive tracts. Thirty-two wintering individuals (16 per species) collected from olive tree orchards in Mediterranean Spain (northern Alicante province) were examined. All specimens contained plastics, yielding 326 microplastics classified as fibres (43.86%), films (35.89%) and fragments (20.24%). Dominant colours were blue (42.64%), red (25.50%), and black (13.80%). Redwings harboured significantly more microplastics (199 particles) in their gastrointestinal tracts than Song Thrushes (127 particles), with interspecific differences also evident in abundance, types, colours, and sizes. Juveniles showed significantly higher microplastics loads than adults across both species. These findings confirm thrushes as effective indicators of microplastic pollution, including in wintering areas, and highlight the ubiquity of these particles in terrestrial agroecosystems. Observed interspecific and age-related differences suggest distinct feeding strategies within the same wintering site, while the lack of pollutant accumulation in older birds indicates that migratory thrushes likely do not vector microplastics between European wintering and breeding grounds.