engleski

Analyses on Macro and Microplastic Particles in Pellets of White Stork (Ciconia ciconia) From Croatia

Plastic pollution is an emerging concern, swiftly increasing in terrestrial ecosystem due to anthropogenic activities. Ingestion of plastic fragments (and other anthropogenic particles) is of special concern due to detrimental effects on apex predators, especially those with opportunistic dietary habits. White storks (Ciconia ciconia) are known to forage on agricultural fields, wetlands and grasslands searching for diverse prey (e.g. fish, amphibians, reptiles, small mammals, insects and earthworms). Anthropogenic particles, macro- (> 5 mm) and microplastic (< 5 mm), were analysed from white stork regurgitated pellets as they were collected from the nest during breeding season 2020 in continental Croatia. In addition to plastic content analysis, feeding ecology was evaluated by assessing variation in diet composition. Pellets were dried at 70 °C for 24 h, weighted on analytical scale to 0.001 g and dissected. Prey remains were identified based on morphological characteristics. The largest component of dry pellets was remains of small mammals (fur) and remains of exoskeletons from grasshoppers (Orthoptera) and beetles (Coleoptera). Macro and/or microplastic particles were visually detected with a high-quality stereomicroscope. Separated macro- and microplastic were subsequently confirmed with hot needle method. Secondary microplastic is predominantly found as it is degraded from the larger plastic. Most of microplastic found in the pellets are clear fragments, 0.5 - 4 mm in diameter (mean = 2.40 mm, SD = 1.77), while most macroplastic found in the pellets are filaments, 6 - 40 mm (mean = 19.63, SD = 11.16). Microplastic smaller than 0.5 mm was detected with light microscope based on shape, colour and pattern. Other anthropogenic particles can be present in the pellets such as glass and building material used for construction. This is the first study assessing plastic content in the regurgitated pellets from terrestrial apex predators - white storks.

pellets ; microplastic ; macroplastic ; white stork ; Croatia

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