Concentration of toxic and essential elements in livers of birds of various foraging guilds collected during the autumn migration period in Poland

Abstract

Abstract During migration, birds explore various habitats at stopover sites that differ in food resources and contamination levels. In this study, hepatic concentrations of 21 elements in 11 species of birds, representing various foraging guilds (omnivores, piscivores, molluscivores) and migration modes (migratory, sedentary), were analyzed. The samples were collected during the autumn migration period in Poland. The concentrations of elements determined in this study exhibited high inter-species variability, reflecting the diversity of food resources used by specific bird groups and their contamination levels. Many of the investigated individuals from different species showed exceeded levels of subclinical toxicity and moderate clinical poisoning due to Cd and Hg. The data collected confirmed the limited ability of As to enter ecosystem pathways. This study suggests that measuring hepatic elemental concentrations can help detect environmental contamination at stopover sites used during migration and identify the key contaminants that can impact avian health during this period. The presented results contribute significantly to understanding the year-round exposure of migratory birds to environmental contamination.