Mercury in the feathers of Golden eagle (Aquila chrysaetos) from Western Carpathian, Slovakia

In this study, mercury (Hg) concentrations were detected in feathers of golden eagle (Aquila chrysaetos), a bird that typically inhabits alpine and forest areas. The mercury rates in feathers were compared in two groups of eagles: first, estimated home range (breeding, hunting, etc.) was located only in forest and lowland meadow habitats; second, the home range also included alpine habitats-rocks and meadows. Consequently, mercury concentration based on the feather typology were observed and the mercury levels in feathers were also compared among different Slovak Western Carpathian districts. It was found that there was no significant difference between groups classified by elevation level, which we attribute to the fact that eagle hunting territories are broad, so that alpine-dwelling and forest-dwelling eagles do not only reflect the pollution of the environments they typically inhabit. Non-significant differences were found also within different feather types, which means that the type of feather is not crucial for tracking mercury in eagle feathers. As the measurement of feather appears to be a simple and non-invasive method, the detection of non-significant differences in diverse types of golden eagle feathers provides useful knowledge for the future environment monitoring. The average mercury concentration measured in eagle samples was lower than the mercury concentration causing health complications among birds of prey. Our assumption that due to past mining activity in the Spiš region, the highest concentration in this region would be observed was confirmed.