Lead poisoning and other human-related factors cause significant mortality in white-tailed eagles

• Published in: Ambio
• Main Authors: Isomursu, M., Koivusaari, J., Stjernberg, T., Venäläinen, E.-R., Hirvelä-Koski, V.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer 2018
• Subjects: Finland; lead poisoning; mercury; mortality factors; White-tailed eagle; Haliaeetus albicilla
• Online Access: http://hdl.handle.net/10138/275001

The white-tailed eagle (Haliaeetus albicilla) suffered a severe population decline due to environmental pollutants in the Baltic Sea area ca. 50 years ago but has since been recovering. The main threats for the white-tailed eagle in Finland are now often related to human activities. We examined the human impact on the white-tailed eagle by determining mortality factors of 123 carcasses collected during 2000-2014. Routine necropsy with chemical analyses for lead and mercury were done on all carcasses. We found human-related factors accounting for 60% of the causes of death. The most important of these was lead poisoning (31% of all cases) followed by human-related accidents (e.g. electric power lines and traffic) (24%). The temporal and regional patterns of occurrence of lead poisonings suggested spent lead ammunition as the source. Lead shot was found in the gizzards of some lead-poisoned birds. Scavenging behaviour exposes the white-tailed eagle to lead from spent ammunition.