Mercury concentrations in daytime birds of prey in Portugal

• Autor(a) principal: Ascenção, Sandra Raquel Oliveira
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/28379
• topic: Trace metal; Contamination; Bbiomonitoring; Raptors; Food web

Mercury is one of the most harmful non-essential elements to wildlife for its ability to bioaccumulate and bioamplify throughout the food chain. Due to the continuous increase in concentration of this element, birds of prey are often used as biomonitors due to their wide habitat diversity and high probability of contaminant accumulation as top predators. In the present work, the concentration of mercury in 10 tissues (nails, beak, feathers, liver, kidneys, lungs, heart, muscle, brain and skin) of four birds of prey was analyzed: common buzzard (Buteo buteo) , eurasian sparrowhawk (Accipiter nisus), common kestrel (Falco tinnunculus) and little owl (Athene noctua) and evaluated the influence of parameters such as gender and age on the accumulation of this element. The results showed significant differences between tissues in the order of concentrations: skin < brain< muscle < heart < lungs < liver < kidneys < feathers < nails < beak. Significant differences were observed between the different species, in which the eurasian sparrowhawk and the common buzzard presented the highest values. The age group influenced the accumulation in the common kestrel, where subadults presented higher values than those shown in adults, with no differences regarding gender. For the remaining bird species no significant differences were identified for variation of accumulation with gender or age.