Spatial variation of mercury levels in nesting Bonelli's eagles from Southwest Portugal: effects of diet composition and prey contamination. | - CCMAR -

Journal Article

TitleSpatial variation of mercury levels in nesting Bonelli's eagles from Southwest Portugal: effects of diet composition and prey contamination.
Publication TypeJournal Article
AuthorsPalma, L, Beja, P, Tavares, PC, Monteiro, LR
Year of Publication2005
JournalEnviron Pollut
Volume134
Issue3
Date Published2005 Apr
Pagination549-57
ISSN0269-7491
KeywordsAnimals, Diet, Environmental Pollutants, Female, Food Contamination, Male, Mercury, Nesting Behavior, Portugal, Predatory Behavior, Raptors
Abstract

Mercury (Hg) was determined in adult Bonelli's eagles (Hieraaetus fasciatus) and their avian prey, from samples of feathers collected between 1992 and 2001 at the nesting sites of 21 pairs in Southwest Portugal. Eagle Hg levels showed great variation, reflecting primarily differences in diet composition and food chain biomagnification. Concentrations were positively correlated with the dietary proportion of insectivorous and omnivorous birds (e.g. egrets, corvids and thrushes), with very low levels for pairs feeding mainly on herbivores (e.g. rabbits, pigeons and partridges). Differences in prey contamination among breeding territories added to dietary effects in determining variation of Hg levels in eagles, shaping a spatial pattern that was largely consistent with a source of contamination in a coal-burning power-plant lying upwind of the study area. Despite this presumed contamination, Hg levels seemed to be of little concern to this eagle population, though there might be subtle deleterious effects on the reproductive output of a few pairs. This study emphasizes the need to account for dietary effects when biomonitoring Hg contamination using birds of prey.

DOI10.1016/j.envpol.2004.05.017
Sapientia

http://www.ncbi.nlm.nih.gov/pubmed/15620600?dopt=Abstract

Alternate JournalEnviron. Pollut.
PubMed ID15620600
CCMAR Authors