Monitoring of raptors and their contamination levels in Norway.
This article summarizes results from raptor monitoring and contamination studies in Norway of the golden eagle, gyrfalcon, white-tailed sea eagle, osprey, peregrine, and merlin. Golden eagle and gyrfalcon populations have been monitored since 1990 as part of the "Monitoring Programme for Terrestrial Ecosystems" (TOV). No long-term trend in the population size or productivity of golden eagle has been shown in any of the 5 study areas. The reproductive output of gyrfalcon is monitored in 3 areas. It is positively correlated with the populations of its main prey species, the rock ptarmigan and the willow ptarmigan. The white-tailed sea eagle population has been monitored since 1974 by the Norwegian Ornithological Society, and the population is increasing. The levels of pesticides and polychlorinated biphenyls are low in the eggs of both the golden eagle and the gyrfalcon, but elevated levels and effects on reproduction have been indicated for a coastal subpopulation of golden eagle. The pollutant levels in white-tailed sea eagle are lower than in the Baltic population of sea eagles, and shell thinning was never severe overall, but individual eggs have contained pollutant concentrations above critical levels. The levels of pollutants in the bird-eating falcons, peregrine, and merlin were higher than in other species. New emerging pollutants, like brominated diphenylethers and perfluorinated organic compounds, could be detected in all species. By incorporating available published and unpublished data, we were able to produce time trends for pollutants and shell thickness over 4 decades.
Gjershaug
Jan Ove
JO
Norwegian Institute for Nature Research, Trondheim, Norway. jan.o.gjershaug@nina.no
Kålås
John Atle
JA
Nygård
Torgeir
T
Herzke
Dorte
D
Folkestad
Alv Ottar
AO
D000818:Animals; D004784:Environmental Monitoring / Q000331:legislation & jurisprudence / Q000379:methods / Q000706:statistics & numerical data; D004785:Environmental Pollutants / Q000032:analysis* / Q000493:pharmacokinetics / Q000633:toxicity; D020387:Food Chain; D009664:Norway; D010063:Ovum / Q000187:drug effects / Q000378:metabolism; D011157:Population Dynamics; D020304:Raptors / Q000254:growth & development* / Q000378:metabolism; D012098:Reproduction / Q000187:drug effects
D004785:Environmental Pollutants