The effects of low levels of pollutants on the reproduction of golden eagles in western Norway thanks

The reproductive success of golden eagles was studied in an area in western Norway between 62 degrees and 63 degreesN between 1973 and 1999. Addled eg gs were collected for analysis of chemical pollutants from nine territories ; five from coastal areas and four from inland. The coastal sites had lower annual reproductive output than inland sites, and the eggs had a higher co ntent of organochlorine compounds. There were relatively strong negative co rrelations between reproductive output and (1) shell thickness and (2) DDE concentration in eggs. The data indicate that the golden eagle may be a par ticularly sensitive species to DDE. It is proposed that the higher organoch lorine content found in the eggs of coastal birds was caused by a contribut ion of marine birds to the diet, as opposed to inland eagles which have a p rey basis consisting almost entirely of terrestrial herbivores such as grou se, mountain hare and cervids. Our data-set on reproductive output is, howe ver, too small to establish a general relationship between DDE contaminatio n and reproductive output in golden eagles.