Origins of organochlorines accumulated by peregrine falcons, Falco peregrinus, breeding in Alaska and Greenland

Differential productivity among populations of Peregrine Falcons breeding in Greenland and in Arctic and interior Alaska was found to be closely associated with DDE levels in unhatched eggs and in the lipids of eggshell membranes. Relatively higher levels of dieldrin in Arctic Alaska and of mirex in interior Alaska, compared to DDE, indicated regional differences in exposure, either in South America, or through the consumption on the breeding grounds of migrant prey species. The general features of the "fingerprint" profile of organochlorine contaminants throughout Alaska and Greenland, however, were markedly different from the profile of the same synthetic organochlorines measured in unhatched eggs of Peregrine Falcons breeding in California, where several of the organochlorine insecticides are no longer used.