Organochlorine contaminants in a terrestrial foodweb on the Niagara Peninsula, Ontario, Canada 1987-89

Concentration of organochlorine pesticides were measured in the eggs of four bird species, including kestrel, robin, bluebird, and starlings in Ontario, Canada from 1987 to 1989. The same compounds were also monitored in earthworms, vegetation, and soil from the same areas. DDE levels consistently higher in samples taken from the northern Niagara peninsula, an area that had been heavily sprayed with DDT until it was banned in Canada in 1986. The high levels of DDE and its metabolites may explain reductions in reproductive success among kestrels in that part of Ontario.