Research, management, and status of the osprey in North America

Abstract

Osprey populations were studied throughout North America during the last decade as a result of dramatic declines reported along the North Atlantic Coast in the1950s and early 1960s. Researchers used banding, localized studies, aerial surveys, and pesticide analyses to identify factors influencing regional populations. Declining populations showed extremely poor production, contamination by environmental pollutants (including DDT and its metabolites, dieldrin, and polychlorinated biphenyls) and thin-shelled eggs. Following the reduced use and eventual ban of DDT and dieldrin, productivity began to improve. Improvement in affected populations, mainly those along the Atlantic Coast and in the Great Lakes region, began in the late 1960s and is continuing in the 1970s. Most populations in the South Atlantic region, in Western North America, and in Florida and the Gulf of California appeared to be producing at normal or near-normal rates in the late 1960s and early 1970s. Although some of the most severely affected populations are still not producing at normal rates, the pattern of improvement and an increase in management activities, including provision of nesting platforms and establishment of Osprey management zones, allow cautious optimism about the future of the species in North America. With its low recruitment potential, however, recovery will be slow.