CONICET | Buscador de Institutos y Recursos Humanos

The migratory subspecies of the ??American?? Osprey (Pandion haliaetus carolinensis) breeds across most of North America. Most of these Ospreys winter north of the equator, although significant numbers travel farther south, reaching Argentina. The number of Osprey sightings in Argentina has increased since the first review of their status in this country. We analyzed records of Osprey migration and distribution in Argentina from 1993 to 2008. We found that Ospreys occur year-round in Argentina, with a higher concentration in spring to summer (1 October to 31 March). Our data confirmed that in northern and northeastern Argentina, Ospreys use river systems and their major tributaries, and in central and northwestern regions, they commonly frequent reservoirs. The apparent increase in the number of Osprey records in Argentina in the last decades may result from an actual population increase but may also reflect a larger number of observers. Recent records suggest that Osprey should be considered a regular visitor to northern Argentina. We confirm the importance of northeastern rivers, and central and north- western reservoirs as wintering areas. Argentina has been noted as an important wintering area for many migratory birds, but has been underestimated as a wintering area for Osprey.