in the mid-1990's, the swainson's hawk (buteo swainsoni) turned into one of the most paradigmatic cases in relation to the potential effects of agricultural practices on wildlife in the argentine pampas. its habits of spatial segregation, prey and habitat selection, added to environmental conditions that determined demographic outbreaks of insect populations, most of them very prejudicial for crops and pastures implanted in this region, were factors that combined to result in a series of poisoning incidents that affected approximately to 20000 hawks, a 5% of the world population estimated in that moment. despite the fact that the pesticide that caused these mortality incidents has been banned from argentina and new mortality incidents have not been reported in the area, several important aspects of the wintering ecology of the swainson's hawk related with conservation planning are still unknown. in this paper we review the information available on the austral ecology of the swainson's hawk, analyzing those conservation measures taken to avoid the occurrence of new mortality incidents and the achievement of extension, educational and research goals. the swainson's hawk has become a "umbrella species" for the conservation of biodiversity in the agroecosystems of argentina and all the efforts made to preserve wintering populations of this raptor surely have resulted in the conservation of other birds inhabiting these habitats.
