versión On-line ISSN 1850-4884
The Pampean Region of Argentina has been gradually and completely transformed by agriculture (croplands and pastoral farming) and urbanization. Currently, there is a N-S gradient from a pure cropland through mix-farming to a pure pastoral landscape. We examine the response of raptorial birds to agricultural intensity by surveying birds and land use along 17 transects covering the gradient. To examine the relationship between species presence or abundance and agricultural intensity we used logistic and simple regressions and correlograms. We used Mantel Test and Redundancy Analysis to explore relationships between bird abundance and landscape elements. We recorded a total of 11 raptor species. Abundance of the raptor assemblage responded to the spatial structure of land use in the region, being more abundant in pastoral farming landscapes. Nonetheless, most species were found in both croplands and pastoral landscapes. From a regional perspective, the use of the land for crops seems to be more detrimental to raptors than pastoral farming, even though most raptor species showed to be tolerant to land use. However, within each particular landscape (cropland or pastoral land), the studied raptor species showed differences in the type of habitat they exploit.
Palabras clave : Abundance; Agriculture; Argentina; Land use; Pampean Region; Pastoral farming; Raptorial birds.