LANDBIRD ASSEMBLAGES IN DIFFERENT AGRICULTURAL LANDSCAPES: A CASE STUDY IN THE PAMPAS OF CENTRAL ARGENTINA J

CODESIDO, MARIANO; GONZÁLEZ-FISCHER, CARLOS M; BILENCA, DAVID N.

THE CONDOR

COOPER ORNITHOLOGICAL SOC

Año: 2013 p. 8 - 16

0010-5422

The combination of countryside elements (e.g., crops and pasture lands, strip roadside vegetation, woodlots, temporary wetlands) increases landscape heterogeneity and defines different types of agricultural landscapes, from homogeneous landscapes dominated by a single countryside element (i.e., pure cropland or pure pastoral farming) to heterogeneous landscapes dominated by two or more countryside elements (i.e., mixed farming landscape). In this study we characterized landbird assemblages in different agricultural landscapes (cropland, pastoral and mixed landscapes) in the Pampas of central Argentina. We surveyed landbirds along transects to determine species richness, composition and abundance. Mixed landscapes had greater heterogeneity than pastoral and cropland landscapes. Mixed landscapes showed greater species richness than pastoral and cropland landscapes, particularly generalist species richness. On the other hand, cropland landscapes had lower grassland specialists richness (species of increased conservation concern in the Pampas) than pastoral and mixed landscapes. An indicator-species analysis supported the association of some grassland-specialists (Rhea americana, Asthenes hudsoni, Embernagra platensis, Pseudoleistes virescens) with pastoral landscapes. Our results suggest that maintaining landscape heterogeneity throughout the Pampas (i.e., mixed landscapes) is important for preserving bird species richness. However, it should point out that several threatened grassland specialists inhabiting the Pampas like Rhea Americana and Asthenes hudsoni are exclusively found at pastoral landscapes, so the long-term survival of these species will depend on the conservation of this landscape type.