Threatened grassland bird populations in the western Iberá Wetlands, Corrientes, Argentina

Grasslands environments in Argentina are highly transformed and poorly represented in protected areas. Particularly, northeastern grasslands contain 23 threatened bird species, which highlights the need to assess the status of their local populations. The objective of this study was to provide updated information on richness, abundance and density of threatened grassland bird species in the western Iberá wetlands (Corrientes, Argentina), at the Empresas Verdes Argentina S.A. property (28 ° 12’S, 57 ° 33’W). We recorded global and national threatened species with 136 point counts (10 minutes, 200m radius) in grasslands (predominance of grasses) and wetlands (predominance of marsh and acuatic plants) during the breeding season. Richness of threatened birds species was obtained from field work and bibliographical review, while mean richness, mean abundance and density were calculated based on systematized records. We recorded 249 individuals and a total richness of 18 threatened species including Endangered (e.g. Sporophila iberaensis), Vulnerable (e.g. Anthus nattereri) and Near Threatened species (e.g. Eleothreptus anomalus). Significant differences were found between pastures and wetlands in density (0.322 ind./ha vs.0.234 ind./ha, p0.0162) mean richness (1.43 ± 1.22 vs. 0.6 ± 0.54, p0.0002) and mean abundance (2.02 ± 1.98 vs. 1.47 ± 3.03,p 0.0162). Cairina moschata, Jabiru mycteria and Amblyramphus holoseriseus are more abundant in wetlands, and Alectrurus risora, Xolmis dominicanus, Sporophila spp (pileata, cinnammomea, hypochroma, hypoxantha, iberaensis) in grasslands. These results reinforce the conservation commitment in the western Iberá wetlands.