Taxocenose das aves da microbacia hidrográfica das nascentes do rio Ibicuí Mirim /RS

Abstract

This work was carried out in the micro basin of the headwaters of the Ibicuí Mirim river, until the Saturnino de Brito dam, and aimed to establish relationships between avifauna with different habitats in the area, using as tool the System of Geographic Information (SIG), with the purpose of evaluating the similarity of bird species in an environment with the same phytogeographic characteristics, its abundance and wealth. In this way thematic maps of land use were created and analysis performed on the physiognomy of micro basin giving support to make it possible to characterize it as the kind of environments, showing therefore that the area of 8695.20 hectares, is divided into four different habitats : area of fields (20.61% of the area), swamp area (3.72% of the area), forest area (18.25% of the area), and area of agriculture (57.42% of the area), characterizing an intense human action on the environment. The linear transects of them showed similar physiognomic characteristics in birds and found results after the total effort of 672 hours of collections, recording 4828 individuals belonging to 163 species (51 families). Of these, ten are migratory species and one is errant (Egretta caerulea), for the state of Rio Grande do Sul. The most representative order was Passeriformes with 19 families and 80 species. Among the families that represented a greater number of species was the Tyrannidae with nineteen species followed the families Emberizidae, with 12 species and Icteridae, with 8 species, all of the order Passeriformes. The largest number of individuals occurred in the following species: Zenaida auriculata, Patagioenas picazuro, Zonotrichia capensis and Vanellus chilensis. Ahead of the problems caused to the species of birds, the production model employed in the of microbasin, which provides a reduction in diversity and loss of natural potentialities, more deepened studies on issues related to the use and occupancy of land and conflict areas, like the monitoring of social, economic and environmental impacts of agricultural forestry and grazing activities should be made in order to assist the planning and organization of activities on farms, indicating the areas that should be preserved and not used for production purposes, making the operation the land economically viable, socially fair and environmentally correct.