Bird communities present at a suburban residential area and in an exurban area in the Tafi Viejo Department (Tucumán, Argentina)

Abstract

Urban development threatens biodiversity, generating a gradient of environmental conditions from large cities to rural areas. This paper analyzes the differences in the composition of two bird communities during the dry period of the year, in a suburban residential area (SU) and exurban area (SPU). Similarity at the family and species level, and dominance of species, considering relative abundance and relative frequency of occurrence, diversity and evenness are evaluated. Rank-abundance curves and the relative importance index (IR) are reported. Seventy-nine species (36 shared) and 30 families were detected between the two sites. The similarity level was 75 % for families and 62.60 % for species. The dominant species were in SPU Zonotrichia capensis, Poospiza melanoleuca and Polioptila dumicola and in SU Z. capensis and Thraupis sayaca. The diversity and evenness indices were higher in SU, with a magnitude of change of 31.6 %. The distri- bution of the abundance in both communities was logarithmic. A greater number of species of high relative importance was recorded in SU. The more urbanized site showed greater richness, average number of individuals and average species per census and greater diversity than the site in the process of urbanization. Replacement of native species by locally invasive generalist species was observed.