Quantitative studies on birds in urban areas of Buenos Aires with dense human population

Abstract

This paper deals with the distribution of birds in the city of Buenos Aires. Sixteen public squares and parks situated in different parts of the city were studied during the breeding season in 1979. The results of the bird census work are given in the following different manners: Asp = abundance of each species watched in each place (generally middle of five observations), with indication of minimum and maximum; Asp/ha; An = the abundance of all species in every place (population density); and D = dominance of each species in each place. The European species introduced in Argentina, Passer domesticus and Columba livia, dominate considerably in the majority of places, reaching up to 98%, particularly in some central public squares. Autochthonous species populations were generally observed to be notably less numerous, but in larger parks were found in relatively greater quantities, as is the case of Parque Saavedra with a dominance of 60%. The following autochthonous species were observed: Zenaida auriculata, Columbina picui, Furnarius rufus, Pitangus sulphuratus, Machetornis rixosa, Progne chalybea, Troglodytes aedon, Mimus saturninus, Turdus rufiventris, Molothrus bonariensis, Thraupis sayaca, Carduelis magellanica, Sicalis flaveola, and Junco capensis. The first results of the Ornithological Urban Program of the Estación de Hidrobiología Delta are given in the present paper