A bird assemblage in a premontane subtropical forest relict: Percy Hill Park (Yerba Buena, Tucumán, Argentina)

Abstract

The composition, structure and temporal variation of a bird assemblage were studied in Percy Hill Park during the wet and dry seasons of 2007 and 2008. The Park is a remnant of premontane subtropical forest, located in Yerba Buena city, Tucumán, Argentina. Eleven point counts were selected and 62 censuses lasting 20 minutes each were carried out. For the analysis, the relative importance index (IR), frequency (F %) and the individual proportion of each species (pi) were used. Forty-eight species were identified including residents and visitors, only a few of which, generalists and adapted to urbanizations, were common and abundant in the assemblage. In the analysis of temporal variation, few differences were recorded in the composition and abundance during the dry season in which visitor species, most of them altitudinal migrants, resulted more common than visitors during the rainy season. Compared to studies carried out in the Park seven years earlier, the present study showed a decrease in species richness and changes in the temporary variation of the assemblage, possibly related to the growth in urbanization and loss of vegetation. Conservation of the Park is therefore very important as a natural refuge within an urbanized matrix for resident and migratory species and as a relict of premontane subtropical forest.