Abstract

JURI, María D  and  CHANI, José M. Seasonal variation in the composition of bird communities in an urban gradient. Ecol. austral [online]. 2009, vol.19, n.3, pp.175-184. ISSN 1667-782X.

Urbanization affects the birds of a region in a complex way. Several studies from the Northern Hemisphere show a particular negative incidence on migratory species. In an urban area of the province of Tucuman, a previous work found that bird richness increased with plant cover in residential areas. However, it is not known their seasonal pattern and to what extent the degree of urbanization differentially affect resident species and the visitors. Here we analyzed the seasonal variation of birds' community and evaluate the impact of urbanization on resident species and visitors in an urban gradient over a period of two years. Birds diversity varied seasonally in the three locations: in the most urbanized site peaked in spring while in sites with minor and intermediate development was higher in winter and autumn. In those urban areas with the highest volume of vegetation, the species richness increased in general and the proportion of visitors in particular. Our data suggest that a greater area of gardens and trees of cities would allow the arrival of more visitors, whether migratory or resident of the natural environments that use the city as a refuge.

Keywords : Urbanization; Bird migration; Altitudinal displacement; Yungas; Premontane forest; Tucumán.

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