Patrones de riqueza y diversidad de aves en áreas verdes del centro urbano de San Salvador, El Salvador

Increasing urbanization has led to natural ecosystems being constantly replaced by an urban landscape, a process that is very noticeable in El Salvador, due to its small territorial extension (21.041 km.) and high population density (291 hab/km.). We performed an inventory in 12 urban green areas, with different sizes, shape and distances from the largest forest area in the metropolitan zone, based on the McArthur and Wilson’s (1967) island biogeography theory. We evaluated if the richness, diversity and equitability of birds were related to the size and distance of the green areas and if their shape had any effect on the richness of birds. We observed a total of 20 bird species and we classified them according to their diet (generalist and specialist). We observed that the distance did not influence the bird richness and that there was no interaction between size and distance variables, but the size of the green area did influence. The richness of birds with specialist diet increased in the more circular green areas than in the irregular ones. We conclude that in the urban center of San Salvador, the presence of large and circular green areas contributes more to the specialist diet birds’ richness, than areas of similar size but of irregular shape. However, small areas contribute more to the specialist diet birds’ richness, if its shape is more circular.