Aves associadas a fragmentos de mata na região central do PAMPA

Abstract

Although composed predominantly by grasslands, the Pampas Biome is impacted by the fragmentation of its forestry patches, and it is known that the presence of birds are negatively affected by this process. However, there are no studies regarding this for the Pampas Biome. In the face of this, our study aims to evaluate the effects of the fragmentation process in the presence of birds in forest patches, in the Brazilian Pampas. The study was carried out in the central region of Brazilian Pampas (Caçapava do Sul), in a formation known as Serra do Sudeste. In 2020 and 2021 we conduct 10 bird surveys, five in cold season and five in warm season, in seven forest fragments, through active search limited by time. We recorded 71 species, belonging to 10 orders and 26 families. Larger fragments showed highest richness. Only seven species were recorded in all fragments. With exception of the smallest fragment, all others showed unique species. By the use of Tukey analyses we found significant differences in the use of birds only for the smallest fragment in comparison with the four largest ones. We did not find statistical difference in the bird richness between warm and cold seasons, although the additional record of seven summer migrants. The ecological indexes showed that the diversity was positively related to the size of the fragment. Many understory species, with different diet specialization (omnivores, granivores, insectivores), showed good adaptation to fragmented landscape, probably because they take some advantage of the edge effect. Typical forestry species were also recorded, but with low frequencies, probably associated to small populations. Despite the size of the fragment, another important feature in the composition of the bird community was the isolation of the fragments. In our study we found only 26 species in common between the most distant fragments. An important record was the sight of Red-spectacled Parrot (Amazona petrei), included as Vulnerable in the Red List of IUCN. Our results show the importance of the forest patches and the environmental heterogeneity for biodiversity conservation. There are many threats for birds, especially in fragmented landscapes, that claim for attention in order to preserve this important microhabitat of the least protected and smallest Brazilian Biome.