The effects of forest-savanna-grassland gradients on bird communities of Chiquitano Dry Forests domain, in western Brazil

Abstract

Different vegetation types are distributed in mountains according to altitude, topography and soil. The composition and structure of bird communities in these areas can change in relation to the vegetation gradient, with particular communities occupying each habitat type. In this study we present the changes in composition, species richness and bird abundance over the gradient of forests, savannas and altitudinal grasslands of Maciço do Urucum, a mountainous region located in the Chiquitano Dry Forests domain in western Brazil. We recorded 165 bird species through qualitative and quantitative methods. Forested savannas, riparian forests and submontane forests presented the highest richness and abundance of birds, while arboreal savannas and altitudinal grasslands had intermediate and low values, respectively. The bird composition was similar between riparian and submontane forests, while other vegetation types present more dissimilar bird communities. Our results show differences in composition, richness and bird abundance among the vegetation types present at Maciço do Urucum, and highlight an important function of vegetation gradients for the conservation of bird communities in mountains. Additionally, this is the first study of the bird communities in the Brazilian Chiquitano Dry Forests, an important domain in the west of Brazil which has been poorly studied.

Assessment of Avian Occurrence in the Brazilian Chaco

“…7,20,21 The birds of the Chaco exhibit very low avian endemism 7 and they present very close affinities with the surrounding avifauna. 10,[24][25][26][27] However, the region of Porto Murtinho presents species of birds which are particular to the Chaco, 23 with a close bio geographical connection with the nearby Cerrado and the Pantanal biomes. Considering the location of the Chaco and its limits to the west with the Andes, the Amazon in the north, and the Pampas and Patagonia in the south, there has been a high bio geographical interest in the region.…”

Estrutura De Comunidades De Aves De Áreas Úmidas Do Pantanal E Cerrado Sul Mato-Grossense

“…O estado de Mato Grosso do Sul está localizado no centro-oeste do Brasil, ocupando um território de 360.000 km 2 cobertos principalmente pelos domínios biogeográficos do Cerrado e Pantanal (IBGE 2012). Além disso, também são observados remanescentes de Mata Atlântica no sul e leste do estado (Godoi et al 2013), manchas de floresta seca, também conhecidas como Florestas Chiquitanas, no extremo noroeste, na divisa com a Bolívia (Godoi & Souza 2016), e de Chaco no extremo oeste, na divisa com o Paraguai (Straube et al 2006). Devido à grande extensão territorial e presença de diferentes domínios biogeográficos, o Mato Grosso do Sul apresenta alta riqueza de espécies de aves, com ao menos 630 espécies pertencentes a 26 ordens e 74 famílias (Nunes et al 2017), o que corresponde a aproximadamente 33% das 1919 espécies de aves do Brasil (Piacentini et al 2015).…”