Anais da Academia Brasileira de Ciências ISSN: 0001-3765 [email protected] Academia Brasileira de Ciências Brasil GODOI, MAURICIO N.; DE SOUZA, EDIVALDO O. The effects of forest-savanna-grassland gradients on bird communities of Chiquitano Dry Forests domain, in western Brazil Anais da Academia Brasileira de Ciências, vol. 88, núm. 3, 2016, pp. 1755-1767 Academia Brasileira de Ciências Rio de Janeiro, Brasil Available in: http://www.redalyc.org/articulo.oa?id=32748476014 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Anais da Academia Brasileira de Ciências (2016) 88(3 Suppl.): 1755-1767 (Annals of the Brazilian Academy of Sciences) Printed version ISSN 0001-3765 / Online version ISSN 1678-2690 http://dx.doi.org/10.1590/0001-3765201620150615 www.scielo.br/aabc The effects of forest-savanna-grassland gradients on bird communities of Chiquitano Dry Forests domain, in western Brazil MAURICIO N. GODOI1 and EDIVALDO O. DE SOUZA2 1Programa de Pós-Graduação em Ecologia e Conservação, Centro de Ciências Biológicas e da Saúde, Universidade Federal de Mato Grosso do Sul, Cidade Universitária, s/n, 79070-900 Campo Grande, MS, Brasil 2Departamento de Biologia, Universidade Federal de Mato Grosso do Sul/UFMS, Campus Universitário de Aquidauana, CPAQ, Avenida Oscar Trindade de Barros, 740, Unidade II, Serraria, 79200-000 Aquidauana, MS, Brasil Manuscript received on August 27, 2015; accepted for publication on December 7, 2015 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. Key words: altitudinal grasslands, avian communities, Chiquitano Dry Forests, habitat diversity, habitat use, mountains. INTRODUCTION abundant in specific vegetation types, while other species have wide distributions with in gradients. In landscapes formed by vegetation gradients, bird Therefore, in areas with vegetation gradients it is community composition can be affected by the presence and distribution of different vegetation possible to distinguish different bird communities types (Skowno and Bond 2003, Jankowski et al. associated with each vegetation type (Tubelis and 2012). This pattern is due to the fact that many Cavalcanti 2001, Piratelli and Blake 2006, Posso et bird species are exclusive to certain habitats or are al. 2013, Godoi et al. 2016). Correspondence to: Mauricio Neves Godoi In mountain habitats, vegetation types E-mail: [email protected] are usually distributed in relation to altitude, An Acad Bras Cienc (2016) 88 (3 Suppl.) 1756 MAURICIO N. GODOI and EDIVALDO O. DE SOUZA topography and soil (Navarro 1992, Blake and of birds in a vegetation gradient in the Maciço Loiselle 2000). In these regions, the diversity and do Urucum and (2) describe the dissimilarities composition of bird communities could present in bird composition between different vegetation spatial variations in relation to the presence and types which occur in the landscape of Maciço do distribution of different vegetation types (Navarro Urucum. 1992, Blake and Loiselle 2000, Melo-Júnior et al. 2001, Mallet-Rodrigues et al. 2010). MATERIALS AND METHODS In western Brazil there are mountains which Study Area present extensive gradients of natural vegetation formed by forests, savannas and natural grasslands, The Maciço do Urucum is a mountainous region such as the Serra da Bodoquena, Serra de Maracaju located in the Chiquitano Dry Forests domain in the and Maciço do Urucum. In the Serra da Bodoquena extreme west of Brazil (Olson et al. 2001), near the and Serra de Maracaju inventories of bird species border of Bolivia, in the county of Corumbá, Mato showed high species richness, which could be Grosso do Sul state (Figure 1). This region occupies 2 partially explained by habitat diversity in these an area of 1300 km with mountains delimited by regions (Pivatto et al. 2006, Nunes et al. 2013). the Paraguai river to the north and flooded areas of In the Maciço do Urucum there is a marked Pantanal to the south and east. The climate of the gradient of forests, savannas and altitudinal region is Awa, according Koeppen´s classification, grasslands (Cáceres et al. 2011), but no basic with distinct periods of rainy (October-March) and studies on bird communities exist, with no data dry (April to September) seasons, with average on bird species distributions among the different annual rainfall of 1070 mm (Pott et al. 2000, Tomas vegetation types. However, these data are essential et al. 2010). in understanding how vegetation gradients affect The elevation of the mountains varies from the local composition and structure of bird 150 to 1130 m above sea level, and the natural communities and to bird conservation in Maciço vegetation gradient is formed by decidual and do Urucum. semidecidual seasonal forests, riparian forests, Furthermore, the Maciço do Urucum is located forested savannas (cerradão), arboreal savannas in the Chiquitano Dry Forests domain, which (cerrado stricto sensu) and altitudinal grasslands occurs in eastern Bolivia and in a very restricted (campos de altitude) (Pott et al. 2000, Tomas et al. area in western Brazil (Vasconcelos and Hoffmann 2010). The plant communities are diverse and suffer 2006). Although some studies on bird communities biogeographic influences from different domains, have been conducted in the Chiquitano Forests of like the Chiquitano Forests, Cerrado, Chaco, Bolivia (Davies 1993, Parker 1993, Remsen and Atlantic Forests and Amazonian Forests (Pott et Parker 1993, Flores et al. 2001, 2002, Brooks et al. 2000, 2011, Salis et al. 2004). This region also al. 2005), there are no studies focusing on bird contains anthropogenic landscapes, like pastures communities in the brazilian Chiquitano Forests. for cattle ranching and areas used for mining of This study is the first to describe the iron, aluminum and limestone, which are the main composition, richness and abundance of bird economic activities in the region. communities along vegetation gradients in Methods Chiquitano Dry Forests of Brazil. Specifically, the objectives of this study were to: (1) present We sample bird communities in 40 stations, using the species richness, abundances and composition eight stations from each of the following vegetation An Acad Bras Cienc (2016) 88 (3 Suppl.) BIRDS OF THE BRAZILIAN CHIQUITANO FORESTS 1757 Figure 1 - The Maciço do Urucum (star) in western Brazil, and ecoregion according to Olson et al. (2001). types: riparian forests, seasonal submontane forests, most bird species were active. At each station we forested savannas (cerradão), arboreal savannas sampled eight times (80 minutes of sampling eff ort) (cerrado stricto sensu) and altitudinal grasslands between July 2012 and October 2014, except for (campos de altitude) (Table I). four stations in the altitudinal grasslands, which At each station we placed a point count with a we sampled only twice (20 minutes of sampling fi xed radius of 50 m and 200 m of minimal distance eff ort), in July and October 2012 (Table I). In order from any other point, except for the points located to more precisely characterize the bird community in altitudinal grasslands, where we separated composition we also recorded bird species that we points by 150 m due to the restricted available observed in the intervals between each point count. area. Each point count was sampled for 10 minutes Data AnaLysIs consecutively, in which the number and species of all birds were recorded through visual or auditory For each station we recorded composition, richness observations (Anjos et al. 2010, Vielliard et al. and abundance (number of contacts) per species. 2010). The species abundance was expressed by Punctual Samplings were always performed in the early Abundance Index (PAI), which is a ratio between morning, between 06:00 and 09:00 hours, when the total number of specie´s contacts by total An Acad Bras Cienc (2016) 88 (3 Suppl.) 1758 MAURICIO N. GODOI and EDIVALDO O. DE SOUZA TABLE I Stations used for sampling bird communities along the vegetation gradient in Maciço do Urucum, western