Distribution, composition and seasonality of aquatic birds in the Nhecolândia sub-region of South Pantanal, Brazil

Abstract

Despite remarkable significance of Pantanal for the conservation of aquatic birds, the status of their populations, the spatiotemporal patterns of distribution and habitat use and structure of communities are little known. Thus, we studied three aquatic environments (Negro river, bays and salines) from 2007 to 2009 in the Nhecolândia Pantanal to verify the distribution and composition of aquatic birds and also if there is significant seasonal influence on these aspects. We adopted the transect method (288 hours of sampling) and recorded 135 species (7.834 individuals). The Negro river showed the highest diversity, while the salines the lowest. The similarity of aquatic bird communities was higher between bays and salines, followed by Negro river and bays and lower between salines and Negro river. The equidistribution is more variable in the salines and more stable in the Negro river. The environments strongly differ from each other in aquatic bird composition in space (habitat use and distribution) and time (seasonal water fluctuations). The diversity of bird community in the dry season varies significantly in the salines, followed by the bays and more stable in the Negro river. The Negro river, regardless of large annual amplitude of flow, is more seasonally stable since its riparian vegetation is continuous (not isolated) and constant. These aspects provide better conditions to stay all year, contributing to decrease the seasonal nomadic tendencies of aquatic birds. Finally, all these data provide strong arguments to the preservation of all phytophysiognomies in the Nhecolândia sub-region of Pantanal, but with special attention to the salines widely used by many flocks of aquatic birds (mainly in the dry season) and migrant and/or rare species restricted to this habitat. Isto se deve principalmente pela mata ciliar no rio Negro ser contínua (não isolada) e constante ao longo do ano. Estes aspectos proporcionam melhores condições para as aves se manterem durante todo o ano neste ambiente, contribuindo para diminuir as tendências sazonais nômades de aves aquáticas. Todos estes dados fornecem fortes argumentos para o preservação de todos as fitofisionomias na sub-região da Nhecolândia, mas com especial a atenção para as salinas amplamente utilizadas por muitos bandos de aves aquáticas (principalmente no período seco) e migrantes e/ou espécies raras restritas a este habitat. KeywordsPalavras-chave: heterogeneidade, conservação, dinâmica, aves aquáticas, Pantanal.

Temporal and spatial variation of richness and abundance of the community of birds in the Pantanal wetlands of Nhecolândia (Mato Grosso do Sul, Brazil)

“…its riparian vegetation is continuous (not isolated) and constant (Donatelli et al, 2014). Our results showed the same pattern recorded by these authors in relation to aquatic habitats but this work, the first of its kind, will be a reference for further studies of birds in Pantanal, for various fields of research.…”

“…In terms of aquatic habitats, the diversity of bird community in the dry season varies significantly in the salines, followed by the bays and more stable in the Negro river. The Negro river, regardless of large annual amplitude of flow, is more seasonally stable since its riparian vegetation is continuous (not isolated) and constant (Donatelli et al, 2014). Our results showed the same pattern recorded by these authors in relation to aquatic habitats but this work, the first of its kind, will be a reference for further studies of birds in Pantanal, for various fields of research.…”

“…Naumburg (1930), Mitchel (1957), Brown (1986), Cintra and Yamashita (1990), Dubs (1992), Tubelis and Tomas (2003), Tomas (2004a and2004b), Nunes, Tizianel & Tomas (2006), Nunes, Silva & Tomas (2008), Figueira, Cintra, Viana & Yamashita (2006) and Donatelli, Posso & Toledo (2014) are among the researchers who investigated the richness of the birds in several regions of Pantanal. Nevertheless, an analysis of the diversity and dynamics of bird species in the Pantanal region is still lacking.…”

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

“…A alta produtividade dá suporte para uma imensa biomassa de plantas aquáticas, invertebrados e vertebrados (especialmente peixes), que compõe a base da cadeia alimentar das áreas úmidas pantaneiras, possibilitando a manutenção de grandes populações de diferentes espécies de aves (Harris et al 2005). Desta forma, no Pantanal podem ser observados, com muito mais frequência que no Cerrado, sítios de alimentação, dormitórios e colônias reprodutivas contendo centenas ou mesmo milhares de aves de áreas úmidas (Sick 1997, Figueira et al 2006, Oliveira 2006, Rosa 2009, Figueira et al 2011, Donatelli et al 2014.…”

“…Apesar de todas estas ameaças, a estrutura das comunidades de aves de áreas úmidas do Pantanal e Cerrado ainda são pouco estudadas (Figueira et al 2006, Oliveira 2006, Rosa 2009, Figueira et al 2011, Donatelli et al 2014, e aspectos relevantes destas comunidades são pouco conhecidos, como a riqueza, abundância, e especialmente as possíveis variações na composição de espécies entre estes dois importantes domínios biogeográficos. Desta forma, neste estudo são apresentadas informações sobre a composição, riqueza de espécies e abundância de aves de ambientes úmidos do Pantanal e Cerrado do estado de Mato Grosso do Sul.…”