Dinâmica das comunidades de aves no mosaico de hábitats do Pantanal do Rio Negro, MS
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2009-05-22
Autores
Rosa, Gustavo Adolfo Braga da [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
O Pantanal abriga formações florestais, savânicas, fluviais e lacustres em um mosaico de hábitats singularmente heterogêneo. Os objetivos deste trabalho foram avaliar a diversidade, a estrutura das comunidades e o uso de hábitats por aves no Pantanal do Rio Negro, MS (cap. I); e avaliar o uso de ambientes aquáticos (cap. II). I. Através de observações diretas amostramos quatro ambientes terrestres e três aquáticos. Registramos 279 espécies, com a maior riqueza no cerradão (189 espécies) e a menor riqueza nos campos (84 espécies). A diversidade beta (entre ambientes) contribuiu com 68% da diversidade regional. 22 % das espécies foram encontradas em seis ou todos os sete ambientes, destacando-se os nãopasseriformes, onívoros e aquáticos/limnícolas. As maiores abundâncias foram encontradas nas salinas e no rio. A correlação positiva entre abundância e distribuição espacial indicou que o hábito generalista em relação ao uso de hábitat deve contribuir para o incremento da abundância. A abundância de frugívoros foi maior no período seco, possivelmente devido a um aumento no deslocamento frente à maior escassez de frutos. II. No meio aquático amostramos 7.817 aves aquáticas, representando 58 espécies, das quais 32 são migratórias. A riqueza nos três ambientes foi muito similar (43 a 45 espécies). As salinas obtiveram a mais baixa equidade e a mais alta densidade. A similaridade na composição entre os ambientes foi maior entre baías e salinas e menor entre salinas e rio. As espécies mais abundantes foram Himantopus melanurus e Tringa flavipes nas salinas, Dendrocygna viduata e Jacana jacana nas baías, Phalacrocorax brasilianus e Megaceryle torquata no rio. Houve flutuação sazonal na avifauna, mais expressiva nas salinas, com abundância 100% maior na seca e riqueza de espécies 40% maior na cheia. Fatores como nível d’água, disponibilidade...
The Pantanal comprises several forest, savanic and aquatic formations in a peculiar mosaic of habitats. The aims of this study were to assess diversity, community structure and use of habitats by birds in the Pantanal of Rio Negro Region (chapter I); and assess the use of aquatic habitats by birds (chapter II). We surveyed four terrestrial and three aquatic habitats through direct observations. 279 bird species were found, with the highest species richness in the semidecidual forest (189 species) and the lowest (84 species) in the grasslands. Beta diversity (turnover of species) was responsible for 68% of the regional diversity. 22% of the species were found in six or in all seven habitats, with high proportion of non-passerines, omnivores and aquatic birds in this group. The highest abundances were found in salt lakes and in the river. A positive correlation between abundance and spatial distribution suggests that habitat flexibility in birds increases abundance. The abundance of frugivores was higher in the dry season, possibly as a consequence of fruit scarcity and increased movement of foraging birds. In the aquatic habitats we surveyed 7.817 aquatic birds, from 58 species, with 32 migrant species. Species richness was similar among fresh-water lakes, salt lakes and the river (43 to 45 species). Salt lakes showed highest density and lowest equitability. Similarity in species composition was highest between the lakes and lowest between salt lake and river. The most abundant species were Himantopus melanurus and Tringa flavipes in salt lakes, Dendrocygna viduata and Jacana jacana in fresh water lakes, Phalacrocorax brasilianus and Megaceryle torquata in the river. Seasonal changes in bird communities were prominent in salt lakes, with 100% higher abundance in dry season and 40% higher species richness in wet season. Water level, mudflats, riparian vegetation, and aquatic diversity... (Complete abstract click electronic access below)
The Pantanal comprises several forest, savanic and aquatic formations in a peculiar mosaic of habitats. The aims of this study were to assess diversity, community structure and use of habitats by birds in the Pantanal of Rio Negro Region (chapter I); and assess the use of aquatic habitats by birds (chapter II). We surveyed four terrestrial and three aquatic habitats through direct observations. 279 bird species were found, with the highest species richness in the semidecidual forest (189 species) and the lowest (84 species) in the grasslands. Beta diversity (turnover of species) was responsible for 68% of the regional diversity. 22% of the species were found in six or in all seven habitats, with high proportion of non-passerines, omnivores and aquatic birds in this group. The highest abundances were found in salt lakes and in the river. A positive correlation between abundance and spatial distribution suggests that habitat flexibility in birds increases abundance. The abundance of frugivores was higher in the dry season, possibly as a consequence of fruit scarcity and increased movement of foraging birds. In the aquatic habitats we surveyed 7.817 aquatic birds, from 58 species, with 32 migrant species. Species richness was similar among fresh-water lakes, salt lakes and the river (43 to 45 species). Salt lakes showed highest density and lowest equitability. Similarity in species composition was highest between the lakes and lowest between salt lake and river. The most abundant species were Himantopus melanurus and Tringa flavipes in salt lakes, Dendrocygna viduata and Jacana jacana in fresh water lakes, Phalacrocorax brasilianus and Megaceryle torquata in the river. Seasonal changes in bird communities were prominent in salt lakes, with 100% higher abundance in dry season and 40% higher species richness in wet season. Water level, mudflats, riparian vegetation, and aquatic diversity... (Complete abstract click electronic access below)
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Avifauna - Rio Negro, Zoologia, Biodiversidade, Biodiversity
Como citar
ROSA, Gustavo Adolfo Braga da. Dinâmica das comunidades de aves no mosaico de hábitats do Pantanal do Rio Negro, MS. 2009. 91 f. Tese (doutorado) - Universidade Estadual Paulista, Instituto de Biociências de Botucatu, 2009.