Spatial Variation in Bird Community Composition in Relation to Topographic Gradient and Forest Heterogeneity in a Central Amazonian Rainforest

Luciano N. Naka,Renato Cintra

doi:10.1155/2012/435671

Abstract

We investigated the effects of landscape features and forest structure on the avian community at the Reserva Florestal Adolpho Ducke near Manaus, in the Brazilian Amazon. We sampled the landscape and forest in 72 50 × 50 m plots systematically distributed in the reserve, covering an area of 6,400 ha. The avifauna was sampled using mist nets and acoustic surveys near the plots. We found no significant relationships between landscape features and forest components in the plots and the number of bird species and individuals sampled. Results of Principal Coordinate Analyses, however, showed that bird species composition changes along a topographic gradient (plateau-slope-valley), and also in relation to leaf litter depth and distance to forest streams. We also found compositional differences in the avian community on the eastern and western water basins that compose the reserve. Our results suggest that although most bird species occur throughout the reserve, many species track differences in the landscape and the forest structure.

Highlights

Understanding how the structure of the habitat influences avian populations and communities is a key factor to link habitat and niche selection with species diversity [1, 2]
We recorded a total of 191 bird species during our study, more than 50% of all species ever recorded in the RFAD
We found significant differences in the composition of bird species based on qualitative mistnet data between the two basins

Summary

Introduction

Understanding how the structure of the habitat influences avian populations and communities is a key factor to link habitat and niche selection with species diversity [1, 2]. Several studies have focused on the factors affecting avian species richness and abundance in tropical forests, investigating the relationship between vegetation structure and bird communities [2, 8,9,10], but few have investigated how natural variations in the structure of the forest may affect entire species assemblages (but see [4, 7, 11]) When available, such studies are often done at small spatial scales [9, 12, 13], and the effects of habitat structure are rarely considered. In recent years a great body of knowledge has been gathered on general aspects of the biology and behaviour of many tropical species [19], little is known about the function of species in the ecosystem, and how a significant part of the bird community responds to the local variation observed in the structure of the forest

Methods

Results

Conclusion