Searching for food in a concrete jungle: feeding ecology of a Psittacine assemblage (Aves, Psittacidae) in a major Amazonian city.

The efficient use of food resources is a precondition for wild species´ survival in urban environments. The feeding ecology of animals in tropical cities, however, remains poorly investigated. Here we study the feeding ecology of parrots in Manaus, a major Amazonian city, and compare the results with a parrot assemblage living in undisturbed habitats. We recorded 203 feeding bouts from eight parrot species, which consumed parts of 51 plant species. Parrot diets were dominated by native palm species (Arecaceae). Exotic plants, however, constituted an important portion of the diet of some parrots. Levin's indices, a measure of food niche width, varied from 0.40 to 0.83, indicating an overall tendency to generalist diets. Diet overlap between species was small, indicating broad resource partitioning between members of the assemblage. The diversity of plants consumed in the natural environment was greater than in the urban environment (71 species vs. 52). However, the diversity of plants consumed was similar for parrot species recorded both in natural and urban environments, indicating that occupation of the city does not imply an impoverishment in parrot diets. Creation of municipal protected areas and increasing the city afforestation would provide complementary strategies for Manaus parrot conservation.

Avian Communities in the Amazonian Cangas Vegetation: Biogeographic Affinities, Components of Beta-Diversity and Conservation.

The Amazonian cangas is a vegetation type distributed as patches of open vegetation embedded in a matrix of tropical forest and that grows over iron-rich soils in the Serra dos Carajás region. To characterize cangas avifauna, we surveyed birds in eight patches varying from 43 to 1,366 hectares. Cangas avifauna has compositional affinities with savannas widespread throughout the Amazon and other biomes, and we estimate that more than 200 bird species occurs in this habitat. Species composition was relatively homogeneous, and the similarity among cangas patches was the dominant component of the beta-diversity. Bird communities in cangas patches exhibited statistically significant nested structure in respect to species richness and patch size. In contrast, the nested site arrangement was not affected by the isolation of patches. Number of species and composition are moderately affected by the area of cangas patches but not by its degree of isolation. To conserve this unique habitat are necessary a strict protection of carefully chosen patches of cangas and an investigation of the conservation value of secondary vegetation recovered by the mining companies.

Avian Communities in the Amazonian Cangas Vegetation: Biogeographic Affinities, Components of Beta-Diversity and Conservation

ABSTRACT The Amazonian cangas is a vegetation type distributed as patches of open vegetation embedded in a matrix of tropical forest and that grows over iron-rich soils in the Serra dos Carajás region. To characterize cangas avifauna, we surveyed birds in eight patches varying from 43 to 1,366 hectares. Cangas avifauna has compositional affinities with savannas widespread throughout the Amazon and other biomes, and we estimate that more than 200 bird species occurs in this habitat. Species composition was relatively homogeneous, and the similarity among cangas patches was the dominant component of the beta-diversity. Bird communities in cangas patches exhibited statistically significant nested structure in respect to species richness and patch size. In contrast, the nested site arrangement was not affected by the isolation of patches. Number of species and composition are moderately affected by the area of cangas patches but not by its degree of isolation. To conserve this unique habitat are necessary a strict protection of carefully chosen patches of cangas and an investigation of the conservation value of secondary vegetation recovered by the mining companies.