Southeast Brazil is a neotropical region composed of a mosaic of different tropical habitats and mountain chains, which allowed for the formation of bird-rich communities with distinct ecological niches. Although this region has the potential to harbor a remarkable variety of avian parasites, there is a lack of information about the diversity of malarial parasites. We used molecular approaches to characterize the lineage diversity of Plasmodium and Haemoproteus in bird communities from three different habitats in southeast Brazil based on the prevalence, richness and composition of lineages. We observed an overall prevalence of 35.3%, with a local prevalence ranging from 17.2% to 54.8%. Moreover, no significant association between prevalence and habitat type could be verified (p>0.05). We identified 89 Plasmodium and 22 Haemoproteus lineages, with 86% of them described for the first time here, including an unusual infection of a non-columbiform host by a Haemoproteus (Haemoproteus) parasite. The composition analyses of the parasite communities showed that the lineage composition from Brazilian savannah and tropical dry forest was similar, but it was different from the lineage composition of Atlantic rainforest, reflecting the greater likeness of the former habitats with respect to seasonality and forest density. No significant effects of habitat type on lineage richness were observed based on GLM analyses. We also found that sites whose samples had a greater diversity of bird species showed a greater diversity of parasite lineages, providing evidence that areas with high bird richness also have high parasite richness. Our findings point to the importance of the neotropical region (southeast Brazil) as a major reservoir of new haemosporidian lineages.
Habitat modification may change vertebrate and vector-borne disease distributions. However, natural forest regeneration through secondary succession may mitigate these effects. Here we tested the hypothesis that secondary succession influences the distribution of birds and their haemosporidian parasites (genera Plasmodium and Haemoproteus) in a seasonally dry tropical forest, a globally threatened ecosystem, in Brazil. Moreover, we assessed seasonal fluctuations in parasite prevalence and distribution. We sampled birds in four different successional stages at the peak and end of the rainy season, as well as in the middle and at the end of the dry season. A non-metric multidimensional scaling analysis revealed that bird communities in the pasture (i.e., highly modified) areas were different from those in the early, intermediate, and late successional areas (secondary forests). Among 461 individual birds, haemosporidian prevalence was higher in pasture areas than in the more advanced successional stages, but parasite communities were homogeneous across these areas. Parasite prevalence was higher in pasture-specialists birds (resilient species) than in forest-specialists species, suggesting that pasture-specialists may increase infection risk for co-occurring hosts. We found an increase in prevalence between the middle and end of the dry season, a period associated with the beginning of the breeding season (early spring) in southeastern Brazil. We also found effects of seasonality in the relative prevalence of specific parasite lineages. Our results show that natural forest recovery through secondary succession in SDTFs is associated with compositional differences in avian communities, and that advanced successional stages are associated with lower prevalence of avian haemosporidian parasites.
2014). Spatiotemporal variation in phyllostomid bat assemblages over a successional gradient in a tropical dry forest in southeastern Brazil . Abstract:The aim of this study was to investigate the spatiotemporal variation in richness, abundance, structure and composition of phyllostomid bats over a successional gradient in a tropical dry forest in south-eastern Brazil. Four successional stages (pasture, early, intermediate and late) were sampled in the northern part of the state of Minas Gerais. Bats were sampled using mist nets at three sites for each of the four successional stages (12 sites in total) during eight periods between 2007 and 2009. A total of 537 individuals were captured (29 recaptured), distributed among four families and 22 species. Bat abundance and richness varied in space, being higher in the late-successional stage, and over time, being significantly lower during the dry season. When compared between guilds, only the abundance of omnivores varied significantly during the sampled months. Our results demonstrate that areas of late-successional stages showed higher bat richness and abundance in comparison with areas undergoing secondary succession. Our results also suggest the use of early-successional areas as flying routes by bats can lead to failure to detect differences in bat composition within successional gradients. We suggest future studies should assimilate landscape-level analyses into their studies to better evaluate the effects of successional gradients on bat assemblages.
Reintroduced environments represent stressful conditions to plants that can be observed in different ways. We evaluated the relationships between fluctuating asymmetry (FA), herbivory, and plant ontogeny of Chamaecrista semaphora (Fabaceae) under natural and restored habitat conditions. The patterns of leaf FA and herbivory by folivorous insects (chewing) on saplings and mature plants in each habitat were determined. No relationship was found between FA and herbivory on the two ontogenetic stages in both environments, suggesting that FA did not represent an indicator of stress. The frequency and amount of leaf area removed by folivores were higher in saplings compared to adult plants under the natural habitat, while the opposite trend was observed on restored habitat for adult plants. The restored habitat did not represent an environmental stress condition to C. semaphora, indicating that this endemic plant may represent a good candidate to restoration programs in harsh environments. However, we observed great differences in leaf FA and herbivory among individuals within habitats. Knowledge on plant quality, competition, physiology, and interactions with natural enemies are highly needed to support long lasting programmes on restoration of harsh environments.
Studies on avian diet provide important information about biology and ecological relationships of species, for instance, predation and competition. Despite the importance, studies about trophic ecology in the Neotropical region are still scarce, especially in the Amazonian region. The Brazilian Amazon hosts a high diversity of birds, with about 1300 resident species. However, trophic ecology of the regional avifauna is still poorly studied. This paper aims to describe the composition of the diet of some Amazonian bird species. Bird specimens were collected in the Aripuanã municipality, northern Mato Grosso state, Brazil. The analysis of the stomach contents of the collected birds was the method used to assess diets of birds. We analysed the stomach contents of 59 birds of 40 species. A total of 573 food items were identified and could be assigned to 16 different classes. Hymenoptera was the most abundant class. Hymenoptera and Coleoptera classes were the most frequent. Our results provide information on the diet of endemic Amazonian species, of which there is a lack of information in the literature. These facts are therefore important for future studies on the biology and ecology of these birds.
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