Search

Chiggers are larval ectoparasites of the Trombiculidae that can transmit pathogens to their hosts. In this study, chiggers collected from birds in Brazil were morphologically identified as Blankaartia sinnamaryi, Eutrombicula batatas, Eutrombicula daemoni, Eutrombicula goeldii, Eutrombicula tinami, and Parasecia gilbertoi. For these specimens, a beginning attempt at molecular identification were also provided, as well as, were genetically screened to detect bacterial pathogens. The species B. sinnamaryi and E. tinami were positive for Rickettsia felis-like and 'Candidatus Rickettsia colombianensi'-like, respectively. For the other agents (Anaplasmataceae, Borrelia spp. and Orientia tsutsugamushi), the tests were negative. This is the first report of 'Ca. R. colombianensi'-like and the second record of R. felis-like in chigger collected on birds from Brazil.

Urbanization is a worldwide problem affecting wildlife negatively. Cities cause habitat suppression, fragmentation, among other disease spreading, suitable conditions for exotic species, and direct animal kills—consequently, local native species might be extinct. Still, urban areas can also provide biodiversity maintenance because some species can be adapted to the urban environment. Here, we assess how the urban environment influences the displacement of native turquoise-fronted Amazon (Amazona aestiva). We created a map of environmental suitability to modeling A. aestiva displacement routes among three protected areas in Brasilia, Brazil. We tested (1) if the modeled corridors tend to be near to the areas where A. aestiva occurs and (2) how landscape spatial heterogeneity influences those modeled routes. We expected to observe oriented routes in homogeneous areas (few pixels with high-frequency selection), and the opposite in heterogeneous areas. To test our hypotheses, we recorded A. aestiva and correlated its presence/absence with the modeled corridors and correlated the landscape spatial heterogeneity with different metrics of the modeled corridors. Our results indicate that at least one of the modeled routes was near to the points with parrots. In general, potential dispersal routes with little spatial variation occurred in homogeneous areas. In the urban matrix, potential routes were less oriented with more spatial variation. Our results suggest the adoption of different strategies to manage the natural environment in an urban matrix. By managing the spatial heterogeneity, it is possible to direct how the species use the space, promoting the displacement to desired areas, avoiding the more urbanized ones.

The use and partition of the acoustic space by anuran species is of special interest for evaluating inter-specific interactions in acoustic traits. Here we evaluate the acoustic space partitioning by four species of hylidae over the course of eleven months, at the Ecological Station of Águas Emendadas - DF, central Brazil. The acoustic niche overlap among species was smaller than expected by chance, indicating a competition in the use of this resource. If competition affects the use of acoustic resouces by species, low overlap on advertisement call traits are relevant in open habitats anuran assemblies.

Spatial patterns of stable isotopes in animal tissues or “isoscapes” can be used to investigate animal origins in a range of ecological and forensic investigations. Here, we developed a feather hydrogen isotope (δ2Hf) isoscape for Brazil based on 192 samples of feathers from the family Thraupidae from scientific collections. Raw values of δ2Hf ranged from -107.3 to +5.0‰, with higher values at the Caatinga biome (northeast Brazil) and lower values at the Amazon and Pantanal. A Random Forest (RF) method was used to model the spatial surface, using a range of environmental data as auxiliary variables. The RF model indicated a negative relationship between δ2Hf and Mean Annual Precipitation, Precipitation in the Warmest Quarter, and Annual Temperature Range and positive relationships for amount-weighted February-April precipitation δ2H (δ2Hp(Feb-April)) and Mean Annual Solar Radiation. Modelled δ2Hf values ranged from -85.7 to -13.6‰. Ours is the first δ2Hf isoscape for Brazil that can greatly assist our understanding of both ecological and biogeochemical processes controlling spatial variation in δ2H for this region. This isoscape can be used with caution, due to its poor predictive power (as found in other tropical regions) and can benefit from new sample input, new GNIP data, ecological and physiological studies, and keratin standard material better encompassing the range in feather samples from Brazil. So, we encourage new attempts to build more precise feather H isoscapes, as well as isoscapes based on other elements.

Birds living near airports can reduce the noise interference by advancing their dawn chorus timing and avoiding the start of airport operations. Data supporting this finding come from temperate areas, but little is known from tropical environments, where seasonal variation is lower and biodiversity is higher. Here, we investigated whether 15 tropical bird species are able to advance their dawn song and avoid aircraft noise interference. We sampled dawn song in three airports and three control sites in Brazil, using automated recording units. We found that dawn song times were not globally affected by the exposure to airport noise. Instead, changes were highly variable and species-specific, as dawn song onset was significantly advanced in two and delayed in four species. This large variation in responses was surprising given patterns found in previous studies. Indeed, this is the first time that a significant delay is reported for bird’s dawn song. We explored whether between-species differences in this response could be explained by additional variables (song frequency, degree of urbanity, and noise release), but none of them explained the direction or the strength of the changes. We suggest that earlier airport activity and shorter variations in day length and in twilight duration of tropical areas may be restricting birds’ ability to change dawn song timing. Further studies should consider these differences and analyze to what extent populational declines in noisy areas and the resultant reduced competition for acoustic space may be affecting the changes in dawn chorus onset time. Significance statement: Birds have been shown to advance the timing of their song at dawn to avoid airport noise in Europe. However, we did not find a similar pattern in the birds near three Brazilian airport-affected sites, where the tropical environment can be a key factor (higher biodiversity and lower seasonal variation). We found that of the 15 studied species, only two followed this pattern, 9 species showed no changes in their timing, and 4 species showed the opposite trend, delaying their dawn song in an apparently non-adaptive manner. Neither differences in the birds’ song frequencies and degree of urbanity nor the noise release could account for delays in dawn song. We suggest that the birds’ ability to change their song timing may be limited by shorter seasonal light variations in tropical areas and by earlier airport activity in studied sites., This work was supported by the Brazilian National Council for Scientific and Technological Development (Conselho Nacional de Desenvolvimento Científico e Tecnológico–CNPq), as part of the “Ciências sem Fronteiras”project, type “Visiting Researcher”(406911/2013-4). DG and JS were supported by funds from researchgrant (CGL2014-55577-R) from the Spanish Ministry of Science to DG. RHM received a fellowship from CNPq for the duration of the study. RDA was supported by scholarships from both CNPq and CAPES (Coordenação de Aperfeiçoamento Pessoal de Nível Superior).

Human induced changes on landscape can alter the biotic and abiotic factors that influence the transmission of vector-borne parasites. To examine how infection rates of vector-transmitted parasites respond to changes on natural landscapes, we captured 330 Blue-black Grassquits (Volatinia jacarina) in Brazilian biomes and assessed the prevalence and diversity of avian haemosporidian parasites (Plasmodium and Haemoproteus) across avian host populations inhabiting environment under different disturbance and climatic conditions. Overall prevalence in Blue-black Grassquits was low (11%) and infection rates exhibited considerable spatial variation, ranging from zero to 39%. Based on genetic divergence of cytochrome b gene, we found two lineages of Haemoproteus (Parahaemoproteus) and 10 of Plasmodium. We showed that Blue-black Grassquit populations inhabiting sites with higher proportion of native vegetation cover were more infected across Brazil. Other landscape metrics (number of water bodies and distance to urban areas) and climatic condition (temperature and precipitation) known to influence vector activity and promote avian malaria transmission did not explain infection probability in Blue-black Grassquit populations. Moreover, breeding season did not explain prevalence across avian host populations. Our findings suggest that avian haemosporidian prevalence and diversity in Blue-black Grassquit populations are determined by recent anthropogenic changes in vegetation cover that may alter microclimate, thus influencing vector activity and parasite transmission.

Building and operating airports are human activities associated with adverse changes in the natural environment, resulting in threats to the biodiversity in airport surroundings. As urban ecosystems are becoming more prevalent in the world and biotic homogenization is a concern, our aim here was to understand how environments near airports (hereafter “airport-affected” sites) were affected, to assess possible changes in bird community structure. We used mist-nets and sound automatic recording units to catalog bird species in natural sites influenced by three Brazilian airports and in three quiet control sites. We characterized study sites by their landscape structure, noise and light levels, and evaluated avian community structure using species richness, abundance and β diversity indexes. Avian communities presented slightly higher species richness in quiet control than in airport-affected sites. Of 22 widespread species, we identified 10 airport adapters responsible for 38.7% of total abundance in airport-affected sites and 17.2% in quiet control sites. We also identified 11 airport avoiders, presenting opposite trends (8.1% and 30.9% respectively). The β diversity results indicate that the regional pool is an important driver in defining species presence within the studied airports. However, taking a wider view, the prevalence of airport adapter species over airport avoider species in the avian communities of airport-affected environments reveals signs of an on-going process of biotic homogenization. Our study provides evidence of the impact of aircrafts and airports on avian communities, a seldom studied anthropogenic change that may affect conservation-worthy areas worldwide., This work was supported by the Brazilian National Council for Scientific and Technological Development (Conselho Nacional de Desenvolvimento Científico e Tecnológico–CNPq), as part of the “Ciências sem Fronteiras” project, type “Visiting Researcher” (406911/2013-4). DG was supported by funds from research grant (CGL2014-55577-R) from the Spanish Ministry of Science to DG. RHM received a fellowship from CNPq for the duration of the study. RDA and GTP were supported by scholarships from both CNPq and CAPES (Coordenação de Aperfeiçoamento Pessoal de Nível Superior).

In order to evaluate the possibility of using this method in the Brazilian Cerrado or other open vegetation areas, we compared the performance of point counts and autonomous recording units (ARU) for avian monitoring. From September to November 2012, we surveyed birds in 13 points established in six localities in central Brazil by using simultaneously ARU and point counts for species presence only comparisons. We identified a total of 84 species and found no significant differences between the number of species obtained by each method. Differing from what we initially expected, few records in point counts were obtained only by visual detection. The number of species registered by ARU corresponded to 90.4% of all observed species. About 92% of the recorded species sang at least once during point counts. Of all species recorded, 17% were not recorded by point counts and 10% were missed by ARU. Jaccard’s index of similarity was 68%. Our results indicate that the ARU can be an effective method to sam...