THE DEGREE OF FRUGIVORY OF BIRDS AS ESTIMATED FROM GASTRIC AND FECAL SAMPLES

The degree of frugivory (DF) has long been used to characterize the relative importance of fruits to the diet of a bird and, more recently, as a functional trait related to the role of birds in seed dispersal networks. Although quantitative estimations of DF are desirable, general, categorical classifications or coarse estimations of diet composition based in qualitative information are often used. Data on stomach, fecal and regurgitation contents scattered in the literature or easily obtained in the field could be used to provide a quantitative, potentially more reliable assessment of DF. We compiled such data from the literature and our own fieldwork to obtain 12,576 samples for 985 Neotropical bird species, of which 489 species (49.6%) from 61 families had at least one fruit-containing sample. Gastric (i.e. stomach plus regurgitation) and fecal samples provided similar estimates of DF, despite potential differences in the degree of food digestion. The DF we obtained were higher than those presented in the most frequently used source of quantitative DF estimates in the literature (the Elton Traits database). We further explored with a few study cases the utility of stomach, fecal and regurgitation samples to evaluate intraspecific geographic, sexual, and ontogenetic variations in DF, topics rarely investigated so far. We argued that stomach, fecal and regurgitation sample data abundantly available in the literature or obtained from mist-netted birds may be used to produce quantitative assessments of DF likely more reliable than the estimates used so far and useful for a plethora of ecological studies

Verde perto educação

A obra é uma metodologia de educação ambiental e científica que utiliza arte, ciência, cultura e estimulo ao protagonismo. Estruturado a partir do estímulo as múltiplas inteligências, a interdisciplinaridade, a educação lúdica e o exercício do protagonismo no ato de ensino aprendizagem.O livro traz o histórico e descrição da metodologia além da visão de diferentes profissionais sobre essa forma de realizar educação e a descrição de diferentes experiências da aplicação da metodologia no Brasil

Effects of Forest Fragmentation on Feather Corticosterone Levels in an Amazonian Avian Community

Summary . In the Amazon, the construction of hydroelectric dams is an emergent driver of biodiversity loss, creating numerous land-bridge islands, most of them unable to sustain an assemblage of bird species comparable to the intact forest. Although we understand the effects of forest fragmentation on species richness and distribution, we still need to uncover the physiological mechanisms underlying the success of organisms living in disturbed habitats. In this study, we used feather corticosterone levels as a measurement of physiological indicators of stress, evaluating whether corticosterone levels mirror the effects of habitat fragmentation on species occurrence. Since data suggest that smaller islands can reduce habitat suitability, increasing stress in birds that live within them, we predicted that birds living in smaller islands would present increased feather corticosterone levels. We captured birds in 13 islands of varying size and in two continuous forests and analysed feather corticosterone levels of 265 individuals from eight different species. Overall, our findings did not support the hypothesis that corticosterone varies in relation to island size, except for the Guianan Antwarbler Hypocnemis cantator, which presented the predicted pattern: decreasing feather corticosterone levels with increasing island size. These differences suggest that species respond differently to stressors driven by fragmentation. Further studies are necessary to assess the reliability of corticosterone levels as a physiological measurement of stress and to determine which parameters are useful to understand how insularisation caused by human activities may influence the resistance of avian populations to habitat disturbances. - Bicudo, T., Anciães, M., Arregui, L. & Gil, D. (2020). Effects of forest fragmentation on feather corticosterone levels in an Amazonian avian community. Ardeola, 67: 229-245.We also thank the National Council for Scientific and Technological Development – CNPq, for the Ciência sem Fronteiras scholarship to T.B. DG's research in Brazil was supported by a Ciência sem Fronteiras (CNPq) grant to Regina Macedo. DG was additionally funded by a grant from the Ministerio de Economía y Competitividad (CGL2014-55577R). TB receive a PhD scholarship from CAPES

Disentangling the drivers of reduced long-distance seed dispersal by birds in an experimentally fragmented landscape

Seed dispersal is a crucial component of plant population dynamics. Human landscape modifications, such as habitat destruction and fragmentation, can alter the abundance of fruiting plants and animal dispersers, foraging rates, vector movement, and the composition of the disperser community, all of which can singly or in concert affect seed dispersal. Here, we quantify and tease apart the effects of landscape configuration, namely, fragmentation of primary forest and the composition of the surrounding forest matrix, on individual components of seed dispersal of Heliconia acuminata, an Amazonian understory herb. First we identified the effects of landscape configuration on the abundance of fruiting plants and six bird disperser species. Although highly variable in space and time, densities of fruiting plants were similar in continuous forest and fragments. However, the two largest-bodied avian dispersers were less common or absent in small fragments. Second, we determined whether fragmentation affected foraging rates. Fruit removal rates were similar and very high across the landscape, suggesting that Heliconia fruits are a key resource for small frugivores in this landscape. Third, we used radiotelemetry and statistical models to quantify how landscape configuration influences vector movement patterns. Bird dispersers flew farther and faster, and perched longer in primary relative to secondary forests. One species also altered its movement direction in response to habitat boundaries between primary and secondary forests. Finally, we parameterized a simulation model linking data on fruit density and disperser abundance and behavior with empirical estimates of seed retention times to generate seed dispersal patterns in two hypothetical landscapes. Despite clear changes in bird movement in response to landscape configuration, our simulations demonstrate that these differences had negligible effects on dispersal distances. However, small fragments had reduced densities of Turdus albicollis, the largest-bodied disperser and the only one to both regurgitate and defecate seeds. This change in Turdus abundance acted together with lower numbers of fruiting plants in small fragments to decrease the probability of long-distance dispersal events from small patches. These findings emphasize the importance of foraging style for seed dispersal and highlight the primacy of habitat size relative to spatial configuration in preserving biotic interactions

Modelagem de nicho ecológico na prática: Espécies bandeira e planejamento para conservação regional

Conservation of rare or endemic species is a multifaceted matter, especially whenever knowledge gaps in species' distribution and anthropogenic pressures converge. We combined Geographic Information Systems and ecological niche modeling tools with field data to characterize the habitat types used for different behavioral activities and to identify important areas for conservation of a charismatic bird endemic to northeast South America, the Guianan cock-of-the-rock (Rupicola rupicola). Using species' occurrences and climatic, topographic, and remotely sensed vegetation variables we developed potential distribution models at two scales: (1) broad geographic scale (northern South America), based on georeferenced occurrences obtained from literature and natural history museum specimens, and (2) local scale, based on precise occurrences (GPS coordinates) recorded in the field (Caverna do Maroaga Protected Area, Amazonas, Brazil). We identified six priority areas for the conservation of the cock-of-the-rock corresponding to high environmental suitability and lowest anthropogenic pressure, measured as distance from urban areas and highways (>5 km). Protecting the areas identified in this study from anthropogenic threats such as hunting and selective logging will help to preserve not only the cock-of-the-rock, but also the biodiversity of the whole mosaic of habitats in the region. Our results were incorporated in a regional management plan developed by state agencies and non-governmental organizations. Geographic Information Systems and ecological niche modeling techniques combined with on the ground, local surveys can be useful in species conservation efforts, for planning new inventories, prioritizing areas to be protected, and for creating ecological corridors

Use of secondary forests by understory birds in a fragmented landscape in central Amazonia

Rates of deforestation in the Brazilian Amazon have increased since 1991 and forecasts are not optimistic about the slowing of this process. Some authors believe that the Amazon may be experiencing a massive process of species extinction. However, the deforestation is accompanied by the expansion of secondary forests that are established in the abandoned areas. The trend is an increase in secondary forests cover, resulting in a mosaic of primary forest (FP) and fragments separated by an array of secondary forests (FS). In this scenario, the prediction of a massive extinction could be wrong if many species could survive in the secondary forests. To assess the importance of FS for the understory birds we sampled areas in regeneration and a continuous forest of a fragmented landscape. We conducted mist netting (24 nets/day) for six consecutive days/month, for 8 months (May-November) in 2009. Some forest species as do not seem to be adapted to the secondary forest environment and their occurrences are restricted to continuous forest environments. But most focal species showed no significant difference in apparent survival rates between the enviroments, suggesting that these species inhabit the secondary forest and the primary forest similarly. Because most of the matrix in fragmented landscapes are composed by secondary forests, such results highlights the conservation value that these habitats present in the long term. Thus, FS should be regarded as dynamic matrix that not only allows the movement of individuals but also function as habitat for many species typical of FP.Na Amazônia, as taxas de desmatamento crescem desde 1991 e as previsões não são otimistas quanto à desaceleração desse processo. A devastação da floresta é acompanhada de uma expansão de florestas secundárias (FS) que se estabelecem nas áreas abandonadas. A tendência é um aumento de florestas secundárias, resultando num mosaico de floresta contínua e fragmentos separados por uma matriz de FS. Nesse cenário, autores acreditam que a Amazônia pode passar por um processo massivo de extinção de espécies. Por outro lado, a previsão de um processo massivo de extinção pode ser equivocada, pois muitas espécies florestais poderiam sobreviver nas florestas secundárias. Para avaliar o valor das florestas secundárias para espécies florestais amostramos por oito meses com redes de neblina uma capoeira (FS) em regeneração e uma floresta primária (FP) de uma paisagem fragmentada. Algumas espécies não foram capturadas na capoeira e aparentemente evitam esse tipo de hábitat. No entanto, a maioria das espécies do grupo focal não apresentou diferença na sobrevivência aparente entre os ambientes, o que nos indica que estão habitando a capoeira e a floresta primária da mesma forma. Na realidade amazônica, onde grande parte da matriz é composta por floresta secundária, a matriz tem valor para conservação e deve ser analisada como um elemento dinâmico que não apenas permite a movimentação de indivíduos, mas também serve de hábitat para muitas espécies de floresta primária. Mas ressaltamos que é fundamental a preservação de áreas de floresta primária que servirão de fonte às florestas secundárias adjacentes

Effects of forest fragmentation on the lekking behavior of White-throated Manakins in Central Amazonia

Forest fragmentation can affect various aspects of population dynamics, but few investigators have assessed possible effects on the behavior of a species. Loss of habitat may limit population recruitment and abundance, which may alter breeding dynamics in forest remnants. We examined the lekking behavior of White-throated Manakins (Corapipo gutturalis) in a fragmented landscape to determine if forest fragmentation affected the spatial distribution of display courts and male behavior at courts. We captured and observed males at 19 courts located in 11 primary forests of different sizes in forest habitats of the Biological Dynamics of Forest Fragments Project area, an experimentally fragmented landscape located in the central Brazilian Amazon, and estimated their spatial distribution as the distance to the nearest court in the landscape. We quantified habitat loss using the proportion of forest cover surrounding courts and their distances to forest edges. No courts were detected in 1-ha forest fragments, suggesting direct effects from habitat loss following fragmentation that affected connectivity and thus recruitment and persistence of courts in the smallest fragments. The spatial distribution of display courts in forests larger than 10 ha remained unaltered, compared to display courts in continuous forests, but adult males were less numerous on courts with a higher percentage of forest cover and they displayed less on courts closer to forest edges. The spatial distribution of courts also contributed to variation in male social behavior, with more juvenile males present and adult males displaying at lower rates at more isolated courts. Although White-throated Manakins are locally common, the observed behavioral changes in response to habitat loss may affect their population dynamics. Our results show the importance of assessing behavioral changes in conservation programs and, in particular, of including biologically relevant measures of habitat loss in addressing its possible effects on species persistence in fragmented landscapes. © 2020 Association of Field Ornithologist

Ecological niches and their evolution among neotropical manakins (Aves: Pipridae)

Study of the evolution of ecological characteristics using phylogenetic information is only beginning, but several new tools and approaches open fascinating possibilities. The Pipridae is a diverse and well-known family of frugivorous birds that are easily sampled and that are broadly distributed across many Neotropical environments, and as such are appropriate for studies of ecological niche evolution. Using known occurrences and climate and topography data sets, we modeled ecological niches for each species in the family, and carried out analyses aimed at describing ecological niches of manakins and understanding historical patterns of ecological change in the family. Most species' ecological niches were characterized by warm and relatively humid conditions, reflecting the great diversification of the family in lowland and montane forests of western South America. Ecological niche evolution was in general conservative, with most sister species pairs being closely similar ecologically, indicating that isolation rather than adaptation to new ecological conditions has dominated the diversification in this family. Exceptions to this pattern represent interesting foci for future research, whereas studies of ecological niches focusing on past distributions of manakins will allow further biogeographic inferences. © 2009 Journal of Avian Biology