5 research outputs found
Efectos de la conectividad sobre comunidades de aves forestales de paisajes fragmentados adyacentes
We assessed bird sensitivity to forest fragmentation in two adjacent landscapes in the Atlantic Forest of southern Brazil. One landscape is naturally fragmented and has high connectivity, whereas the other is human-fragmented and has low connectivity. We tested whether the sensitivity of bird species to fragmentation depends more on the intrinsic characteristics of the birds than on landscape connectivity. Point counts were used to sample small and large forest remnants in each landscape. The abundance of each species in these remnants was used as a proxy for sensitivity. To test whether the two landscapes differ in connectivity, we compared the following landscape metrics: landscape shape index (LSI), proximity index (PROX) and connectance index (CONNECT). We analysed the sensitivity of 85 species, 51 of which occurred exclusively in one of the two landscapes. In the landscape with low connectivity we recorded a large number of sensitive species. Among the 34 species that occurred in both landscapes, 24 species (18 non-sensitive and six sensitive) had the same sensitivity. Landscape connectivity seems to be more significant when we focus on the bird communities as a whole. However, when we focus on the same bird species in different landscapes, intrinsic characteristics of species seem to affect their sensitivity to fragmentation more than does landscape connectivity, especially for bird species with lower sensitivity. Therefore, our results show that increasing landscape connectivity may not be the best tool for bird conservation in naturally fragmented landscapes. Nevertheless, it will be important to test further whether forest bird species are more sensitive to environmental degradation in naturally fragmented landscapes than in human-fragmented landscapes.En el presente estudio analizamos la sensibilidad de las aves a la fragmentación del bosque en dos paisajes contiguos de la Mata Atlántica del sur de Brasil. Uno de los paisajes está fragmentado de manera natural y presenta alta conectividad, mientras que en el otro la fragmentación es de origen antrópico y tiene baja conectividad. Evaluamos si la sensibilidad de las especies a la fragmentación depende más de sus características intrínsecas que de la conectividad del paisaje. Usamos puntos de conteo para estimar la abundancia de aves en fragmentos grandes y pequeños en cada paisaje, como un indicador de su sensibilidad a la fragmentación. Para testar si los dos paisajes difieren en conectividad calculamos las siguientes métricas del paisaje: índice de forma del paisaje (LSE), índice de proximidad (PROX) e índice de conectividad (CONNECT). Evaluamos la sensibilidad de 85 especies, de las cuales 51 ocurrieron solamente en uno de los dos paisajes. En el paisaje con baja conectividad registramos un mayor número de especies sensibles. Entre las 34 especies detectadas en los dos paisajes, 24 (18 no sensibles y 6 sensibles) mostraron la misma sensibilidad. Cuando consideramos la comunidad de aves en su conjunto la conectividad del paisaje resulta más relevante, sin embargo, al analizar la misma especie en diferentes paisajes, las características intrínsecas de la especie parecen afectar más su sensibilidad a la fragmentación que la conectividad del paisaje, especialmente en el caso de aves con baja sensibilidad. Nuestros resultados muestran que aumentar la conectividad del paisaje puede no ser la mejor herramienta para la conservación de las aves en paisajes fragmentados de manera natural. No obstante, sería importante estudiar si las aves forestales son más sensibles a la degradación ambiental en paisajes fragmentados naturalmente que en los fragmentados por la actividad humana.The CNPq (Brazilian Research Council) gave us financial support through the Mata Atlântica Program. E. V. Lopes received a PhD scholarship from CNPq during the present study and a sandwich scholarship for a four-month research stay at the Universidad de Alicante in Spain (processes 140353/2006-2 and 202232/2007-7, respectively). L. B. Mendonça received a PhD scholarship from CNPq (process 140317/2006-6). L. dos Anjos received a CNPq research productivity fellowship level 1D (process 305593-2007-2)
Checklist of the birds of Mato Grosso do Sul state, Brazil: diversity and conservation
Several phytogeographic regions (Cerrado, Pantanal, Atlantic Forest, Gran Chaco, and Chiquitano Dry Forests) converge in the state of Mato Grosso do Sul, Brazil, and influence regional biodiversity. Despite a list of birds in the state of Mato Grosso do Sul being published by Nunes et al. (2017), it is necessary to update and critically review avifauna records. In this study, we gathered the results of several records obtained from species lists and online data platforms of the 336 sites in this state over the last decades and grouped them into Main (Primary and Secondary) and Tertiary Lists. The avifauna of Mato Grosso do Sul is composed of 678 species, of which 643 (95%) have records proving their occurrence (Primary List), whereas 34 still lack documentation (Secondary List). The number of related species for Mato Grosso do Sul represents 34% of the Brazilian avifauna. Some species stand out for their unique occurrence in Mato Grosso do Sul, such as Melanerpes cactorum, Celeus lugubris, Phaethornis subochraceus, and Cantorchilus guarayanus, reflecting the influence of different phytogeographic regions of the Chaco and Chiquitano Dry Forests. Migrants represent 20% of the bird community occurring in the state, of which 93 species correspond to migrants from various regions of South America (south and west) and 40 to boreal migrants. Thirty-three species perform nomadic movements across the Pantanal Plain and other regions of the state. Thirty-one species are included in some conservation-threatened categories of global and/or national endangered species lists. Other 30 species are included in the near-threatened category at the global level and 23 at the national level. In addition, species typical of dry forests (in Serra da Bodoquena and Maciço do Urucum) and those from the Atlantic Forest in the south of the state deserve attention due to their restricted distribution and the high anthropogenic pressure on their habitat
Checklist of the birds of Mato Grosso do Sul state, Brazil: diversity and conservation
Several phytogeographic regions (Cerrado, Pantanal, Atlantic Forest, Gran Chaco, and Chiquitano Dry Forests) converge in the state of Mato Grosso do Sul, Brazil, and influence regional biodiversity. Despite a list of birds in the state of Mato Grosso do Sul being published by Nunes et al. (2017), it is necessary to update and critically review avifauna records. In this study, we gathered the results of several records obtained from species lists and online data platforms of the 336 sites in this state over the last decades and grouped them into Main (Primary and Secondary) and Tertiary Lists. The avifauna of Mato Grosso do Sul is composed of 678 species, of which 643 (95%) have records proving their occurrence (Primary List), whereas 34 still lack documentation (Secondary List). The number of related species for Mato Grosso do Sul represents 34% of the Brazilian avifauna. Some species stand out for their unique occurrence in Mato Grosso do Sul, such as Melanerpes cactorum, Celeus lugubris, Phaethornis subochraceus, and Cantorchilus guarayanus, reflecting the influence of different phytogeographic regions of the Chaco and Chiquitano Dry Forests. Migrants represent 20% of the bird community occurring in the state, of which 93 species correspond to migrants from various regions of South America (south and west) and 40 to boreal migrants. Thirty-three species perform nomadic movements across the Pantanal Plain and other regions of the state. Thirty-one species are included in some conservation-threatened categories of global and/or national endangered species lists. Other 30 species are included in the near-threatened category at the global level and 23 at the national level. In addition, species typical of dry forests (in Serra da Bodoquena and Maciço do Urucum) and those from the Atlantic Forest in the south of the state deserve attention due to their restricted distribution and the high anthropogenic pressure on their habitat