RESUMO As aves são conhecidas por desempenharem um importante papel na reprodução de diversas espécies de plantas através da frugivoria e dispersão de sementes. Apesar da importância das cactáceas em ambientes sazonais, poucos estudos avaliaram interações entre essas plantas e aves frugívoras. O presente trabalho identificou as espécies de aves que se alimentam dos frutos de Cereus jamacaru D. C. (1828), Pilosocereus gounellei (F. A. C. Weber) Byles & G. D. Rowley (1957) subsp. gounellei, Pilosocereus pachycladus (F. Ritter), Kakteen Südamerika, (1979) e Pilosocereus tuberculatus (Werderm.) Byles & Rowley (1957) e estimou potenciais dispersoras das sementes. O estudo foi desenvolvido no Parque Nacional do Catimbau, localizado no sertão do Estado de Pernambuco, entre fevereiro de 2017 e agosto de 2017. Em 78 horas de observação focal nas espécies vegetais, foram registradas 20 espécies de aves pertencentes a 11 famílias consumindo polpa das quatro espécies de cactáceas. A composição de aves visitantes variou conforme a espécie de cactáceas. As espécies de aves consideradas potenciais dispersoras foram Tachyphonus rufus (Boddaert, 1783), Tangara sayaca (Linnaeus, 1766), Paroaria dominicana (Linnaeus, 1758) e Mimus saturninus (Lichtenstein, 1823). Pilosocereus tuberculatus foi visitada apenas por Forpus xanthopterygius (Spix, 1824). Este é o primeiro estudo a identificar aves atuando como frugívoras e potenciais dispersoras de P. pachycladus e P. tuberculatus. Adicionalmente, nosso estudo destaca as aves frugívoras e onívoras como principais potenciais dispersores de C. jamacaru, P. pachycladus e P. gounellei subsp. gounellei.
Mobbing represents a well‐known anti‐predatory behavior, where potential prey display aggressively against a predator. Despite considerable experimental and descriptive work, no models predict species participation in mobbing assemblages. Here, we aimed to understand why some bird species engage in this behavior, while others do not, and what factors can be used to predict mobbing engagement within an avian community. We investigated whether certain functional traits, such as body size, foraging guild, foraging mode, and strata, as well species abundance and evolutionary relatedness, are important mobbing predictors. To address these goals, we simulated the presence of the Ferruginous Pygmy‐Owl (Glaucidium brasilianum) by broadcasting its voice in 230 experiments conducted in 115 points, systematically distributed in a dry forest of northeastern Brazil. We compared these results to 162 avian surveys (point counts) conducted in the same area. Our avian surveys detected 108 bird species (local avian community), whereas our playback experiments attracted 72 species (mobbing assemblage). In general, small, canopy insectivorous or frugivorous birds dominated the mobs. The best mobbing predictors were body mass and guild, whereas species abundance, foraging mode, and strata were not retained in the best models. We found a strong phylogenetic component in body mass and mobbing propensity (almost 90% of the species and individuals participating in the mobs were passerines). At the community level, we found significant differences in the functional and phylogenetic structure of the mobbing assemblage in relation to the avian community. Our results suggest that mobbing behavior is tightly associated with predation risk and the capacity of individual species to find and detect predators, and that functional and phylogenetic features can predict species participation in this complex animal behavior.
Summary The carrasco is a dense, shrubby vegetation type that covers the higher parts of table-top mountains in north-eastern Brazil. The vegetation of this phytophysiognomy is often considered to have biogeographical and ecological affinities with the cerrado of Central Brazil, but the biogeographical affinities of its avifauna remain unclear. In recent years, deforestation due to local economic activities has been particularly severe in some carrasco-dominated landscapes. In 2013, we initiated avian surveys at the Fazenda Pau D‘Arco, a privately owned property located on top of the Araripe Plateau, to evaluate the effects of a legal forest management program on the avifauna. Here, we present the results of four years of avian inventories to: i) characterize a well-preserved patch of carrasco vegetation; ii) assess avian biogeographical affinities of this vegetation type; iii) identify associations between managed/unmanaged areas and bird species; and iv) provide baseline data for future avian monitoring studies. Using different survey methods, we provide a list of 148 bird species, including several dry-forest specialists and caatinga endemics. Biogeographically, the avifauna of the carrasco represents a subsample of the Caatinga dry forest, lacking cerrado elements. Forest management significantly affected the distribution of several bird species in the study area. We found that 1/5 of the species (24) recorded during our standardized surveys were significantly associated with either unmanaged (14 species) or managed (10 species) areas. Species such as the Ceará Leaftosser Sclerurus cearensis, a globally vulnerable species, have only been detected in non-managed areas and therefore can be negatively affected by the management program. We also present data on 16 avian taxa with ecological and conservation concerns. By presenting a fairly complete and documented list of the avifauna, we characterize the carrasco avifauna and offer the tools to evaluate the effects of forest management on this poorly known vegetation type.
Several studies suggest that Cyanopsitta spixii occurs mainly in Tabebuia caraiba (Mart.) Bureau gallery woodlands of northern Bahia (Brazil). The recently creation of two Protected Areas (2018) is combining efforts to ensure the reintroduction and conservation of this Critically Endangered (Possibly Extinct in the Wild) macaw. Achieving species conservation requires the definition of priority conservation areas and habitat recovery and the Landscape Cartography can be a relevant tool for this purpose. This research aimed to verify if there is a correlation between Landscape Units map and the Spix’s macaw occurrence. Here the Protected Areas landscape is described in three main components: land cover, landforms and superficial geology and then overlapped to occurrence map of Spix’s macaw and its most similar syntopic parrot, Primolius maracana. Spatial correlation revealed a correspondence of 85.48% to Dry River Environment Landscape pattern and C. spixii occurrence, indicating the importance to prioritize fluvial Landscapes conservation, combined with conservation strategies that must include the local population, since this are important territories for their survival.
The conversion of tropical habitats has dramatic implications on biodiversity and represents one of the greatest conservation challenges of our time. Seasonally Dry Tropical Forests (SDTF), which are disjointly distributed throughout the Neotropics, are especially susceptible to human activities. The Caatinga Dry Forest, located in the semi-arid interior of northeastern Brazil, represents not only the largest and most biologically diverse nucleus of SDTF, but also the world’s most densely populated semi-arid region, with ever-growing pressure on its natural resources. To prevent illegal logging, conservation agencies looked at forest management, where an area is divided in smaller stands which are gradually logged and allowed to regrow for a period of time, when a new cutting cycle should reinitiate. The impacts of these management schemes on biodiversity, however, remain largely untested. We conducted standardized avian surveys to evaluate the effects of forest management on the avian community at a 1,670 ha privately owned property located on the Chapada do Araripe, northeastern Brazil. This area was divided in 22 forest stands, half of which had already been logged at the time of our sampling, creating a gradient of logged and natural forests and an 11-yr chrono-sequence of forest regeneration. Our results show that logged areas present fewer individuals, fewer species, and different avian assemblages than unlogged forests. Such differences are mostly driven by forest-dependent species, which were overwhelmingly affected by forest management. Our results show that although logged forests tend to recover its height after a decade, they do not recover the originally forest cover, measured by the Normalized Difference Vegetation Index. Likewise, decade-long recovering stands continue to show lower species richness, lower bird abundance, and different avian composition than unlogged forests. We identified a set of bird species that are more affected by forest management (ecological losers) and a group of birds that apparently benefit from the referred changes in land use (ecological winners). We conclude that completely managing an entire area may cause the extirpation of several forest-dependent species. We therefore suggest keeping logged and unlogged plots intermingled, to avoid local extinctions and the complete modification of the original avifauna.
The Caatinga, the largest region of seasonally dry tropical forest in the Neotropics, suffers high rates of deforestation and habitat degradation, mostly due to wood extraction. As an alternative to illegal logging, governments have looked at more sustainable management schemes, allowing natural regeneration after logging through relatively long (~25-year) harvest rotations. We investigated the impacts of forest management at a 1,700-ha privately owned area located at the Araripe Plateau, in the semiarid interior of northeastern Brazil, focusing on the population parameters of 8 avian species. The property was subdivided into 22 forest stands, where a different stand has been logged every year since 2004. By 2016, when we sampled the avifauna, 12 forest stands had already been logged and allowed to regrow, creating a landscape of logged and unlogged stands and a 12-year forest recovery chrono-sequence. We conducted distance-based sampling along transects to estimate the density and abundance of these species in logged and unlogged stands. We found that logging impacted 3 of the target species. Two of them (Megaxenops parnaguae and Synallaxis scutata) were less abundant, whereas another (Sclerurus cearensis) disappeared altogether from logged areas. We also found a positive correlation between the normalized difference vegetation index (NDVI) and the avian density of the affected species. However, we failed to observe any significant relationship between forest recovery or NDVI and species densities, suggesting that even after 12 years of forest recovery, species abundance remains lower in logged than in unlogged areas. We found that logging impacted birds in a species-specific manner, with 5 species unaffected and 3 species declining. Although our sampling occurred half-way through the regeneration cycle, we found no evidence of recovery for those species most affected. We suggest keeping unlogged areas intermingled with logged stands, allowing the survival and potential recovery of species in regenerating forests.
As primary decomposers of organic matter, mucoralean fungi have an important ecological role in edaphic systems in the Atlantic Forest. However, there is a knowledge gap regarding how communities of Mucorales are structured in soils of Atlantic Forest areas, and whether these communities are influenced by edaphic attributes in this domain. Thus, the current study aimed to understand the influence of edaphic attributes linked to species richness, abundance and composition of Mucorales in dense ombrophilous forest, 'tabuleiro' forest, sandbank and mangrove ecosystems located in Pernambuco, Brazil. Altogether, twenty-three taxa, including seven new records, were reported from soil samples from the ecosystems. Species composition was similar among the ecosystems, except for mangrove, while species richness and diversity of Mucorales were highest in dense ombrophilous forest and 'tabuleiro'. Together the soil variables were responsible for 35.5 % of the variation in species composition, with pH being responsible for 53.32 % and 47.24 % of the variation in richness and abundance of these communities, respectively. These data indicate that pH is the most important attribute in delimiting the structure of mucoralean communities in the study areas, with influence on the composition, richness, and abundance of these fungi.
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