The high levels of biodiversity in the Amazon are maintained mostly due to its composition as a natural mosaic of different habitats, including both unflooded and flooded forests, campinaranas, and ...savannahs. Here, we compared multiple dimensions of α- and β- bat biodiversity between four natural Amazonian habitats (savannah, campinarana, forest patches, and continuous forest). In addition, we explored the extent to which bat communities in the different habitats are nested within one another, and compared the community-level functional uniqueness and community-weighted mean traits between habitats. Our results show that taxonomic, functional and phylogenetic α-diversity of bats is higher in continuous forest than in any of the other habitat types. The continuous forest also harbours more unique species, and indeed, the bat community assemblages in the less-complex habitats, including forest patches, campinarana and savannahs, are taxonomic, functional and phylogenetic sub-sets of the assemblage found in the continuous forest. By examining β-diversity partitions and species composition, we are able to shed light on the mechanisms behind the variation in diversity between the four habitat types, which reflect a process of environmental sorting along a habitat gradient going from a more complex to a less complex habitat. We conclude that nesting patterns along the mosaic of habitats are determined by differences in complexity between habitats and that taxonomic and functional uniqueness contribute to overall regional bat diversity and functionality. Ongoing human-induced disturbances of these habitats could provoke an unprecedented loss of bat diversity and functionality with negative consequences for biodiversity and ecosystem services.
Aim
We evaluated the relative importance of geographical and environment variables for taxonomic, phylogenetic and functional β‐diversity of phyllostomid bats along the entire Amazon biome and ...specifically in the lowlands.
Location
Amazon biome.
Taxon
Chiroptera.
Methods
We carried out a bibliographic review and compiled a wide and unprecedented database of 106 phyllostomid bat species at 102 sites throughout the Amazon biome. For all possible pairs of sites in both datasets, we estimated the Jaccard pairwise dissimilarity, that is, β‐diversity, considering its three dimensions—taxonomic, phylogenetic and functional—for its two components—turnover (substitution of species) and differences in species richness. The association between dissimilarity measurements and geographical and environment variables was assessed using multiple regressions on distance matrices (MRM).
Results
We found that turnover and differences in species richness had similar contributions to the taxonomic β‐diversity. However, for phylogenetic and functional β‐diversity, lineages and functions richness differences contribute slightly more than turnover for total β‐diversity. In the lowlands, species, lineages and functions richness differences were slightly higher than turnover for all diversity dimensions. When accounting for all the sites, elevation was the main predictor of phyllostomid bats' taxonomic, phylogenetic and functional turnover. For lowland sites, ecoregions was the main (but relatively weak) predictor associated with all β‐diversity dimensions.
Main conclusions
Analysis of filtering sites according to elevation revealed that species in the Amazonian lowlands are taxonomically and phylogenetically different from species in the Andes, and present taxonomic, phylogenetic and functional redundancy between assemblages. When accounting for the whole range of distribution of bats, results showed the predominant effect of elevation over other geographical and environmental predictors. This indicates that the diversity of good dispersers such as bats is more affected by specialisation along environment and climatic gradients than by geographical barriers throughout the Amazon biome.
Gallery forests are important to the maintenance of a substantial portion of the biodiversity in neotropical savanna regions, but management guidelines specific to this forest type are limited. Here, ...we use birds as study group to assess if: (1) functional traits can predict the abundance and occupancy of forest species within a savanna landscape, (2) habitat structures influence the taxonomic, functional, and phylogenetic diversity of forest assemblages, and (3) less diverse gallery forest assemblages are a nested subset of more diverse assemblages living near continuous forests. Then, we propose strategies on how gallery forests can be managed to maintain their species assemblages amidst the fast expansion of human activities across tropical savanna landscapes. We studied 26 sites of gallery forests in an Amazonian savanna landscape and found that: (1) habitat specificity is the only functional trait that predicts species abundance and occupancy across a landscape; (2) phylogenetic diversity is negatively correlated with understory foliage density; (3) the percentage of forests and savannas around sites is positively correlated with both phylogenetic and functional diversity; (4) increasing human activities around gallery forest negatively influences taxonomic and functional diversity; and (5) forest bird assemblages are not distributed at random across the landscape but show a nested pattern caused by selective colonization mediated by habitat filtering. Our combined findings have three implications for the design of conservation strategies for gallery forest bird assemblages. First, maintaining the connectivity between gallery forests and adjacent continuous forests is essential because gallery forest bird assemblages are derived from continuous forest species assemblages. Second, because most species use the savanna matrix to move across the landscape, effectively managing the savanna matrices where gallery forests are embedded is as important to maintaining viable populations of forest bird species as managing the gallery forest themselves. Third, in savanna landscapes planned to be used for agriculture production, protecting gallery forests alone is not enough. Instead, gallery forests should be protected with surrounding savanna buffers to avoid the detrimental effects (edge effects and isolation) of human activities on their biodiversity.
Variations in environmental conditions along gradients play an important role in species distribution through environmental filtering of morphological and physiological traits; however, their effects ...on bat diversity remain poorly understood. Here, we investigate the effect of the distance to the nearest watercourse, terrain elevation, vegetation clutter, basal area and canopy height on taxonomic, functional and phylogenetic diversity and on the predominance of some functional traits (body mass, wing morphology and trophic level) of bat assemblages (phyllostomid and mormoopid bats) in a terra firme forest, in the northeastern Brazilian Amazon. We captured bats using mist nets in 15 permanent plots over a 25 km2 area of continuous forest. We captured 279 individuals belonging to 28 species with a total of 77.760 m2.h of sampling effort. Our results showed that bat richness increases as a function of distance to the nearest watercourse and that the assemblage also changes, with more diverse taxonomic and functional groups in areas further from the watercourse. Furthermore, elevation positively affects species richness, and the basal area of the forest positively influences the average body mass of bats. Taken together, our results demonstrate that subtle variations in the environmental conditions along a local scale gradient impact on the main dimensions of bat diversity in primary forests.
Little is known about the effect of the polymodal tide of the Amazon estuary on the phenology of palms. We evaluated the effect of climate/flood and biotic factors on the phenology of 80 Attalea ...phalerata palms over 1‐year period. Bract emission and young leaves percentage were negatively correlated to accumulated rainfall. Inflorescence and leaf production occurred mainly in the dry season. Immature fruit was positively correlated with rainfall, showing that fruit development occurs during the rainy season. The production of flowers, unripe fruit, and young leaves were positively correlated to flooding. The production of infructescence, per palm, varied from 0 to 4 and 18% of the variance was explained by variables of stem diameter, number of new leaves, altitude, and flood amplitude. The number of infructescence increased for large palms and decreased for individuals subjected to high amplitudes of flooding. These findings reveal that phenological patterns of A. phalerata are driven by seasonal variation in rainfall and flooding. Furthermore, infructescence production can be predicted by plant size and this production is sensitive to variations in flood amplitude. Alteration in rainfall and flooding due to climate change may have a negative impact on fruit production if extreme events increase in frequency.
We evaluated the relationship of climate and Amazon River tide on the phenological patterns of the Attalea phalerata palm. Our main finding shows that river flooding is an important driver that models the reproductive phenophase of this species.
Patterns of detectability and occupation of the jaguar (
Panthera onca
) vary throughout its distribution, being determined primarily by vegetation cover, prey availability, and anthropogenic ...factors. However, there is still a large knowledge gap regarding what determines jaguar occupancy, especially in the Amazon. This knowledge gap is even more pronounced for oceanic islands, which represent unique and very sensitive ecosystems, such as the Maracá-Jipioca Islands of the Northeastern Brazilian Amazon. Our study aimed to establish the spatial ecology of jaguars in this insular ecosystem and to provide information to facilitate sustainable management of the population there. We assessed how different factors (vegetation type and prey availability) potentially influence detectability and occupancy patterns of the jaguars of the Maracá-Jipioca Islands. We found that greater wetland (beach-sea and lagoon-channel) cover was the main driver of jaguar detectability and occupancy. We revealed factors driving the population and spatial ecology of jaguars in an insular system. Despite imminent threats to the region, the knowledge we present can inform the sustainable management of jaguars to ensure that the fundamental and unique ecosystem services provided by this top predator are maintained.
Context
Analyze the multiple dimensions of biodiversity under a local and landscape lens in natural habitats, such as Amazonian savannas, is fundamental for the conservation of species and ...ecosystems.
Objectives
We aim to explore how landscape forest cover and patch-level variables affect the patterns of species abundance, functional traits, and taxonomic, functional and phylogenetic α-diversity of Phyllostomid bats in forest patches of the Savannas of Amapá, in both the wet and dry seasons.
Methods
We used mist nets to survey bats in 26 forest patches. We also quantified forest cover in buffers of 500, 1000, 1500, 2000 and 2500 m around each patch, and tree height, basal area, canopy cover, and vegetation clutter in the understorey at the patch level. We used hierarchical partitioning to relate the different indices with our predictor variables.
Results
Taxonomic, functional and phylogenetic diversity in the wet season increased with the proportion of forest cover in the 2500 m buffer. Vegetation clutter was negatively related to taxonomic and functional diversity in the wet season. In the dry season, average tree height positively affected taxonomic and functional diversity. Patch-level variables were more important than forest cover in explaining the average functional traits in both seasons.
Conclusion
We found seasonal variation in the relationships between components of bat diversity and different drivers. Since both forest cover in the landscape and patch-level variables are important for Phyllostomid bat diversity, conservation plans should consider forest conservation at the landscape level and maintenance of forest patch quality.
We assessed the spatial extent at which the species-landscape relationship is strongest (i.e. the scale of effect—SE) on primate occurrence (
Alouatta belzebul
,
Saguinus midas
,
Saimiri sciureus
, ...and
Sapajus apella
and
Cebus olivaceus
, the last two considered together in the analysis) and species richness and evaluated which landscape, patch, and human variables influence primate distribution in a savanna ecosystem in Brazil. We used nested buffers to measure the landscape attributes, and used these data to assess the SE of the species-landscape relationships. We explored the relative contributions of landscape, patch, and human variables to species richness and occurrences by using Generalized Linear Mixed Models and logistic regression. We found that the SE did not differ between primates, but did between two regions with different matrix composition. At the landscape level, occurrence of all species was higher as the distance to the nearest block of continuous forest decreased, but was lower as the amount of water bodies and anthropogenic cover in the matrix increased. The occurrence of
S. apella
,
C. olivaceus
and
A. belzebul
was positively related to forest cover, and all species but
A. belzebul
had higher occurrence in taller forest. The occurrence of
S. apella
,
C. olivaceus
and
A. belzebul
decreased closer to the city, and
S. apella
and
C. olivaceus
presence increased with the number of residents. Richness was negatively related to the number of residents and anthropogenic cover, but positively to forest height. We concluded that conservation planning for primates should follow a “functional landscape” perspective, by maintaining higher forest cover and minimizing the anthropogenic alterations in the matrix.
ABSTRACT We report an observation of predation by an Amazon tree boa, Corallus hortulanus, on an American fruit-eating bat, Artibeus sp., in an area of seasonal forest close to a small stream in the ...northern Brazilian Amazon. While bats appear to be one of the main food items of C. hortulanus, our observation is only the fourth such event to be recorded in the Brazilian Amazon. The Artibeus sp. individual was observed making distress (agony) calls continuously over a period of three hours, much longer than recorded on previous observations. Records of this type are important to further our knowledge on bat predators, and the defensive behavior of bats.
RESUMO Nós relatamos uma observação de predação por uma serpente Corallus hortulanus sobre um morcego do gênero Artibeus em uma área de floresta estacional perto de um córrego, no norte da Amazônia brasileira. Enquanto os morcegos parecem ser um dos principais itens alimentares de C. hortulanus, a nossa observação representa somente o quarto relato para a Amazônia brasileira. O indivíduo de Artibeus sp. foi observado vocalizando com chamados de distress (agonia) durante um período de três horas, o que representa uma duração muito maior do que o reportado em registros anteriores. Registros deste tipo são extremamente importantes para aumentar o nosso conhecimento sobre os predadores de morcegos e sobre o comportamento de defesa dos morcegos.
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