Search Results (79)

In northwestern Ecuador, where more than 90% of the original forest cover has been lost, it is unknown how soil chemistry influences bat diversity. This study evaluated bat diversity, non-herbaceous plant community structure, and soil nutrients in 30 plots distributed across crops on two farms separated by 32 km. Soil analyses revealed variations in organic matter and nutrients, identifying calcium, magnesium, zinc and iron as the most influential. A total of 1662 individuals of 24 non-herbaceous plant species and 193 individuals of 16 bat species were recorded, dominated by frugivorous and nectarivorous guilds. Generalized linear mixed models showed significant relationships between bat diversity indices and soil nutrients. These elements improve tree growth, fruiting, and flowering, which increases the quality and availability of food resources for bats. In return, these mammals provide key ecosystem services such as pollination, seed dispersal, and insect control. Our findings highlight that soil chemistry indirectly regulates bat communities by influencing vegetation structure and resource availability. This integrated approach underscores the importance of soil–plant–animal interactions in tropical agricultural landscapes, offering practical guidance. Full article

Elevational variation in avian community composition can be significantly influenced by habitat degradation, fragmentation and secondary forest growth. Few studies have identified the drivers of changes in bird community composition across disturbed montane elevational gradients of smaller tropical islands. We examined patterns of avian diversity using long-term mist-net data (2008–2014) across three different forest elevations along a tropical montane elevational gradient in the Northern Range of Trinidad, West Indies. All three sites (lowland mature secondary forest, mid-elevation highly disturbed secondary forest, and undisturbed high elevation forest) were found to have distinctive bird communities. Turnover rather than nestedness explained most of the total dissimilarity between sites. Whilst some turnover could be attributed to elevation, changes to diversity at the mid-elevation site result more from local habitat heterogeneity related to human activities and secondary growth, with increased species richness attributable to habitat-generalist species indicative of disturbance. Significant anti-nestedness in species occupancy was observed, underpinned by the loss of ground-dwelling and understory insectivores from the mid-elevation site. Differences in bird community composition, in contrast, were driven by the abundance of specialist nectarivores in the highest elevation undisturbed montane forest, and by generalist nectarivores and frugivores at lower elevations. Full article

Uganda is home to a rich diversity of bats, which carry high ecological and socioeconomic value through the ecosystem services that they provide. However, critical bat habitats, including caves, are facing increasing anthropogenic pressures, and the types and frequencies of disturbances to cave-roosting bats are not well understood in Uganda. Therefore, we examined the role of anthropogenic disturbances in caves to assess the threats posed to bat populations. We used the Bat Cave Vulnerability Index (BCVI) framework to score 14 caves inhabited by bats within the study region. We included qualitative surveys with human communities to better understand various aspects within the BCVI. All bat species recorded were of the IUCN category “Least Concern”. The BCVI indicated 50% of the caves (with insectivorous and frugivorous bats) require urgent conservation interventions due to high bat diversity and anthropogenic disturbances (e.g., guano collection). Most of the caves studied were highly vulnerable to anthropogenic disturbances, as assessed in the study. All the caves we studied (except two) are outside the protected area, and due to their imputed vulnerabilities, interventions ought to be implemented to balance cave conservation and human use in the Mt. Elgon area. Such interventions should integrate human factors. Full article

Bird–plant interactions are critical for maintaining biodiversity and ecosystem function, and represent a key research focus in modern ecology. Using the line transect method, we surveyed bird diversity and collected plant trait data in four habitat types in the southern zone of Fujian’s Meihuashan National Nature Reserve during October–December 2021 and July–August 2022. This study investigated how plant traits (tree height, diameter at breast height (DBH), canopy density fruit amount) influence the diversity of frugivorous birds (species richness, abundance, Shannon–Wiener, Pielou, Simpson) across four disturbed habitats—villages (residential areas), bamboo forests (economic plantations), unguarded broad-leafed forests (wild forests), and nurtured broad-leafed forests (managed forests)—during both summer (breeding season) and autumn–winter (fruiting season). The key findings revealed that (1) significant correlations between plant traits and bird diversity were exclusive to the fruiting season, with no associations found in summer; (2) during autumn–winter, the key plant traits driving bird diversity varied distinctively by habitat: tree height and canopy density were paramount in villages; both habitat structure (canopy density) and fruit amount were important in bamboo forests, whereas in both broad-leafed forests, a combination of tree structure (height, DBH, canopy density) and fruit amount determined bird abundance; (3) a significant interaction between season and habitat was detected for community evenness, indicating that habitat type modulates the seasonal effects on community composition. This study underscores that in human-modified landscapes, conserving habitat structural complexity and key resource plants is crucial for sustaining frugivorous bird diversity and its ecological functions. Conservation strategies must account for seasonal dynamics to be effective. Full article

Urbanization affects bird communities by reducing habitat and fragmenting ecosystems. Urban parks can help counteract these effects. However, anthropogenic noise can further alter bird composition. We examined the distribution and abundance of bird species in nine urban parks in Mexico City. We used a ten minute fixed-radius (25 m) point-counting technique to count birds along their annual cycle, with ten minutes allocated for bird counts. The quality of green areas was analyzed in terms of vegetation (Normalized Difference Vegetation Index), park size, and mean noise level dB(A) (based on MIN and MAX values), and species were grouped into trophic guilds. A total of 108 bird species were recorded, 5 of which are under special protection; we grouped all species into 14 trophic guilds, showing different responses to environmental gradients. Redundancy analysis (RDA) explained 89.98% of the variance, with noise and park size being the most influential variables. Granivores and omnivores were more tolerant to noise, while insectivores and frugivores preferred quieter areas with more vegetation. A positive association was observed between the presence of winter resident species and the park size. On the other hand, mean noise level dB(A) was negatively related to permanent resident species, winter resident species, and those with protected status. Conservation efforts should focus on maintaining ample green spaces and reducing noise pollution, as recorded high mean noise levels (>53 dB(A)) exceed the recommended thresholds for avifauna conservation. Full article

Habitat loss and land-use intensification are major threats to biodiversity in the Brazilian Atlantic Forest, particularly for bat assemblages that provide key ecosystem services. In this study, we examined how landscape composition (forest and pasture cover) and local forest structure influence the richness and abundance of phyllostomid bats across 20 forest fragments in southern Bahia. Bat sampling was conducted using mist nets, and forest structure was quantified using tree measurements and vertical foliage stratification. We applied structural equation modeling to test the direct and indirect effects of landscape and local variables. Our results show that forest cover has both direct and indirect positive effects on bat diversity, mediated by improved forest structure. In contrast, increased pasture cover negatively affected forest structure and was weakly associated with bat diversity. The most abundant species were generalist frugivores, such as Carollia perspicillata and Rhinophylla pumilio. These findings highlight the importance of maintaining forest cover and structural complexity to support bat diversity in agroforestry-dominated landscapes. Conservation strategies that integrate habitat protection with sustainable land-use practices are crucial to maintaining biodiversity and the ecological functions provided by bats in this globally threatened biome. Full article

Biological studies on symmetry can be expanded to consider red (longer wavelengths) and blue (shorter wavelengths) shifts as antisymmetries (opposite-pattern symmetries), which may arise from similar underlying causes (invariant process symmetries). In this context, classic shift asymmetries of redder plumage in response to higher dietary carotenoids appear conceptually incomplete, as potential blue-shifted counterparts were not considered. A latent symmetric response is highlighted by recent evidence showing that the maximum absorbance bands of various colorful plumage pigments are red-shifted in birds with ultraviolet-sensitive (UVS) color vision but blue-shifted in those with violet-sensitive (VS) color vision. Blue-shifted responses to increased dietary carotenoid contents may also be underestimated, as relevant studies have focused on species-rich but uniformly UVS Passerida passerines. This study explored the relationship between pattern–process symmetries and diets of VS Piciformes–Coraciiformes by gauging the responses of their plumage reflectance to a modified diet index (Diet_c), where the overall rank carotenoid contents of food items were weight-averaged by three levels of importance in a species’ diet. In the case of both sexes, the main long-wavelength reflectance band for the three carotenoid-based pigment classes defined the same graded series of blue shifts in response to higher Diet_c. Yellow showed a strong absolute (negative slope) blue shift, orange showed a weaker absolute blue shift, and red exhibited only a blue shift (flat, non-significant slope) relative to absolute red shifts (positive slope). The secondary shorter-wavelength reflectance band was also unresponsive to Diet_c in the VS Piciformes–Coraciiformes (relative blue shift) compared with earlier evidence for it decreasing (absolute red shift) at higher Diet_c in UVS species. Results for the intervening minimum reflectance (maximum absorbance) band were intermediate between those for the other reflectance bands. No pigment class monopolized lower or higher Diet_c, but red was less variable overall. Phylogenetic independence, sexually similar responses, and specimen preservation reinforced characterizations. A review of avian perceptual studies suggested that VS models discriminate yellows and oranges extremely well, consistent with the importance of the corresponding carotenoids as Diet_c indicators. Both UVS and VS species appear to produce putatively more costly and possibly beneficial carotenoid metabolites and/or concentrations in response to higher Diet_c, supporting underlying invariant processes in relation to carotenoid limitations and honest signaling despite opposite plumage shifts and their different chemical bases. In symmetry parlance, pigment classes (red) or wavebands (short) that lack responses to Diet_c suggest broken pattern and process symmetry. The biology of VS Piciformes–Coraciiformes may favor such exceptions owing to selection for visual resemblance and tuning specializations, although universal constraints on physical and chemical properties of (particularly red) carotenoids may favor certain functional tendencies. Thus, symmetry principles organize carotenoid diversity into a simplified and predictive framework linked to color vision. Full article

Background/Objectives: In South China, Lithocarpus species dominate mixed evergreen broadleaf forests, forming symbiotic relationships with ectomycorrhizal fungi and serving as food resources for diverse fauna, including frugivorous birds and mammals. The limited understanding of chloroplast genomes in this genus restricts our insights into its species diversity. This study investigates the chloroplast genome (cp genome) sequences from seven Lithocarpus species, aims to elucidate their structural variation, evolutionary relationships, and functional gene content to provide effective support for future genetic conservation and breeding efforts. Methods: We isolated total DNA from fresh leaves and sequenced the complete cp genomes of these samples. To develop a genomic resource and clarify the evolutionary relationships within Lithocarpus species, comparative chloroplast genome studies and phylogenetic investigations were performed. Results: All studied species exhibited a conserved quadripartite chloroplast genome structure, with sizes ranging from 161,495 to 163,880 bp. Genome annotation revealed 130 functional genes and a GC content of 36.72–37.76%. Codon usage analysis showed a predominance of leucine-encoding codons. Our analysis identified 322 simple sequence repeats (SSRs), which were predominantly palindromic in structure (82.3%). All eight species exhibited the same 19 SSR categories in similar proportions. Eight highly variable regions (ndhF, ycf1, trnS-trnG-exon1, trnk(exon1)-rps16(exon2), rps16(exon2), rbcL-accD, and ccsA-ndh) have been identified, which could be valuable as molecular markers in future studies on the population genetics and phylogeography of this genus. The phylogeny tree provided critical insights into the evolutionary trajectory of Fagaceae, suggesting that Lithocarpus was strongly supported as monophyletic, while Quercus was inferred to be polyphyletic, showing a significant cytonuclear discrepancy. Conclusions: We characterized and compared the chloroplast genome features across eight Lithocarpus species, followed by comprehensive phylogenetic analyses. These findings provide critical insights for resolving taxonomic uncertainties and advancing systematic research in this genus. Full article

Ivermectin, an anthelmintic used in livestock, is excreted in faeces and can therefore affect non-target organisms. While its effects on coprophagous insects have been well studied, recent research suggests that it can be taken up by plants, raising the possibility that it may affect a much wider range of invertebrates than previously known. Our study investigated the effects of ivermectin on insects from different feeding guilds. First, we tested its effects on the larvae of the noctuid moths Spodoptera frugiperda and Helicoverpa armigera (chewing herbivores) using an artificial diet. Secondly, we investigated the effects of its presence in the soil of pea plants Pisum sativum on the pea-feeding aphid Acyrthosiphon pisum (phloem-feeding herbivore). Thirdly, we tested ivermectin in an artificial diet for Drosophila melanogaster used as a host for the parasitoid Pachycrepoideus vindemmiae. Our results showed that ivermectin reduced pupal weight and survival in moth larvae, inhibited aphid colony establishment and reduced parasitoid emergence rates from ivermectin-exposed Drosophila pupae. These results highlight the potential of ivermectin to affect multiple trophic levels and emphasise the need for sustainable veterinary practices in the use of anthelmintics in free-ranging livestock and companion animals. Full article

Urbanization replaces natural vegetation for city expansion, impacting environmental and climatic variables that affect the health of the human population and fauna. These changes affect important groups such as birds, given their greater sensitivity to anthropogenic alterations, especially when we understand these effects on a large scale, considering countries such as Brazil, which represents the third country with the greatest diversity of bird species in the world. Conversely, green spaces like urban parks, tree-lined avenues, and riparian forests seem to foster biodiversity conservation. Here, we analyze the effects of vegetation on bird communities and bird–plant interactions in urban riparian areas that have undergone ecological restoration. The study was carried out between January and October 2019 in two restored urban areas of Uberlândia, Brazil. Results showed that the richness of birds observed between the two areas was Praia Clube (n = 86) and Parque Linear Rio Uberabinha (n = 80). The most representative trophic guilds in the areas, with the highest proportion in their relative abundances during both seasons, were granivores, omnivores, insectivores, and frugivores. Composition varied significantly between areas as a function of the plant community, particularly when considering the interaction between season and area (ANOSIM: R = 0.19; Stress = 0.10; p = 0.008). In environments dominated by generalist and synanthropic species (Eared Dove, Picazuro Pigeon), effective planning and management of green areas are crucial. It is important to acknowledge that certain bird species depend on specific habitats, such as riparian forests, and that specific plant species within these areas are vital for specialized bird species, such as species endemic to the Brazilian Savanna or Cerrado and restricted to Brazil (White-striped Warbler) and species in vulnerable categories globally (Bare-faced Curassow). Therefore, restoration efforts in degraded areas should be carefully planned to restore interactions and conserve biodiversity effectively. Full article

Primate species differ drastically from most other mammals in how they visually perceive their environments, which is particularly important for foraging, predator avoidance, and detection of social cues. Background/Objectives: Although it is well established that primates display diversity in color vision and various ecological specializations, it is not understood how visual system characteristics and ecological adaptations may be associated with gene expression levels within the primary visual cortex (V1). Methods: We performed RNA-Seq on V1 tissue samples from 28 individuals, representing 13 species of primates, including hominoids, cercopithecoids, and platyrrhines. We explored trait-dependent differential expression (DE) by contrasting species with differing visual system phenotypes and ecological traits. Results: Between 4–25% of genes were determined to be differentially expressed in primates that varied in type of color vision (trichromatic or polymorphic di/trichromatic), habitat use (arboreal or terrestrial), group size (large or small), and primary diet (frugivorous, folivorous, or omnivorous). Conclusions: Interestingly, our DE analyses revealed that humans and chimpanzees showed the most marked differences between any two species, even though they are only separated by 6–8 million years of independent evolution. These results show a combination of species-specific and trait-dependent differences in the evolution of gene expression in the primate visual cortex. Full article

This study evaluated the effects of gaseous pollutants and vegetation on the structure of fruit-feeding butterfly communities (some subfamilies of Nymphalidae) in a Caatinga area in Brumado, BA, between 2016 and 2018. Two transects were established: Transect “I” (presence of pollutant plumes) and Transect “II” (absence), encompassing a forest fragment and pasture. Bait traps were installed in each transect, and the butterfly communities were analyzed using faunistic indices, including species richness, Shannon diversity index, abundance, and dominance. The canopy opening was also assessed. The composition of fruit-feeding butterfly communities was influenced by both pollutants and vegetation. Gaseous pollutants increased butterfly abundance, diversity, and species richness, though species dominance remained unaffected. Notably, the abundance of Hamadryas februa was particularly sensitive to pollutant exposure. Conversely, increased canopy opening was negatively associated with butterfly abundance and diversity. A relationship between canopy opening and the presence of gaseous pollutants may reflect changes in the abundance and diversity of fruit-feeding butterfly species in the study region. Long-term community monitoring is important, as interannual differences in population fluctuations are common. A better understanding of the patterns found is essential to for devise devising conservation strategies for frugivorous butterfly communities in mining ventures. Full article

Mining is an indispensable activity that threatens biodiversity globally. However, assessments of key ecological processes for the maintenance of plants threatened by mining, such as the effectiveness of frugivory and seed dispersal, are almost non-existent. We evaluated the effectiveness of fruit and seed dispersal in the threatened cactus Browningia candelaris at two different sites: one distant and one close to a mining company currently in operation. Unfortunately, in the study area, B. candelaris is only present in the two evaluated sites, which makes it impossible to have replications for the distant and nearby sites. With this caveat in mind, we evaluated the different parameters of dispersal effectiveness by comparing both sites, far and close to the copper mine. Fruit abundance was significantly higher near the mine. By contrast, animal richness was lower near the mine. However, animal visitation rates for consumption of immature and mature fruits did not differ significantly between sites. Of the 15 animals observed, only four consumed and defecated live seeds: the fox Lycalopex culpaeus, the lizard Microlophus theresioides, and the mouse Octodontomys gliroides and Phyllotis xantopygus. Seed dispersal effectiveness was higher near the mine, but extremely low at both sites. In fact, population recruitment of new cacti was null at both sites, near and far from the mine, due to the scarcity of water in the environment. This is probably due to the increasing aridity of the Atacama Desert due to global warming. Therefore, new studies to assess synergies between potential local threats, such as mining operations, and global threats, such as global warming, are essential to carry out relevant conservation actions on endangered species such as cacti. Full article

In May 2008, Chaitén volcano entered an eruptive process, leading to one of the world’s largest eruptions in recent decades. The magnitude of tephra ejected by the eruption left different types of disturbances and caused diverse forms of environmental damage that were heterogeneously distributed across the surrounding area. We went to the field to assess the early vegetation responses a year after the eruption in September 2009. We evaluated the lateral-blast disturbance zone. We distributed a set of plots in three disturbed sites and one in an undisturbed site. In each of these sites, in a rectangular plot of 1000 m², we marked all standing trees, recording whether they were alive, resprouting, or dead. Additionally, in each site of 80 small plots (~4 m²), we tallied the regenerated plants, their coverage, and the log volume. We described whether the plant regeneration was occurring on a mineral or organic substrate (i.e., ash or leaf litter, respectively). In the blast zone, the eruption created a gradient of disturbance. Close to the crater, we found high levels of devastation marked by no surviving species, scarcely standing-dead trees and logs, and no tree regeneration. At the other extreme end of the disturbance zone, the trees with damaged crowns were resprouting, small plants were regrowing, and seedlings were more dispersed. The main form of regeneration was the resprouting of trunks or buried roots; additionally, a few seedlings were observed in the small plots and elsewhere in disturbed areas. The results suggest that the early stages of succession are shaped by life history traits like dispersion syndrome and regeneration strategy (i.e., vegetative), as was found after other volcanic eruptions. Likewise, the distribution of biological legacies, which is related to disturbance intensity, can cause certain species traits to thrive. For instance, in the blow-down zone, surviving species were chiefly those dispersed by the wind, while in the standing-dead zone, survivors were those dispersed by frugivorous birds. Additionally, we suggest that disturbance intensity variations are related to the elevation gradient. The varying intensities of disturbance further contribute to these ecological dynamics. The early succession in the blast zone of Chaitén volcano is influenced by the interaction between species-specific life history, altitudinal gradient, and biological legacies. Further studies are required to observe the current successional patterns that occur directly in the blast zone and compare these results with those obtained following other volcanic disturbances. Full article

Seed dispersal by frugivorous mammals is crucial for plant reproduction, but anthropogenic disturbances can disrupt this process. However, there is a lack of research on mammalian seed dispersal in anthropogenic habitats, with few systematic literature reviews available. In order to address this gap, a review of scientific literature published since 1990 was conducted. A total of 275 articles from 52 countries, predominantly from South America, were found for the review. These articles contained information on 764 mammal species from 54 families, with Canidae being the most studied. The studies focused on various aspects of seed dispersal, including animal visitation rates (60%), seed quantity in faeces (78.9%), seed viability (49.1%), germination (49.5%), and seedling recruitment. However, only a small percentage of the studies examined the impacts of human disturbance on seed dispersal (5.8%), particularly the quantity of seeds dispersed. There is a need for further studies that integrate the analysis of seed dispersal effectiveness by mammals while considering the effects of human disturbances, particularly in areas with high plant and mammal diversity threatened by human activities. Full article