Silvopastoral and conventional management of extensive livestock and the diversity of bats in fragments of tropical dry forest in Córdoba, Colombia

The establishment of extensive livestock systems in the Colombian Caribbean Region has historically generated a strong loss of the tropical dry forest (TDF) with negative effects on biodiversity. Currently, the implementation of silvopastoral systems (SPS) has been proposed with strategy to curb the loss of biodiversity caused by the conventional management system (CS). The objective was to evaluate the effect of SPS and CS of extensive livestock on the assemblage of bats associated with fragments of TDF. During a continuous year and a sampling effort of 30,240 h-net/night, the structure and composition of bat assemblage between SPS and CS were compared. 2788 bats belonging to six families, 23 genera, and 39 species were captured. The Phyllostomidae family presented the highest species richness (S = 30), with the greatest abundance in the Stenodermatinae subfamily (n = 1543). Bat assemblage in the SPS fragments was more equitable; and the relative abundance per species, per genera, and per foraging guilds was also significantly higher. The capture success showed significant variations between the climatic seasons (dry and rainy). The rate of species turnover was higher in the CS fragments. The species Artibeus planirostris, Artibeus lituratus, Carollia perspicillata, Carollia castanea, Phyllostomus discolor, Dermanura phaeotis, Uroderma convexum, Glossophaga soricina, C. brevicauda, and Sturnira lilium accounted for 92% of the captures. In conclusion, frugivorous bats were more abundant in the SPS, type of extensive livestock management that can generate greater temporal stability of bat assemblage. This research provides the first scientific evidence of the positive effect of silvopastoral management on the diversity of bats in tropical dry forest areas of the Colombian Caribbean region.

Inter- and intraspecific variation in the Artibeus species complex demonstrates size and shape partitioning among species

Neotropical leaf-nosed bats (family Phyllostomidae) are one of the most diverse mammalian families and Artibeus spp. is one of the most speciose phyllostomid genera. In spite of their species diversity, previous work on Artibeus crania using linear morphometrics has uncovered limited interspecific variation. This dearth of shape variation suggests that differences in cranial morphology are not contributing to niche partitioning across species, many of which are often found in sympatry. Using two-dimensional geometric morphometric methods on crania from eleven species from the Artibeus species complex, the current study demonstrates substantial cranial interspecific variation, sexual size and shape dimorphism, and intraspecific geographic variation. The majority of species were shown to have a unique size and shape, which suggests that each species may be taking advantage of slightly different ecological resources. Further, both sexual size and shape dimorphism were significant in the Artibeus species complex. Male and female Artibeus are known to have sex specific foraging strategies, with males eating near their roosts and females feeding further from their roosts. The presence of cranial sexual dimorphism in the Artibeus species complex, combined with previous work showing that different fruit size and hardness is correlated with different cranial shapes in phyllostomids, indicates that the males and females may be utilizing different food resources, leading to divergent cranial morphotypes. Additional field studies will be required to confirm this emergent hypothesis. Finally, significant geographical shape variation was found in a large intraspecific sample of Artibeus lituratus crania. However, this variation was not correlated with latitude and instead may be linked to local environmental factors. Additional work on ecology and behavior in the Artibeus species complex underlying the morphological variation uncovered in this study will allow for a better understanding of how the group has reached its present diversity.

DNA barcoding of bats (Chiroptera) from the Colombian northern region

Bats are mammals of great ecological and medical importance, which have associations with different pathogenic microorganisms. DNA barcoding is a tool that can expedite species identification using short DNA sequences. In this study, we assess the DNA barcoding methodology in bats from the Colombian Northern region, specifically in the Córdoba department. Cytochrome oxidase subunit I (COI) gene sequences of nine bat species were typified, and their comparison with other Neotropic samples revealed that this marker is suitable for individual species identification, with ranges of intra-species variation from 0.1 to 0.9%. Bat species clusters are well supported and differentiated, showing average genetic distances ranging from 3% between Artibeus lituratus and Artibeus planirostris, up to 27% between Carollia castanea and Molossus molossus. C. castanea and Glossophaga soricina show geographical structuring in the Neotropic. The findings reported in this study confirm DNA barcoding usefulness for fast species identification of bats in the region.

Using Data Mining and Network Analysis to Infer Arboviral Dynamics: The Case of Mosquito-Borne Flaviviruses Reported in Mexico

Given the significant impact of mosquito-borne flaviviruses (MBFVs) on both human and animal health, predicting their dynamics and understanding their transmission cycle is of the utmost importance. Usually, predictions about the distribution of priority pathogens, such as Dengue, Yellow fever, West Nile Virus and St. Louis encephalitis, relate abiotic elements to simple biotic components, such as a single causal agent. Furthermore, focusing on single pathogens neglects the possibility of interactions and the existence of common elements in the transmission cycles of multiple pathogens. A necessary, but not sufficient, condition that a mosquito be a vector of a MBFV is that it co-occurs with hosts of the pathogen. We therefore use a recently developed modeling framework, based on co-occurrence data, to infer potential biotic interactions between those mosquito and mammal species which have previously been identified as vectors or confirmed positives of at least one of the considered MBFVs. We thus create models for predicting the relative importance of mosquito species as potential vectors for each pathogen, and also for all pathogens together, using the known vectors to validate the models. We infer that various mosquito species are likely to be significant vectors, even though they have not currently been identified as such, and are likely to harbor multiple pathogens, again validating the predictions with known results. Besides the above “niche-based” viewpoint we also consider an assemblage-based analysis, wherein we use a community-identification algorithm to identify those mosquito and/or mammal species that form assemblages by dint of their significant degree of co-occurrence. The most cohesive assemblage includes important primary vectors, such as A. aegypti, A. albopictus, C. quinquefasciatus, C. pipiens and mammals with abundant populations that are well-adapted to human environments, such as the white-tailed deer (Odocoileus virginianus), peccary (Tayassu pecari), opossum (Didelphis marsupialis) and bats (Artibeus lituratus and Sturnira lilium). Our results suggest that this assemblage has an important role in the transmission dynamics of this viral group viewed as a complex multi-pathogen-vector-host system. By including biotic risk factors our approach also modifies the geographical risk profiles of the spatial distribution of MBFVs in Mexico relative to a consideration of only abiotic niche variables.

Frugivorous bat (Chiroptera: Phyllostomidae) community structure and trophic relations in Atlantic Forest fragments

We evaluated the structure of a community of frugivorous bats using composition and abundance patterns, niche amplitude and food overlap of these animals in four Atlantic Forest fragments, each one exposed to different conservation realities. For twelve months, we captured six bat species and found the seeds of 13 species of pioneering plants in 158 fecal samples. The most abundant bat species were Artibeus planirostris (25.4%), Artibeus lituratus (24.1%) and Carollia perspicillata (23.9%). Only one fragment (Fazenda Unida), the most conserved area, exhibited a significantly different composition and abundance of species. We found low trophic niche amplitude values (<0.60), associated to high food overlaps. Our results suggest that bats can adjust their foraging strategy to deal with food availability variations. By favoring pioneering plant species, the fragmentation process noted of the studied areas creates an attractive environment for bats more tolerant to this type of disturbance. The sampled areas represent important secondary forest remnants in southern Brazil that require attention to avoid an even greater loss of bat diversity.

Bat species composition associated with restinga lagoons from the Paulo César Vinha State Park, Espírito Santo, Brazil

Restingas are coastal ecosystems associated with the Atlantic Forest. They are threatened by habitat degradation and forest fragmentation due to intense human occupation. Many restingas have coastal lagoons formed by bay sedimentation of bays, the presence of river estuaries, or emerging groundwater. The distance between lagoons and the ocean influences the biotic community in them. This study aimed to compare the diversity (composition, abundance and richness) of bat communities associated with three lagoons within the Paulo Cesar Vinha State Park, Espírito Santo state. Two lagoons (‘Feia’ and ‘Vermelha’ lagoons) are 2 km away from the ocean, while the third (‘Caraís’ lagoon) is just a few meters distant from the ocean. Species composition did not differ among the lagoons. Abundance of Carollia perspicillata and Glossophaga soricina was higher in the ‘Caraís’ lagoon. Abundance of Artibeus lituratus and Platyrrhinus lineatus was higher in the ‘Vermelha’ lagoon. Species with higher abundance in the ‘Vermelha’ are usually associated with urban and disturbed environments. ‘Vermelha’ lagoon is closer to human settlements and this could be a major driver of bat species abundance associated with this lagoon instead of distance from the ocean. These results may be used to guide conservations efforts in the restingas or habitats associated with restingas.

DIVERSIDAD DE MURCIÉLAGOS EN EL INTERFLUVIO NAPO-PUTUMAYO-AMAZONAS, PERÚ

Los murciélagos son uno de los grupos más diversos de mamíferos en el neotrópico y sus funciones como bioindicadores resaltan su importancia. Es así, que tuvimos el interés de conocer su diversidad, estado de conservación y amenazas en el interfluvio Napo-Putumayo-Amazonas, un sector aún poco explorado de la Amazonía peruana. Para ello sistematizamos estudios de diversas fuentes de información. Encontramos 53 especies de murciélagos, siendo la familia Phyllostomidae y sub familia Stenodermatinae los más representativos. Las especies Artibeus lituratus, Artibeus obscurus, Lophostoma silvicolum, Phyllostomus elongatus, Rhynchonycteris naso y Sturnira tildae se registraron ampliamente en el Putumayo. Los murciélagos frugívoros e insectívoros fueron más diversos que otros grupos de hábitos alimentarios. Se registra a Diclidurus ingens como especie única, en tanto Sturnira ludovici, Artibeus concolor, Cynomops greenhalli, Molossops neglectus y Platyrrhinus angustirostris como especies raras en el área de evaluación. La composición de murciélagos indica en buen estado de conservación, sin embargo, podría verse afectado por las crecientes actividades ilícitas de deforestación. Se requiere la pronta implementación de proyectos compatibles con las potencialidades del área, que garanticen la conservación de estos bosques que son fuente de vida para muchas especies de murciélagos y otras especies de fauna silvestre.

Differences in body mass among the frugivorous bats Artibeus lituratus and Carollia perspicillata (Chiroptera: Phyllostomidae) from an urban and a peri-urban area of Cúcuta, Colombia

We report differences in body mass of two species of fruit bats, Artibeus lituratus and Carollia perspicillata, from two fragments of tropical dry forest (TDF) located in urban and peri-urban areas of the city of Cúcuta, Colombia. From January to September 2018 bat sampling was carried out using mist nets to captured and weigh individuals in the field. The analysis was based only on adults who were not in a reproductive state. We found that both males and females of each species had a higher body mass in the peri-urban area than in the urban area. This highlights the importance of testing subsequent hypotheses to explain the body mass variations reported in this note in response to effects related to diet, diseases, and changes in land use, among others.