Bat Abundance Research Articles

Response of phyllostomid bat diversity to tree cover types in North-western Ecuador

Agricultural activities affect tropical forest biodiversity; however, some bat species can survive under these anthropogenic changes. We described the characteristics of phyllostomid bat assemblages in tree covers located in 48 plots among four agricultural landscapes of North-western Ecuador. Bats were captured with mist nets installed at a ground level reaching three meters’ height. For each of the plots, we installed a mist net in four types of tree cover (polyspecific live fences, monospecific live fences, cacao plantations, and isolated trees in pastures). We captured 250 phyllostomid bats belonging to 16 species with a trapping effort of 19,200 m2 of net coverage. Polyspecific live fences showed significant differences in relative abundance, richness, and diversity of phyllostomid bats compared to the other three. Frugivorous and nectarivorous guilds were the most abundant, and also exhibited the highest richness among other guilds present in agricultural landscapes. In addition, frugivorous, and nectarivorous guilds increase their abundance and richness in agricultural landscapes, while the animalivorous guild is negatively affected. We recommend installing polyspecific live fences in tropical production systems to support the conservation of phyllostomid bats. We conclude that living fences composed of various plant species favour the abundance, richness, and diversity of phyllostomid bats.

Long-term monitoring of a population of greater horseshoe bat emphasises the importance of a pest beetle prey on demographic trends.

The global decline in insect biomass has far-reaching implications for terrestrial and freshwater food webs, impacting species reliant on insects as a crucial component of their diet. This issue extends to species traditionally considered agricultural pests, such as the common cockchafer Melolontha melolontha. In the race to combat cockchafers through collection, insecticide use, and other control methods, the repercussions of their numerical fluctuations on predators, including species of high conservation importance like bats, have been largely overlooked. Drawing on 31-years of monitoring data for a greater horseshoe bat Rhinolophus ferrumequinum population in the Aosta Valley (Western Italian Alps), we investigated whether annual fluctuations in bat counts are influenced by cockchafer availability and weather conditions. Despite an overall positive trend in bat abundance, we observed pronounced annual fluctuations, mostly driven by cockchafer availability rather than variations in temperature and precipitation. Furthermore, we found a significant association between cockchafer availability and the median date of birth and birth rate of bats. Births occurred approximately 5 days earlier in cockchafer flight years, with earlier births also linked to warmer spring temperatures and higher numbers of warm days in April. Moreover, the ratio pups/older bats was 0.56 in cockchafer flight years, compared to 0.47 in other years. Our results underscore the importance of considering predator-prey dynamics when examining the long-term population trends of species of conservation concern. We recommend implementing restrictions on the use of chemicals and other potentially harmful practices that may diminish prey abundance or quality, including that of species considered as agricultural pests. In designing conservation strategies, a delicate balance should be struck between the current interests of farmers and the overarching goal of preserving biodiversity against potential future threats.

The role of landscape context in shaping bat assemblages in African cacao plantations

Cacao production is mostly concentrated in Africa, with this continent exporting an impressive 68.4 % of the world's cacao. The increasing demand for cacao from the Global North has already led to massive deforestation in Ghana and Ivory Coast and cacao-driven deforestation is likely to continue changing landscapes in Sub-Saharan Africa. Bats are affected by these landscape changes due to their dependence on multiple resources spread at a large spatial scale. Although bats can save cacao farmers millions of euros through pest suppression, no study has investigated how landscape context affects bat communities in African cacao plantations. Here for the first time, we studied how abundance and richness of insectivorous, frugivorous and nectarivorous bats within cacao landscapes could be affected by cover type and the distance between these habitats and each cacao plantation. We sampled bats using mist-nets in 38 cacao plantations spread throughout southern Cameroon from 2017 to 2020. We found that guilds responded differently to the distance and amount of cover of each of the land cover types, with the scale of response being habitat-dependent. Overall, insectivorous bats were associated positively with high cover of natural habitats (e.g., tree cover, rangeland, and flooded vegetation), and negatively with nearby anthropogenic disturbance (e.g., logging and intensive agriculture). Frugivorous and nectarivorous bats were associated to the presence of natural habitats with water and of nearby anthropogenic habitats (e.g., human settlements, community forests and unpaved roads), probably due to the presence of more fruiting and flowering trees. Considering the associations found between the landscape metrics and bats, we propose three different conceptual designs to manage cacao landscapes: one for insectivores, one for frugivores/nectarivores and a third design that maximises the trade-offs between these three guilds. By safeguarding the diversity of these three guilds farmers can maintain pest suppression services within their plantations and guarantee healthy and long-lasting sustainable cacao landscapes through bats' pollination and seed dispersal.

Fungal and bat diversities along a landscape gradient in central Mexico.

Species interactions between bats and fungi are poorly known. We documented the association between fungal and bat diversities along a landscape gradient. Ten, eight, and seven bat species were captured in conserved, semi-conserved, and urban sites, respectively. Eptesicus fuscus, Myotis ciliolabrum and Corynorhinus townsendii were the most abundant in conserved and semi-conserved sites. E. fuscus, Myotis velifer, and Lasiurus cinereus were abundant in urban sites. C. townsendii was the least abundant bat. A total of 15 cultivated fungi genera included the fungal diversity in bats, of which nine fungi genera were shared along the landscape gradient. Penicillium and Aspergillus were the most abundant genera, and Aureobasidium, Bispora, Stachybotrys, and Verticillium were only documented in the conserved sites. We observed a higher fungal diversity associated with bat species along this landscape gradient. The individual site-based accumulation curves of fungal diversity showed significant decreasing values along the conserved, semi-conserved, and urban sites, respectively. In conserved and urban sites, M. californicus and M. velifer showed the highest fungal diversity, respectively. E. fuscus was associated to the fungi genera Scopulariopsis, Alternaria, Penicillium and Beauveria; L. cinereus to Cladosporium and Aspergillus, and M. velifer to Alternaria sp1, Bispora and Trichoderma. Conserved sites showed both high bat and fungal diversities [species richness and abundance] compared to semi-conserved and urban sites. More studies associating bat and fungal diversities in other ecosystems are needed to corroborate this pattern.

DIVERSITY OF BATS IN HALABAN MONITORING POST AREA, SEI BETUNG, GUNUNG LEUSER NATIONAL PARK

Halaban Monitoring Post, Sei Betung Resort, Gunung Leuser National Park is a rehabilitated forest restoration location since 2017 after previously being diversified from oil palm land. The location has currently become a habitat for various types of animals, including bats. The identification of bat species at the Halaban Monitoring Post is conducted to assess the presence of fauna, with important ecological roles in pollination. Identification was conducted using mist nets installed at five observation points. Our observations showed that 87 individuals of Microchiroptera family bats were found, belonging to 4 species: Cynopterus brachyotis (38 individuals), Cynopterus minutus (15 individuals), Glischropus tylopus (1 individual), Hipposideros cervinus (33 individuals). Further analysis showed Shannon-Wiener diversity index ranges from 0.0 to 0.94 and Margalef species richness index ranges from 0.0 to 0.69. Bat abundance tends to be evenly distributed with an evenness index of 0.0 to 1.35. There is a dominant species at one of the locations with a dominance index value of 0.85.

Summer chiropteran community in the Sergievka Park with the unique dominance of Pipistrellus nathusii on the northern periphery of its distribution range

The study of species on the periphery of their ranges is especially relevant for long-term research in protected areas. The aim of this study is to test the hypothesis that Pipistrellus nathusii on the northern periphery of its range has a clumped distribution with long-term viable breeding centres. The species composition and relative abundance of bats in the park were determined through capturing them with mist nets during the 1997–1998 and 2020–2022 survey periods. Within the 2nd survey period the use of an ultrasonic detector was additionally involved. Stability of the bat species composition in the protected area and a significant difference in the relative abundance between the surveys were revealed (χ2 = 47.31, p < 0.05). During both periods, the bat community in the park exhibited a pronounced dominance of P. nathusii and stable values of its relative abundance (40.7 and 44.2%, respectively). Perennial nursery colonies of Myotis daubentonii, Nyctalus noctula, and P. nathusii have been discovered in the park, which are arguably among the northernmost findings (59.89° N, 29.88° E) in European Russia. The catch rate (6.3 bats per net-night) and acoustic activity of the Chiroptera (16.6 active minutes per detector-hour) on the pond was significantly higher than on the alley and glade. This pattern is typical for all frequently recorded bat species – P. nathusii, N. noctula and Eptesicus nilssonii. According to the results of multiple analysis of variance, the effect of species on acoustic activity was the greatest (η = 24.59%, F = 15.52, p < 0.001). The impact of the habitat and the time since sunset, as well as the pairwise combined impact of these three factors, was also significant and reliable. The sizes of the nursery colonies were determined, which in P. nathusii were record high for the northern periphery of the breeding range, 212 individuals. Evening departures of P. nathusii from the nursery colony on the alley were characterized by their beginning before sunset, and from the nursery colony in the glade after sunset. The intensity of P. nathusii departure from the colony in the forest part of the park is significantly higher (5.3 bats/ min) than in the glade (1.4 bats/min). The fact that large nursery colonies of P. nathusii have existed for decades locally at 60° N latitude suggests the species may have a wider distribution in Eastern Fennoscandia in transformed areas containing old trees. Keywords: bats; South-Eastern Fennoscandia; relative abundance; nursery colonies; acoustic activity; circadian rhythms

The mite Dentocarpus silvai (Acari, chirodiscidae) as a parasite of the bat Molossus molossus (Chiroptera, molossidae) in southeastern Brazil

ABSTRACT Factors that influence the parasite load in a host bat include sex, age, reproductive condition, health, and body condition. Among the ectoparasitic mites found on bats, species from the family Chirodiscidae are commonly observed on molossid bats. This study aimed to analyse the parasitism of Dentocarpus silvai on Molossus molossus in two roosts, discussing the ecology of the host–ectoparasite relationship. We sampled a colony of M. molossus sheltering in the roof lining of a house and in the hollow of a Mangifera indica tree located on Itacuruçá Island, Rio de Janeiro state, southeastern Brazil. A total of 495 D. silvai were collected from 176 M. molossus. Parasitological indices (mean intensity and prevalence) were higher in the tree hollow than in the roof lining, with females being more heavily parasitized than males. Among the six models evaluated, bat abundance best explained the variation in the number of mites. The dispersal success and infestation of D. silvai are associated with roost commuting by individuals (mainly females) of M. molossus that favours the infestation of new bats, which may extend the parasite occurrence. The present study is the first to analyse the infestation of D. silvai on a host species.

Using mobile acoustic monitoring and false‐positive N‐mixture models to estimate bat abundance and population trends

AbstractEstimating the abundance of unmarked animal populations from acoustic data is challenging due to the inability to identify individuals and the need to adjust for observation biases including detectability (false negatives), species misclassification (false positives), and sampling exposure. Acoustic surveys conducted along mobile transects were designed to avoid counting individuals more than once, where raw counts are commonly treated as an index of abundance. More recently, false‐positive abundance models have been developed to estimate abundance while accounting for imperfect detection and misclassification. We adapted these methods to model summertime abundance and trends of three species of bats at multiple spatial scales using acoustic recordings collected along mobile transects by partners of the North American Bat Monitoring Program (NABat) from 2012 to 2020. This multiscale modeling spanned individual transect routes, larger NABat grid cells (10 km × 10 km), and across the entire extent of modeled species ranges. We estimated relationships between species abundances and a suite of abiotic and biotic predictors (landcover types, climatological variables, physiographic diversity, building density, and the impacts of white‐nose syndrome [WNS]) and found varying levels of support between species. We present clear evidence of substantial declines in populations of tricolored bats (Perimyotis subflavus) and little brown bats (Myotis lucifugus), declines that corresponded in space and time with the progression of WNS, a devastating disease of hibernating bats. In contrast, our analysis revealed that similar population‐wide declines probably have not occurred in big brown bats (Eptesicus fuscus), a species known to be less affected by WNS. This study provides the first abundance‐based species distribution predictions and population trends for bats in their summer ranges in North America. These models will probably be applicable to assessing wildlife populations in other monitoring programs where acoustic data are used or where false‐negative and false‐positive detections are present. Finally, our abundance framework (as a spatial point pattern process) can serve as a foundation from which more sophisticated integrated species distribution models that incorporate additional streams of monitoring data (e.g., stationary acoustics, captures) can be developed for North American bats.

Nature-based solutions to increase rice yield: An experimental assessment of the role of birds and bats as agricultural pest suppressors in West Africa

Rice is widely consumed as a staple food, being cultivated worldwide. However, in West Africa, production is not enough to satisfy demand. Rice often suffers intensive damage by herbivorous arthropods that affect quality and quantity of the grain. Birds and bats have been shown to suppress arthropod pests, potentially enhancing rice productivity and food security. However, the degree to which these taxa provide nature-based solutions for mitigating pest-induced rice losses is poorly known, especially in West Africa. Here, we used experimental exclosures to investigate whether birds and bats reduce plant damage and boost rice yield by suppressing arthropod abundance. In a rural area in northern Guinea-Bissau, we established 14 sets of paired control and experimental exclosures parcels, precluding access of birds and bats to rice plants. We then quantified how the absence of birds and bats influenced arthropod communities, plant damage, and rice yield over a full rice production cycle (six months). Arthropod numbers in exclosures (10.1 ± 9.1 ind./plot) were nearly double those in control plots (5.8 ± 3.0 ind./plot), a result mostly due to a lower spider abundance in the controls. The percentage of leaf and grain damage showed no difference between exclosure and control. Using Structural Equation Models, we uncovered that the exclusion of birds and bats boosted arthropod abundance but had only marginal effects on rice damage and no detectable effect on yield. The exclusion of flying vertebrates led to a marked increase in spider abundance, suggesting an effect of mesopredator release, which in turn likely helped maintaining pest abundance low and potentially contributing to the small overall effect on rice damage and yield. Enhancing the abundance of birds and bats is an interesting option to suppress agricultural pests, but our results highlight the need for a better understanding of ecological interactions in agricultural landscapes in West Africa. We stress the need for more research to inform evidence-based policies using nature-based solutions that foster the natural consumption of pests by vertebrates, as a means to improve food security.

Hydroelectric dam impacts shorten and delay the reproductive periods of female leaf-nosed bats in Western Amazonia

Abstract The life cycles of bats are constrained by availability of resources such as food and shelter. Disruptions limiting otherwise naturally regulated access to these resources ultimately affect the fitness of bat populations and may eventually lead to local extinctions. We sampled bats before and after an Amazonian mega-dam water filling and retrieved data on their reproductive phenology, testing if and how sex ratio, seasonal abundance, and reproductive patterns respond to impacts of the newly operating hydroelectric dam. We analyzed data from 3,298 bat captures of 49 species. Females outnumbered males, previously and after the dam implementation, and we observed seasonal variations in the abundance of bats, which was lower after the implementation of the dam for most species. All species had at least 1 reproductive peak of pregnancy and/or lactation beginning at a variable time across seasons. Most species and functional ensembles were reproductively bimodal, with exceptions being the polymodal Artibeus obscurus and unimodal Phylostomus elongatus. Operations of the hydroelectric dam affected the abundance of both sexes equally, and effects were stronger in the rainy season, altering the timing of reproduction for females, delaying and shortening pregnancy and lactation. These changes expressed in female reproductive activity may be related to the shortfall of resources because of loss of irreplaceable vegetation caused by the dam filling. As we cannot predict the roles of variation of reproductive patterns observed after the filling in the long run we reinforce the importance of long-term, continuous monitoring and management to safeguard the reestablishment of reproductive patterns of females in order to repopulate and keep bat populations healthy in remaining areas along following dam construction.

Hibernacula of bats in Mexico, the southernmost records of hibernation in North America.

Although Mexico holds the southernmost hibernating bats in North America, information on winter behavior and hibernacula microclimate use of temperate Mexican bats is limited. We studied hibernating bats at high altitudes (>1,000 m a.s.l.) in northern and central Mexico during 5 consecutive winters. Our aims were to document and describe the hibernacula, winter behavior (such as abundance and roost pattern), and microclimates (estimated as adjacent substrate temperature) of cave-hibernating bats in Mexico. We found 78 hibernacula and 6,089 torpid bats of 10 vespertilionid species, increasing by over 50% the number of cave-hibernating bat species and quadrupling the number of hibernacula for Mexico. Hibernacula were at altitudes between 1,049 and 3,633 m a.s.l., located in 3 mountain ranges, mainly in oak and conifer forests. Myotis velifer was the most common species, followed by Corynorhinus townsendii and C. mexicanus. We recorded the adjacent substrate temperatures from 9 species totaling 1,106 torpid bats and found differences in microclimate use among the 3 most common species. In general, abundance of torpid bats in our region of study was similar to those in the western United States, with aggregations of tens to a few hundred individuals per cave, and was lower than in the eastern United States where a cave may hold thousands of individuals. Knowledge of bat hibernation is crucial for developing conservation and management strategies on current conditions while accommodating environmental changes and other threats such as emerging diseases.

White-nose syndrome, winter duration, and pre-hibernation climate impact abundance of reproductive female bats.

White-nose syndrome (WNS) is an infectious disease that disrupts hibernation in bats, leading to premature exhaustion of fat stores. Though we know WNS does impact reproduction in hibernating female bats, we are unsure how these impacts are exacerbated by local climate factors. We compiled data from four southeastern U.S. states and used generalized linear mixed effects models to compare effects of WNS, pre-hibernation climate variables, and winter duration on the number of reproductive females in species across the range of WNS susceptibility. We predicted we would see a decline in the number of reproductive females in WNS-susceptible species, with the effect exaggerated by longer winter durations and pre-hibernation climate variables that lead to reductions in foraging. We found that the number of reproductive females in WNS-susceptible species was positively correlated with pre-hibernation local climate conditions conducive to foraging; however, WNS-susceptible species experienced an overall decline with the presence of WNS and as winter duration increased. Our long-term dataset provides evidence that pre-hibernation climate, specifically favorable summer weather conditions for foraging, greatly influences the reproduction, regardless of WNS status.

Bat diversity boosts ecosystem services: Evidence from pine processionary moth predation

Coniferous forests contribute to the European economy; however, they have experienced a decline since the late 1990s due to an invasive pest known as the pine processionary moth, Thaumetopoea pityocampa. The impacts of this pest are increasingly exacerbated by climate change. Traditional control strategies involving pesticides have had negative effects on public health and the environment. Instead, forest managers seek a more ecological and sustainable approach to management that promotes the natural actions of pest control agents. This study aims to evaluate the role of bats in suppressing pine processionary moths in pine forests and examine how the bat community composition and abundance influence pest consumption. Bats were sampled in the mountainous environment of the Serra da Estrela in central Portugal to collect faecal samples for DNA meta-barcoding analysis. We assessed the relationship between a) bat richness, b) bat relative abundance, c) bat diet richness, and the frequency of pine processionary moth consumption. Our findings indicate that sites with the highest bat species richness and abundance exhibit the highest levels of pine processionary moth consumption. The intensity of pine processionary moth consumption is independent of insect diversity within the site. The highest occurrence of pine processionary moth presence in bat diets is primarily observed in species that forage in cluttered habitats. A typical predator of pine processionary moths among bats is likely to be a forest-dwelling species that specialises in consuming Lepidoptera. These species primarily use short-range echolocation calls, which are relatively inaudible to tympanate moths, suitable for locating prey in cluttered environments, employing a gleaning hunting strategy. Examples include species from the genera Plecotus, Myotis, and Rhinolophus. This study enhances our understanding of the potential pest consumption services provided by bats in pine forests. The insights gained from this research can inform integrated pest management practices in forestry.

Bats of the Tunisian Desert: Preliminary Data Using Acoustic Identification and First Record of Taphozous nudiventris in the Country

Increasing aridity usually results in decreasing bat abundance and species richness, and the Saharan desert is an example of such impoverishment. Moreover, the harsh climatic and field conditions in this area restrict the feasibility of surveys. Therefore, the bat fauna of the Tunisian Sahara was unstudied until an expedition was conducted in May 2021. A total of seven species were recorded using passive bat detectors set mainly at water bodies, which concentrate bat activity. Echolocation calls of these species did not depart from published records for the Mediterranean area. Our data failed to identify the two ecomorphotypes of Pipistrellus kuhlii but confirmed the adaptability of this species to local conditions. For the first time in Tunisia, we recorded echolocation calls of Taphozous nudiventris, a species that has been rarely reported in North Africa. The highest species richness was identified at the largest wetlands of Oued Daghsen (Oued Dkouk Nature Reserve) and at Bordj el Khadra (only six and four species, respectively). Most Mediterranean species were recorded in the northern locality, while desert species were more active in the most southern one. The importance of water bodies for bats was confirmed once more. No sign of competition among species was detected, as the Mediterranean and desert-dwelling bat species were active at the same time. Additional surveys should be planned in order to enlarge the list of seven species recorded in only one week.

Do Bats Avoid the Urban Core in the Breeding Season? A Case Study from Temperate Latitudes

Seasonal utilization of urban areas by bats remains inadequately explored. This study aimed to comprehensively survey the species composition and population dynamics of bats during both the breeding season (May–July) and autumn migration season (August–September) within a large urban area, specifically Kharkiv city, Ukraine. We conducted multiyear data collection from 2014 to 2016, employing a combination of acoustic recordings, mist-netting, and registration of opportunistically found bats. The results revealed the identification of seven bat species using all methods (Eptesicus serotinus, Nyctalus noctula, N. leisleri, Pipistrellus pygmaeus, P. kuhlii, P. nathusii, and Vespertilio murinus), with notable differences in species composition between the studied periods. During the migration season, N. noctula was a numerically predominant species, while P. kuhlii and E. serotinus were the most abundant during the breeding season. The urban core bat population during the breeding season primarily consisted of males and solitary reproductive females, mainly represented by P. kuhlii and E. serotinus. Acoustic recording data indicated that N. noctula actively avoided the urban core during the breeding season, but was more common on the city periphery. In contrast, during the migration season, the city experienced a significant surge in bat abundance, both in general and specifically among noctule bats, with their numbers increasing tenfold compared to the breeding season. Moreover, a considerable number of young individuals were observed during the migration season. These findings provide evidence that bats tend to avoid the urban core in large cities at temperate latitudes during the breeding season but actively utilize urban areas during autumn migration. Understanding the seasonal preferences and movements of bats in urban environments is crucial for effective conservation and management strategies.

Seasonal variation and host sex affect bat-bat fly interaction networks in the Amazonian savannahs.

Bats are the second-most diverse group of mammals in the world, and bat flies are their main parasites. However, significant knowledge gaps remain regarding these antagonistic interactions, especially since diverse factors such as seasonality and host sex can affect their network structures. Here, we explore the influence of such factors by comparing species richness and composition of bat flies on host bats, as well as specialization and modularity of bat-bat fly interaction networks between seasons and adult host sexes. We captured bats and collected their ectoparasitic flies at 10 sampling sites in the savannahs of Amapá State, northeastern region of the Brazilian Amazon. Despite female bats being more parasitized and recording greater bat fly species richness in the wet season, neither relationship was statistically significant. The pooled network could be divided into 15 compartments with 54 links, and all subnetworks comprised >12 compartments. The total number of links ranged from 27 to 48 (for the dry and wet seasons, respectively), and female and male subnetworks had 44 and 41 links, respectively. Connectance values were very low for the pooled network and for all subnetworks. Our results revealed higher bat fly species richness and abundance in the wet season, whereas specialization and modularity were higher in the dry season. Moreover, the subnetwork for female bats displayed higher specialization and modularity than the male subnetwork. Therefore, both seasonality and host sex contribute in different ways to bat-bat fly network structure. Future studies should consider these factors when evaluating bat-bat fly interaction networks.

Not all farms are created equal: Shady African cocoa farms promote a richer bat fauna

Bats provide important pest suppression services with economic value to cocoa farmers, yet the impact of cocoa farm management on bat diversity metrics is still poorly understood. This is especially important if we consider that Afrotropical cocoa farms supply 68 % of the world's chocolate market, with expected increases in production in the forthcoming decades. In this study, we investigated for the first time how bat abundance, richness and diversity varied between African cocoa farms with different levels of shade tree cover, shade tree communities and cocoa characteristics. We found that shade tree cover and shade tree height were the main drivers associated with an increase of Shannon diversity, and abundance and richness of insectivores. Frugivorous and nectarivorous bats were positively associated with the presence of planted shade trees, but richness varied with the size of shade trees. The insectivorous Hipposideros fuliginosus was only present in high shade farms, being captured 51 times only in this shade system, while the frugivorous Myonycteris angolensis was associated with low shade farms. Our findings show that indeed not all farms are created equal, with high shade farms with large, tall forest shade trees (i.e., containing key plant resources) having richer bat communities. Therefore, policymakers seeking to conserve wildlife within cocoa farming systems should adopt cocoa management systems like those mentioned above and promote a combination of forest and planted shade trees to be able support a rich community of insectivorous, frugivorous and nectarivorous bats and maintain their associated ecosystems services.

An integrative approach to understanding diversity patterns and assemblage rules in Neotropical bats

Understanding the mechanisms shaping species composition of assemblages is critical for incorporating ecological and evolutionary perspectives into biodiversity conservation. Thus, we quantified the relative support of community assembly mechanisms by assessing how species richness relates to the functional and phylogenetic biodiversity of Neotropical bat assemblages. We assessed the association of functional diversity for functional categories and phylogenetic diversity with species richness for 20 assemblages of Neotropical bats. In addition, we contrasted functional and phylogenetic diversity against null models to determine the mechanisms that structure the assemblages. We hypothesize functional/phylogenetic overdispersion for high species sites and a positive relationship between those dimensions of diversity and richness. Functional divergence increased with species richness, indicating that the variability in ecological attributes among abundant bats increases as the assemblages contain more species. Taxa were more distantly related as richness increases, but distances among closely related species remained constant. We found a consistent tendency of clustering of functional traits in site assemblages, particularly in abundant species. We proposed competition between clades as a possible mechanism modulating the community structure in Neotropical bat assemblages. Our results suggest that decreasing overlap in functional traits between abundant species could promote coexistence with rare species that can buffer ecosystem function due to species loss.

Does size matter? Bat diversity and the use of rock shelters in Brazil

A positive correlation between cave size and bat diversity has been recorded by some authors for different cave areas in South America. We analyzed published and otherwise available data from three Brazilian karst areas and phytogeography domains, including NE and SE Atlantic Forest and Cerrado (savannah-like vegetation), encompassing a wide range of cave sizes. We found no such correlation, as expected in view of previous observations by researchers and speleologists. We discuss the ecological implications of different ways to measure bat diversity, i.e. the accumulative number of species (sequential use of caves) vs. the number of species at a given occasion (species in actual cohabitation) vs. bat abundance (numbers of individuals), as well as speleological topics related to the concept of caves (based on an anthropomorphic definition, not applicable to other species), the problems of estimating topographic variables such as cave area and volume, and the value of including cave temperatures in the analyses. Multiple interacting variables may influence the composition of cave bat communities and bat species richness and abundance. The most important ones would be the density of caves in a given area (related to lithology – calcareous vs. siliciclastic caves), regional climates, and degree of preservation of epigean habitat. Cave morphology, number and size of entrances, and presence of water bodies, as well as interactions with other species, must also be considered. In conclusion, as a general statement for tropical and subtropical bats, cave size (in the human sense) by itself does not matter, except perhaps for one-off situations. Finally, a brief overview of the diversity of cave bats in Brazil is presented.

Bats (Mammalia: Chiroptera) in urban-rural interfaces: community structure associated with pathogen screening in São Paulo-the largest metropolitan region in Brazil.

Little is known about the influence of the urban environments on bat species 'ecology. The urbanization process potentially lead to critical ecological changes in bat communities' intra and interspecific pathogenic transmissions dynamics. To date, the monitoring of pathogens in bats in Brazil has only been done with bats found dead or alive in households, from rabies surveillance systems. The present work aimed to investigate how urbanization influenced bat richness, relative abundance and pathogen occurrence. Most captured bats were Phyllostomidae, especially Sturnira lilium, Artibeus lituratus, A. fimbriatus, Glossophaga soricina, and Platyrrhinus lineatus, among others. From preserved-rural towards urban areas the lesser the bat richness, the higher the relative abundance of the captured bats. Noise level, luminosity and relative humidity correlated with bat abundance. The proportion of genders, sexually active bats and their size (weight, right forearm length, and body condition index) were stable throughout the investigation. Still, the proportion of pregnant females was higher in Spring and the number of juveniles in Summer, evidencing the seasonality of reproduction. Several Enterobacteria were isolated, evidencing a significant role of bats in the circulation of pathogens of medical and veterinary interest. These results are crucial in the pursuit of a harmonious coexistence between humans, bats and domestic animals in areas with different levels of anthropization.