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.

Conservation gaps for Brazilian bats, limited protection across conservation units and the importance of the indigenous lands.

In Brazil, there is 13% of the world's bat diversity, is the second most diverse group of mammals, playing a crucial role in providing ecosystem services that benefit humans. However, anthropogenic disturbances exacerbate processes of species extinction, shifts in geographic distributions, and phenological changes, despite efforts to safeguard biodiversity through the creation of Conservation Units and Indigenous Lands. Moreover, gaps in taxonomic knowledge and challenges related to species distribution hinder the effective implementation of conservation strategies in protected areas. This study assesses the contribution of Brazilian Conservation Units (both Full Protection and Sustainable Use) and Indigenous Lands to the conservation of bat species and their ecosystem services. It also presents maps illustrating species richness by trophic guilds and threat classification according to IUCN, including species listed as Data Deficient. The findings reveal low percentages of potential bat distribution areas within these protected regions, especially for insectivorous, nectarivorous, and frugivorous bats in the Cerrado biome, which are classified as Near Threatened. Additionally, the highest bat species richness was observed in the Amazon and Atlantic Forest biomes.

Feeding efficiency of two coexisting nectarivorous bat species (Phyllostomidae: Glossophaginae) at flowers of two key-resource plants.

Animals should maximize their energy uptake while reducing the costs for foraging. For flower-visitors these costs and benefits are rather straight forward as the energy uptake equals the caloric content of the consumed nectar while the costs equal the handling time at the flower. Due to their energetically demanding lifestyle, flower-visiting bats face particularly harsh energetic conditions and thus need to optimize their foraging behavior at the flowers of the different plant species they encounter within their habitat. In flight cage experiments we examined the nectar-drinking behavior (i.e. hovering duration, nectar uptake, and the resulting feeding efficiency) of the specialized nectar-feeding bat Hylonycteris underwoodi and the more generalistic Glossophaga commissarisi at flowers of two plant species that constitute important nectar resources in the Caribbean lowland rainforests of Costa Rica and compared nectar-drinking behavior between both bat species and at both plant species. We hypothesized that the 1) specialized bat should outperform the more generalistic species and that 2) bats should generally perform better at flowers of the nectar-rich flowers of the bromeliad Werauhia gladioliflora than at the relatively nectar-poor flowers of the Solanaceae Merinthopodium neuranthum that has an extremely long flowering phase and therefore is an extremely reliable nectar resource, particularly for the specialized Hylonycteris. While we did not find substantial differences in the feeding efficiency of the generalist G. commissarisi, we observed an increased feeding efficiency of the specialized H. underwoodi at flowers of the nectar-poor M. neuranthum. This suggests that familiarity and ecological importance are more important determinants of the interaction than just morphological traits. Our results demonstrate that in addition to morphology, behavioral adaptations are also important drivers that determine the fitness of nectar-feeding bats. Both familiarity with and the ecological importance of a resource seem to contribute to shaping the interactions between pollinating bats and their plants.

Calling to the collective: contact calling rates within groups of disc-winged bats do not vary by kinship or association.

Many group-living animals coordinate social behaviours using contact calls, which can be produced for all group members or targeted at specific individuals. In the disc-winged bat, Thyroptera tricolor, group members use 'inquiry' and 'response' calls to coordinate daily movements into new roosts (furled leaves). Rates of both calls show consistent among-individual variation, but causes of within-individual variation remain unknown. Here, we tested whether disc-winged bats produce more contact calls towards group members with higher kinship or association. In 446 experimental trials, we recorded 139 random within-group pairs of one flying bat (producing inquiry calls for roost searching) and one roosting bat (producing response calls for roost advertising). Using generalized linear mixed-effect models (GLMM), we assessed how response and inquiry calling rates varied by sender, receiver, genetic kinship and co-roosting association rate. Calling rates varied consistently across senders but not by receiver. Response calling was influenced by inquiry calling rates, but neither calling rate was higher when the interacting pair had higher kinship or association. Rather than dyadic calling rates indicating within-group relationships, our findings are consistent with the hypothesis that bats produce contact calls to maintain contact with any or all individuals within a group while collectively searching for a new roost site. This article is part of the theme issue 'The power of sound: unravelling how acoustic communication shapes group dynamics'.

Combined effects of ambient temperature and food availability on induced innate immune response of a fruit-eating bat (Carollia perspicillata).

Resilience of mammals to anthropogenic climate and land-use changes is associated with the maintenance of adequate responses of several fitness-related traits such as those related to immune functions. Isolated and combined effects of decreased food availability and increased ambient temperature can lead to immunosuppression and greater susceptibility to disease. Our study tested the general hypothesis that decreased food availability, increased ambient temperature and the combined effect of both factors would affect selected physiological and behavioral components associated with the innate immune system of fruit-eating bats (Carollia perspicillata). Physiological (fever, leukocytosis and neutrophil/lymphocyte ratio) and behavioral (food intake) components of the acute phase response, as well as bacterial killing ability of the plasma were assessed after immune challenge with lipopolysaccharide (LPS: 10 mg/kg) in experimental groups kept at different short-term conditions of food availability (ad libitum diet or 50% food-deprived) and ambient temperature (27 and 33°C). Our results indicate that magnitude of increase in body temperature was not affected by food availability, ambient temperature or the interaction of both factors, but the time to reach the highest increase took longer in LPS-injected bats that were kept under food restriction. The magnitude of increased neutrophil/lymphocyte ratio was affected by the interaction between food availability and ambient temperature, but food intake, total white blood cell count and bacterial killing ability were not affected by any factor or interaction. Overall, our results suggest that bacterial killing ability and most components of acute phase response examined are not affected by short-term changes in food availability and ambient temperature within the range evaluated in this study, and that the increase of the neutrophil/lymphocyte ratio when bats are exposed to low food availability and high ambient temperature might represent an enhancement of cellular response to deal with infection.

Spatial clusters, temporal behavior, and risk factors analysis of rabies in livestock in Ecuador.

Rabies, a globally distributed and highly lethal zoonotic neglected tropical disease, has a significant impact in South America. In Ecuador, animal rabies cases are primarily linked to livestock, and hematophagous bats play a crucial role in disease transmission. This study aims to identify temporal trends, spatial patterns, and risk factors for animal rabies in Ecuador between 2014 and 2019. Epidemiological survey reports from the official Animal Rabies Surveillance Program of the Phyto and Zoosanitary Regulation and Control Agency of Ecuador (AGROCALIDAD) were used. The Animal Rabies Surveillance Program from AGROCALIDAD consists of an official passive surveillance program that receives reports from farmers or individuals (both trained or untrained) who have observed animals with neurological clinical signs and lesions compatible with bat bites, or who have seen or captured bats on their farms or houses. Once this report is made, AGROCALIDAD personnel is sent for field inspection, having to confirm the suspicion of rabies based on farm conditions and compatibility of signs. AGROCALIDAD personnel collect samples from all suspicious animals, which are further processed and analyzed using the Direct Fluorescent Antibody (DFA) test for rabies confirmatory diagnosis. In this case, study data comprised 846 bovine farms (with intra-farm sample sizes ranging from 1 to 16 samples) located in different ecoregions of Ecuador; out of these, 397 (46.93%) farms tested positive for animal rabies, revealing six statistically significant spatial clusters. Among these clusters, three high-risk areas were identified in the southeast of Ecuador. Seasonality was confirmed by the Ljung-Box test for both the number of cases (p < 0.001) and the positivity rate (p < 0.001). The Pacific Coastal lowlands and Sierra regions showed a lower risk of positivity compared to Amazonia (OR = 0.529; 95% CI = 0.318 - 0.883; p = 0.015 and OR = 0.633; 95% CI = 0.410 - 0.977; p = 0.039, respectively). The breeding of non-bovine animal species demonstrated a lower risk of positivity to animal rabies when compared to bovine (OR = 0.145; 95% CI = 0.062 - 0.339; p < 0.001). Similarly, older animals exhibited a lower risk (OR = 0.974; 95% CI = 0.967 - 0.981; p < 0.001). Rainfall during the rainy season was also found to decrease the risk of positivity to animal rabies (OR = 0.996; 95% CI = 0.995 - 0.998; p < 0.001). This study underscores the significance of strengthening the national surveillance program for the prevention and control of animal rabies in Ecuador and other countries facing similar epidemiological, social, and geographical circumstances.

Palaeoatmosphere facilitates a gliding transition to powered flight in the Eocene bat, Onychonycteris finneyi.

The evolutionary transition to powered flight remains controversial in bats, the only flying mammals. We applied aerodynamic modeling to reconstruct flight in the oldest complete fossil bat, the archaic Onychonycteris finneyi from the early Eocene of North America. Results indicate that Onychonycteris was capable of both gliding and powered flight either in a standard normodense aerial medium or in the hyperdense atmosphere that we estimate for the Eocene from two independent palaeogeochemical proxies. Aerodynamic continuity across a morphological gradient is further demonstrated by modeled intermediate forms with increasing aspect ratio (AR) produced by digital elongation based on chiropteran developmental data. Here a gliding performance gradient emerged of decreasing sink rate with increasing AR that eventually allowed applying available muscle power to achieve level flight using flapping, which is greatly facilitated in hyperdense air. This gradient strongly supports a gliding (trees-down) transition to powered flight in bats.

Oxidative Stress and Antioxidant Defense in the Heart, Liver, and Kidney of Bat Species with Different Feeding Habits.

The aim of this study was to compare the oxidative metabolism of four neotropical bat species with different feeding habits and investigate the relationship between their feeding habits and oxidative status. In terms of oxidative damage, our findings revealed major differences among the four bat species. In particular, hematophagous bats had lower levels of oxidative damage in the heart but higher levels in the liver. Nectarivorous bats had lower levels of carbonyl groups in the kidneys compared to insectivorous and hematophagous bats. The activity of various antioxidant and non-antioxidant enzymes in the heart, liver, and kidney also showed significant differences among the bat species. H2O2 consumption was lower in the heart of hematophagous bats, while insectivorous bats exhibited the highest enzymatic activity in the kidney. SOD activity was lower in the heart of hematophagous bats and lower in nectarivorous bats in the liver. Fumarase activity was higher in the heart of frugivorous/insectivorous and lower in nectarivorous/hematophagous bats. GPx activity was higher in the heart of nectarivorous/insectivorous and higher in the kidney of insectivorous bats. GST activity was higher in the heart of nectarivorous and lower in hematophagous bats. The correlation analysis between oxidative markers and enzymatic/non-enzymatic antioxidants in the heart, liver, and kidney exhibited distinct patterns of correlations due to variations in antioxidant defense mechanisms and oxidative stress responses in different organs. The observed differences in oxidative damage, antioxidant enzyme activities, and correlations between oxidative markers and antioxidants highlight the adaptability and complexity of the antioxidant defense systems in these bats. Each organ appears to have specific demands and adaptations to cope with oxidative stress based on its physiological functions and exposure to dietary components. Our results have major significance for the conservation and management of bats, which are threatened species despite being crucial components of ecosystems. Our study's implications go beyond bat biology and offer valuable insights into comparative oxidative physiology.

A negative association between nectar standing crop and pollen transfer suggests nectar functions as a manipulator of pollinating bats.

BACKGROUND AND AIMS: Nectar standing crop has a fundamental role in controlling pollinator movements between flowers and individuals within a population. In bat pollination systems, plants take advantage of the cognitive abilities of nectarivorous bats, which integrate complex perceptions of the quality and spatial distribution of resources. Here, we propose that associations between standing crop and pollen transfer help to reveal the role of nectar as a manipulator of pollinator behaviour. METHODS: We used Harpochilus neesianus Ness (Acanthaceae), a bat-pollinated shrub from the Brazilian Caatinga, as a model system to assess nectar removal effects and standing crop, respectively, over the night and to test associations between the amount of nectar available to pollinators, and pollen import and export. KEY RESULTS: Harpochilus neesianus showed continuous nectar secretion throughout the flower lifespan. Flowers subjected to successive nectar removals produced less nectar than flowers sampled just once, and showed, despite a higher sugar concentration, a lower absolute amount of sugar. Under these conditions, bats may realize that nectar production is decreasing after repeated visits to the same flower and could be manipulated to avoid such already pollinated flowers with little nectar, thus increasing the probability of visits to flowers with a high amount of nectar, and a still high pollen availability on anthers and low pollen deposition on stigmas. We found that during most of the period of anthesis, nectar standing crop volume was positively correlated with the number of pollen grains remaining in the anthers, and negatively with the number of pollen grains deposited on the stigma. CONCLUSIONS: Nectar secretion patterns can function as a manipulator of pollinating bats in H. neesianus. We propose that the assessment of variability in nectar secretion in response to removal, and the correlation between nectar standing crop and relative pollen transfer throughout anthesis should be considered in order to understand the role of nectar in the manipulation of pollinators.

Influence of landscape ecology and physiological implications in bats from different trophic guilds.

Bats may serve as bioindicators of human impact on landscape ecology. This study aimed to evaluate the health condition of bats from different food guilds captured in two areas with different land use profiles in Brazil and to compare data on the oxidant-antioxidant balance and histopathological changes due to different anthropogenic pressures. Bats were collected from a protected area in Serra do Cipó National Park (SCNP), MG, Brazil, and an area with intense agricultural activity in the municipality of Uberaba (UB), MG, Brazil. Despite the differences in land use and occupation between the studied areas, bats showed similar responses. However, the trophic guilds were affected differently. Frugivorous bats in both areas showed lower activities of the enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST) and concentrations of malondialdehyde (MDA) than other guilds, which can be explained by the greater intake of antioxidants from the diet in addition to the lower production of reactive oxygen species (ROS). Histopathological analysis of the livers revealed that the animals had a similar prevalence in the two areas, with some differences related to guilds. Compared with other bats, hematophagous bats from SCNP had a higher prevalence of steatosis and, together with frugivorous bats from Uberaba, had higher frequencies of ballooning degeneration, suggesting that these animals are subjected to anthropogenic factors capable of inducing disturbances in hepatic metabolism. Hematophagous bats from Uberaba had a higher prevalence of portal inflammation, while insectivorous bats from Uberaba had a higher prevalence of lobular and portal inflammation. The profiles of use and occupation of the areas are different; Uberaba bats seem to face worse conditions because they show more liver damage owing to lipoperoxidation.

The acute phase response in bats (Carollia perspicillata) varies with time and dose of the immune challenge.

The acute phase response (APR) is a core component of the innate immune response and represents the first line of immune defense used in response to infections. Although several studies with vertebrates reported fever, a decrease in food intake and body mass, and an increase in neutrophil/lymphocyte ratio and total white blood cell count after lipopolysaccharide (LPS) inoculation, there was great variability in the magnitude of these responses. Some of these differences might reflect, to some extent, differences in the time of endotoxin inoculation (during active or rest periods) and dose. Therefore, our study tested the interplay between LPS dose and time of injection on selected physiological (fever and increase in total white blood cell count and neutrophil/lymphocyte ratio) and behavioral (food intake) components of the APR using a Neotropical fruit-eating bat (Carollia perspicillata) as a model organism. We predicted that LPS would trigger a dose- and time-dependent response in APR components. APR components were assessed in rest and active periods after injection of three doses of LPS (5, 10 and 15 mg kg-1 LPS). The results indicate a more robust decrease in food intake at higher doses during the active period, while increased neutrophil/lymphocyte ratio was more robust during the active period regardless of dose. Furthermore, the skin temperature increase lasted longer at higher doses regardless of the timing of injections. Our study offers important insights into the dependence of time as well as the LPS dosage effect in the APR of bats, and how they deal with the magnitude of infections at different times of day.

Morphophysiological alterations in fruit-eating bats after oral exposure to deltamethrin.

Deltamethrin (DTM) is a synthetic pyrethroid widely used in the cultivation and management of several crops due to its insecticidal action. Application to crops of pyrethroids such as DTM can result in the exposure of water and fruit consumed by fruit bats having a high pyrethroid content which may be harmful. Therefore the objective of this study was to evaluate the effects of short-term oral exposure of the fruit-eating bats (Artibeus lituratus) to two concentrations of DTM (0.02 and 0.04 mg/kg of papaya) on histopathology of the intestine, liver and kidney. The intestine of the animals exposed to both concentrations showed inflammatory infiltrate, degeneration, necrosis and goblet cell hyperplasia as the most frequent pathologies. Besides, the acid mucins showed an increase in the frequency of non-viable cells. The liver showed hepatocyte vacuolizatio and nuclear enlargement, as well as inflammatory infiltrate and steatosis. The kidneys of the exposed animals showed and inflammatory infiltrate, benign nephrosclerosis, vacuolization and necrosis. Also, DTM reduced nitric oxide synthesis, decreased glomerular diameter and increased glycogen percentage in the proximal tubules. Our results suggest that acute exposure to DTM at low concentrations has the potential to induce pronounced histopathological changes in vital organs, such as intestine, liver and kidney of fruit-eating bats.

The prefrontal cortex of the Mexican free-tailed bat is more selective to communication calls than primary auditory cortex.

In this study, we examined the auditory responses of a prefrontal area, the frontal auditory field (FAF), of an echolocating bat (Tadarida brasiliensis) and presented a comparative analysis of the neuronal response properties between the FAF and the primary auditory cortex (A1). We compared single-unit responses from the A1 and the FAF elicited by pure tones, downward frequency-modulated sweeps (dFMs), and species-specific vocalizations. Unlike the A1, FAFs were not frequency tuned. However, progressive increases in dFM sweep rate elicited a systematic increase of response precision, a phenomenon that does not take place in the A1. Call selectivity was higher in the FAF versus A1. We calculated the neuronal spectrotemporal receptive fields (STRFs) and spike-triggered averages (STAs) to predict responses to the communication calls and provide an explanation for the differences in call selectivity between the FAF and A1. In the A1, we found a high correlation between predicted and evoked responses. However, we did not generate reasonable STRFs in the FAF, and the prediction based on the STAs showed lower correlation coefficient than that of the A1. This suggests nonlinear response properties in the FAF that are stronger than the linear response properties in the A1. Stimulating with a call sequence increased call selectivity in the A1, but it remained unchanged in the FAF. These data are consistent with a role for the FAF in assessing distinctive acoustic features downstream of A1, similar to the role proposed for primate ventrolateral prefrontal cortex.NEW & NOTEWORTHY In this study, we examined the neuronal responses of a frontal cortical area in an echolocating bat to behaviorally relevant acoustic stimuli and compared them with those in the primary auditory cortex (A1). In contrast to the A1, neurons in the bat frontal auditory field are not frequency tuned but showed a higher selectivity for social signals such as communication calls. The results presented here indicate that the frontal auditory field may represent an additional processing center for behaviorally relevant sounds.

How aerial insectivore bats of different sizes respond to nightly temperature shifts.

Small, volant and nocturnal, bats face strong challenges to avoid heat loss. Among aerial insectivores, body mass varies by two orders of magnitude between the smallest and the largest species. At low temperatures, physiological constraints should be harsher for smaller bats, as they lose more heat through their body surface than larger species. So, temperature variations should lead to distinct behavioural responses by bats of different body masses. Also, because they feed on arthropods, dependent on ambient temperature, aerial insectivores should halt feeding at low temperatures. Using ultrasound detectors and temperature and humidity sensors, we investigated how aerial insectivores of the coldest region in austral Brazil respond to nightly temperature variations and compared those responses between guilds of distinct body masses. We predict that smaller bats reduce their activity faster than larger bats, but that foraging should reduce simultaneously in the two guilds, as they depend on ectothermic prey. Bat activity reduced significantly below 12 °C. Larger bats maintained their activity at temperatures where the activity of smaller bats had already halted. However, larger bats foraged mostly during the first half of the night, at higher temperatures than those chosen by smaller bats to forage. We associate these differential responses to the thermal convection process, which may increase prey availability at higher altitudes, where larger molossids are known to forage. Smaller species, mostly edge-space hunters, probably take advantage of less variable prey availability during the night, resulting in a more regular behavioural pattern of navigation and foraging.

First evidence of frugivory in Gardnerycteris crenulatum (Chiroptera: Phyllostomidae) / Primera evidencia de frugivoría en Gardnerycteris crenulatum (Chiroptera: Phyllostomidae)

Gardnerycteris crenulatum is a bat species restricted to South America, being particularly rare in lowland rainforests. It is characterized by a diet composed mainly of arthropods and small vertebrates, with no confirmed evidence of fruit consumption. Here, we provide the first records of seeds in the diet of G. crenulatum. The seeds were found in the feces of two individuals captured in late-successional forests in the Colombian Amazon (one pregnant female and one adult male), that belonged to Piper sp. (n = 125) and Cecropia engleriana (n = 3). In germination experiments, only Piper seeds germinated (8%). Insectivores can potentially perform other functions than the role assigned to their corresponding guild. More research is needed on the natural history and ecology of G. crenulatum to elucidate its possible role as seed disperser.(AU)

Gardnerycteris crenulatum es una especie de murciélago restringida a América del Sur, siendo particularmente rara en los bosques húmedos de tierras bajas. Se caracteriza por una dieta compuesta principalmente de insectos, artrópodos y pequeños vertebrados, sin evidencia confirmada de consumo de frutos. En esta nota, reportamos los primeros registros de semillas en la dieta de G. crenulatum. Las semillas fueron encontradas en las fecas de dos individuos capturados en bosques de sucesión avanzada en la Amazonía colombiana (una hembra preñada y un macho adulto), pertenecientes a Piper sp. (n = 125) y Cecropia engleriana (n = 3). En experimentos de germinación, solo germinaron las semillas de Piper sp. (8%). Los insectívoros pueden realizar potencialmente otras funciones además del papel asignado a su gremio correspondiente. Es necesario desarrollar más investigaciones sobre la historia natural y la ecología de G. crenulatum para dilucidar su posible papel como dispersor de semillas.(AU)

Morphometrics of the Indian false vampire bat (Megaderma lyra) from district Jhelum, Pakistan / Morfometria do falso morcego vampiro indiano (Megadermalyra) do distrito de Jhelum, Paquistão

During the present study thirteen Megaderma lyra bats were observed roosting in dark, domed shaped room of Rohtas Fort, district Jhelum. Out of these, six specimens were captured from the roosting site, using hand net. All captured specimens were male. These bats were identified through their unique facial features, an erect and elongated nose-leaf, large oval ears that joined above the forehead and no tail. Mean head and body length of captured specimens was 80 mm, forearm length was 67 mm while average lengths of 3rd, 4th and 5th metacarpals were 51.73 mm, 55.17 mm and 60.42 mm, respectively. Mean skull length was 29.84 mm, breadth of braincase was 12.77 mm. Average Penis length of two specimens was 6.6 mm and total bacular length was 3.08 mm respectively. This is the first record of Megaderma lyra from district Jhelum.(AU)

Durante o presente estudo, 13 morcegos Megadermalyra foram observados empoleirados em uma sala escura em forma de cúpula no Forte Rohtas, distrito de Jhelum, dos quais 6 espécimes foram capturados no local usando rede manual. Todos os espécimes capturados eram machos. Esses morcegos foram identificados por suas características faciais únicas, uma folha nasal ereta e alongada, grandes orelhas ovais que se juntam acima da testa e sem cauda. O comprimento médio da cabeça e do corpo dos espécimes capturados foi de 80 mm, o comprimento do antebraço foi de 67 mm, enquanto os comprimentos médios do 3º, 4º e 5º metacarpos foram de 51,73 mm, 55,17 mm e 60,42 mm, respectivamente. O comprimento médio do crânio foi de 29,84 mm, e a largura da caixa craniana, de 12,77 mm. O comprimento médio do pênis de duas amostras foi de 6,6 mm, e o comprimento total do báculo foi de 3,08 mm. Este é o primeiro registro de Megadermalyra no distrito de Jhelum.(AU)

Cytoarchitecture of the medial nucleus of trapezoid body of three neotropical species of bats (Noctilio leporinus, Phyllostomus hastatus, and Carollia perspicillata) with different foraging behavior / Citoarquitetura do núcleo medial do corpo trapezoidal de três espécies neotropicais de morcegos (Noctilio leporinus, Phyllostomus hastatus e Carollia perspicillata) com diferentes comportamentos de forrageamento

The present study was taken to test the hypothesis that the medial nucleus of the trapezoid body (MNTB) of echolocating neotropical bats with different foraging behavior will exhibit morphological variations in relative size, degree of complexity and spatial distribution. The brains were collected from six male adult bats of each species: Noctilio leporinus (fish-eating), Phyllostomus hastatus (carnivorous/ omnivorous) and Carollia perspicillata (fruit-eating) and were double-embedded and transverse serial sections were cut and stained with cresyl fast violet. The results showed that the MNTB is well developed in all the bats in general and the mean length of the MNTB was 1160 ± 124 µm in N. leporinus, 400 ± 59 µm in P. hastatus and 320 ± 25µm in C. perspicillata. The body and brain weight do not reflect proportionately on the size of the MNTB in the present study. The hearing frequency spectrum did not covary with the size of the MNTB among the bats studied. The MNTB is clearly demarcated from the ventral nucleus of the trapezoid body (VNTB) only in P. hastatus. The MNTB comprised mainly three types of cells in all three bats: dense-staining multipolar cells (12.5 µm and 25.0 µm diameter); light-staining multipolar cells measuring (12.5 µm and 25.0 µm diameter) and light-staining round cells (5.0 µm diameter). The large sized MNTB was observed in N. leporinus, which suggests that it relies heavily on echolocation whereas P. hastatus and C. perspicillata use echolocation as well but also rely on hearing, smell and vision.(AU)

O presente estudo foi realizado para testar a hipótese de que o núcleo medial do corpo trapezoide (MNTB) de morcegos neotropicais ecolocativos com comportamento forrageiro diferente apresenta variações morfológicas no tamanho relativo, grau de complexidade e distribuição espacial. Os cérebros foram coletados de seis morcegos machos adultos de cada espécie, Noctilio leporinus (comedor de peixe), Phyllostomus hastatus (carnívoro/onívoro) e Carollia perspicillata (comedor de frutas), e foram seccionados em série e seções seriais transversais duplas e coradas com cresil violeta. Os resultados mostraram que o MNTB é bem desenvolvido em todos os morcegos em geral e que o comprimento médio do MNTB foi de 1.160 ± 124 µm em N. leporinus, 400 ± 59 µm em P. hastatus e 320 ± 25 µm em C. perspicillata. O peso corporal e cerebral não reflete proporcionalmente o tamanho do MNTB no presente estudo. O espectro da frequência auditiva não covaria com o tamanho do MNTB entre os morcegos estudados. O MNTB é claramente demarcado do núcleo ventral do corpo trapezoidal (VNTB) apenas em P. hastatus. O MNTB compreendia principalmente três tipos de células nos três morcegos: células multipolares de coloração densa (12,5 µm e 25,0 µm de diâmetro), células multipolares de coloração clara (12,5 µm e 25,0 µm de diâmetro) e células redondas manchadas de luz (5,0 µm de diâmetro). O MNTB de grande porte foi observado em N. leporinus, o que sugere que ele depende muito da ecolocalização, enquanto P. hastatus e C. perspicillata também usam a ecolocalização, mas dependem da audição, olfato e visão.(AU)

Bioacoustics for in situ validation of species distribution modelling: An example with bats in Brazil.

Species distribution modelling (SDM) gained importance on biodiversity distribution and conservation studies worldwide, including prioritizing areas for public policies and international treaties. Useful for large-scale approaches and species distribution estimates, it is a plus considering that a minor fraction of the planet is adequately sampled. However, minimizing errors is challenging, but essential, considering the uses and consequences of such models. In situ validation of the SDM outputs should be a key-step-in some cases, urgent. Bioacoustics can be used to validate and refine those outputs, especially if the focal species' vocalizations are conspicuous and species-specific. This is the case of echolocating bats. Here, we used extensive acoustic monitoring (>120 validation points over an area of >758,000 km2, and producing >300,000 sound files) to validate MaxEnt outputs for six neotropical bat species in a poorly-sampled region of Brazil. Based on in situ validation, we evaluated four threshold-dependent theoretical evaluation metrics' ability in predicting models' performance. We also assessed the performance of three widely used thresholds to convert continuous SDMs into presence/absence maps. We demonstrated that MaxEnt produces very different outputs, requiring a careful choice on thresholds and modeling parameters. Although all theoretical evaluation metrics studied were positively correlated with accuracy, we empirically demonstrated that metrics based on specificity-sensitivity and sensitivity-precision are better for testing models, considering that most SDMs are based on unbalanced data. Without independent field validation, we found that using an arbitrary threshold for modelling can be a precarious approach with many possible outcomes, even after getting good evaluation scores. Bioacoustics proved to be important for validating SDMs for the six bat species analyzed, allowing a better refinement of SDMs in large and under-sampled regions, with relatively low sampling effort. Regardless of the species assessing method used, our research highlighted the vital necessity of in situ validation for SDMs.

A multifaceted approach to understanding bat community response to disturbance in a seasonally dry tropical forest.

Given widespread habitat degradation and loss, reliable indicators are needed that provide a comprehensive assessment of community response to anthropogenic disturbance. The family Phyllostomidae (Order Chiroptera) has frequently been the focus of research evaluating bats' response to habitat disturbance in seasonally dry tropical forests (SDTFs). However, few studies compare this family to the larger bat assemblage to assess its efficacy as a bioindicator. We compared community and species-specific attributes of understory phyllostomid and all understory bat species: (1) along a gradient of habitat disturbance within a human-modified SDTF landscape; and (2) between forest and riparian habitats within each disturbance level. We captured 290 individuals belonging to 13 species and 4 families. Phyllostomid species exhibited greater sensitivity to disturbance than the understory bat community as a whole based on richness and beta diversity. Both groups were more sensitive to disturbance in forest than riparian habitat, but phyllostomid species were more likely to be lost from highly disturbed forest habitat. The two dominant species declined in abundance with disturbance but variation in body condition was species-specific. These results suggest that Phyllostomidae are more effective indicators of human disturbance in SDTF than the understory bat community as a whole and evaluation of bats' response to disturbance is best accomplished with a multifaceted approach.

Socio-spatial organization reveals paternity and low kinship in the Honduran white bat (Ectophylla alba) in Costa Rica.

Ectophylla alba is a tent-making bat that roosts in mixed-sex clusters comprising adults and offspring. Our goal was to determine the genetic identity of individuals belonging to different roosting groups. We tested the hypothesis of kin selection as a major force structuring group composition. We used 9 microsatellites designed for E. alba to determine the genetic identity and probability of parentage of individuals. We analyzed parentage and kinship using the software ML-Relate, GenAIEx, and Cervus. The obtained relationship probabilities (0.5) revealed a clear maternal relationship between female adults and offspring with allele compatibility, and at least 5 relationships between male adults and pups. We found a low degree of relatedness within roosting groups. Between roosting groups at different sites, the mean probability of a half-sibling relationship ranged from 0.214 to 0.244 and, for full-sibling relationship, from 0.383 to 0.553. Genetically, adult individuals were poorly related within clusters, and kinship as an evolutionary force could not explain group membership.