Saccopteryx Bilineata Research Articles

Observations of a greater sac-winged bat pup (Saccopteryx bilineata) with a chromatic disorder

Abstract Chromatic disorders in bats are typically documented by brief, incidental observations of individuals at day roosts or by accidental captures during mist-netting. Such descriptions usually lack observations on social behaviour including interactions between bats with aberrant pigmentation and other individuals. Here, we report the first observation of leucism in the greater sac-winged bat Saccopteryx bilineata. Over the course of six weeks, we were able to follow the development of a wild pup with a conspicuous aberrant pigmentation, by observing it in its day roost. Our observations indicate that the vocal and behavioural development of the pup was entirely normal, as well as the integration into its social group. After six weeks, when the pup was already foraging individually, it did not return to its colony in the morning, indicating that it may have been preyed on.

Bats, Bacteria, and Bat Smell V.2.0: Repeatable Sex-Specific Differences in Scent Organ Microbiota

Reproducibility is a fundamental principle in science, ensuring reliable and valid findings. However, replication studies are scarce, particularly in ecology, due to the emphasis on novelty for publication. We explored the possibility of replicating original findings in the field of microbial and chemical ecology by conducting a conceptual replication of a previous study analysing the sex-specific differences in the microbial communities inhabiting the wing sacs, a scent organ with crucial functions in olfactory communication, of greater sac-winged bat (Saccopteryx bilineata). In the original study, the skin swabs from the antebrachial wing sacs of the males and wing sac rudiments of the females were analysed using culture-dependent methods to test sex-specific differences. The authors demonstrated that males have lower microbial richness and different microbial composition than females. We attempted to reproduce these findings using 16S rRNA sequencing, which offers improved accuracy in pinpointing microbial members than culture-dependent methods because of advanced statistical methods. Our study validated the original study’s findings: Males had a lower microbial richness, and the community composition differed between the sexes. Furthermore, in the current study, males had an increased abundance of bacteria that might potentially be involved in odour production and degradation of malodorous substances and antimicrobial production. Our conceptual replication study corroborated that microbes can play a role in shaping their host’s olfactory phenotype and consequently influence sexual selection. Furthermore, the current study emphasises the importance of replication efforts and hopefully encourages a culture that values replication studies in scientific practice.

Review of ocular alterations in bats in America and notes on a new case for Saccopteryx bilineata (Chiroptera: Emballonuridae)

Abstract Morphological abnormalities in bats are rarely reported and, particularly, ocular problems are relatively scarce in the literature. We present a review of the records of ocular alterations in bats of the American continent and document for the first time a case of ocular alteration in the species Saccopteryx bilineata in northern Colombia. In this study we found cases of corneal opacity (5/19 individuals), lesions and trauma, microphthalmia (4/19 individuals), anophthalmia (4/19 individuals) and adnexal diseases (2/19 individuals). We encourage researchers to report their observations of bats with ocular anomalies, as this information could be useful for estimating occurrence rates and addressing questions associated with the social behaviour of the species and on their effects on natural populations.

Description of the echolocation pulses of insectivorous bats with new records for Southwest Colombia

Despite the high diversity of bats in neotropics, traditional methods such as mist nets, harp traps and roost detection have limitations in capturing that diversity in a landscape, with most detected species restricted to those that forage in the undergrowth or enclosed spaces. Therefore, acoustic records become a tool that complements and enhances the efforts to get more complete bat inventories while avoiding alterations in usual foraging activities and disruption in their life cycles. This study describes the acoustic parameters (spectral and temporal variables) of the echolocation pulses of insectivorous bats to characterise different species of bats in Southwest Colombia acoustically. We recorded echolocation calls between December 2017 and May 2020 in the Andean and Pacific regions of the Department of Nariño. We analysed 81 sequences of echolocation calls from eight bat species belonging to three families: Vespertilionidae, Molossidae and Emballonuridae. We perform recordings on free-flying bats with identity corroboration by capture for recording in flight rooms and examination in the hand. Myotis riparius and Lasiurus blossevillii were recorded for the first time in the Nariño Department. M. albescens, M. keaysi, M. riparius and L. blossevillii (Vespertilionidae) had pulses of frequency modulated (FM) with a quasi-constant frequency (QCF) ending; Molossus molossus, Tadarida brasiliensis and Promops centralis (Molossidae) had pulses with constant frequency (CF) and QCF; and Saccopteryx bilineata (Emballonuridae) had pulses with QCF. This study contributes to the efforts to facilitate the identification of insectivorous bats of the Neotropics using the acoustic monitoring approaches, represents a reference to compare the acoustic studies in Southwestern Colombia and contributes to increasing our knowledge of the bat diversity in the region.

Leptospira spp. detection in bats from the Peninsula of Yucatán, México

The records of Leptospira spp. in bats from México are scarce. It is known that several species of bats are hosts of pathogenic Leptospira spp.; therefore, they participate in the epidemiological cycle and can generate transmission scenarios to people and animals. The aim was to detect the DNA of Leptospira spp. in bats captured in four sites from the Yucatán Peninsula, México. A kidney fragment was collected from the bats and used to extract genomic DNA. Using a PCR, the DNA of Leptospira spp. was detected. Fifty–four bats of the species Desmodus rotundus, Mimon cozumelae, Pteronotus mesoamericanus, Pteronotus fulvus, Nyctinomops laticaudatus, Peropteryx macrotis, Molossus nigricans, Molossus aztecus, Noctilio leporinus, Saccopteryx bilineata and Mormoops megalophylla were studied. The PCR yielded a total frequency of Leptospira spp. of 44.4% (24/54, 95% CI 36.2–71.7%). Species with at least one positive individual were D. rotundus, M. cozumelae, P. mesoamericanus, N. laticaudatus, P. macrotis, M. nigricans, N. leporinus, M. aztecus, and S. bilineata. A high frequency of Leptospira spp. was found in different species of bats belonging to several trophic guilds. The presence of Leptospira spp. in bats is relevant for Public and Animal Health because the evidence indicates that they can generate zoonotic transmission cycles.

In silico analysis of ACE2 from different animal species provides new insights into SARS-CoV-2 species spillover.

Aim: This study aimed to analyze the phylogenetic relationships between the ACE2 of humans and other animals and investigate the potential interaction between SARS-CoV-2 RBD and ACE2 of different species. Materials & methods: The phylogenetic construction and molecular interactions were assessed using computational models. Results & conclusion: Despite the evolutionary distance, 11 species had a perfect fit for the interaction between their ACE2 and SARS-CoV-2 RBD (Chinchilla lanigera, Neovison vison, Rhinolophus sinicus, Emballonura alecto, Saccopteryx bilineata, Numida meleagris). Among them, the avian N. meleagris was reported for the first time in this study as a probable SARS-CoV-2 host due to the strong molecular interactions. Therefore, predicting potential hosts for SARS-CoV-2 for understanding the epidemiological cycle and proposal of surveillance strategies.

Thomas H. Kunz

Thomas H. Kunz

Small mammals from the Seasonally Dry Tropical Forests of the Huallaga river basin and new records for San Martín department, Peru

The Seasonally Dry Tropical Forests in Peru are well known for their bird and plant diversity and endemicity, but little is known about the diversity of small mammals. We report the diversity of small volant and non-volant mammals from the Seasonally Dry Tropical Forests of the Huallaga river basin in the San Martín Department, working on both sides of the river, making a sampling effort of 3060 traps-night for non-volant and 104 mist nets-night for volant mammals. We recorded 29 species, including five marsupials, three rodents, and 21 bats. Among the bats, phyllostomids were the most diverse group with 16 species. Short-tailed Spiny-rat, Proechimys brevicauda (Günther, 1877) and Seba's Short-tailed Bat, Carollia perspicillata (Linnaeus, 1758), featured the highest relative abundance. In addition, we report the first records for the San Martín Department of Peropteryx macrotis (Wagner, 1843), Saccopteryx bilineata (Temminck, 1838), Lonchorhina aurita Tomes, 1863, Vampyriscus bidens (Dobson, 1878), and Myotis simus Thomas, 1901. The species richness and diversity indices indicate the study site has a high diversity value; however, fragmentation and rapid changes in land-use are the main threats faced by the biodiversity of these dry forests.

Evidence of female preference for odor of distant over local males in a bat with female dispersal

AbstractGeographic variation of sexually selected male traits is common in animals. Female choice also varies geographically and several studies found female preference for local males, which is assumed to lead to local adaptation and, therefore, increases fitness. As females are the nondispersing sex in most mammalian taxa, this preference for local males might be explained by the learning of male characteristics. Studies on the preference of females in female-dispersing species are lacking so far. To find out whether such females would also show preferences for local males, we conducted a study on greater sac-winged bats (Saccopteryx bilineata), a species where females disperse and males stay in their natal colony. Male greater sac-winged bats possess a wing pouch that is filled with odoriferous secretion and fanned toward females during courtship display. In a combination of chemical analysis and behavioral preference tests, we analyzed whether the composition of wing sac secretion varies between two geographically distinct populations (300 km), and whether females show a preference for local or distant male scent. Using gas chromatography, we found significant differences in the composition of the wing sac odors between the two geographically distinct populations. In addition, the behavioral preference experiments revealed that females of both populations preferred the scent of geographically distant males over local males. The wing sac odor might thus be used to guarantee optimal outbreeding when dispersing to a new colony. This is—to our knowledge—the first study on odor preference of females of a species with female-biased dispersal.

REFUGIOS Y SITIOS DE PERCHA DE Saccopteryx bilineata Temminck, 1838 (Chiroptera : Emballonuridae) EN EL CARIBE COLOMBIANO

Saccopteryx bilineata is a bat of wide geographical distribution in the Neotropics, but in Colombia there is very little information about its biology and roost ecology. This contribution presents a description of the shelters that S. bilineata uses in the Colombian Caribbean region, especially in areas of tropical dry forest. Although it has been documented that it shares shelters with many species of bats, this work presents the first record where S. bilineata shares refuge with Molossus molossus and the use as shelters or roosting sites of species of Brownea ariza, Caesalpinea coriaria and Ceiba pentandra. The high ecological plasticity of the species is ratified in terms of the use of available environments and shelters, as well as cohabiting with other bat species.

Cytogenetic Investigations in Emballonuroidea. III. Extensive Chromosomal Reorganization Characterizes the Karyotype of Saccopteryx bilineata

The only representatives of Emballonuridae in the Neotropics are Diclidurini from the subfamily Emballonurinae. In this tribe, karyotype comparison based on G-banding patterns has revealed extensive chromosomal divergence. Here, we present for the first time a detailed karyotype analysis of a Diclidurini species, Saccopteryx bilineata (SBI), by G-banding and cross-species fluorescence in-situ hybridization (FISH) with Myotis myotis (Vespertilionidae) painting probes. The 25 evolutionarily conserved units (ECUs) ancestral to all Chiroptera were found as 37 segments on the 2n = 26 SBI karyotype. Comparison with the karyotype of another Emballonuridae (Emballonura monticola) from South-East Asia revealed a single common derived segment combination, MMY3+MMY22i, pointing to a fast karyotype evolution in Emballonurinae.

Pup Directed Vocalizations of Adult Females and Males in a Vocal Learning Bat

Social feedback plays an important role in human language development and in the vocal ontogeny of non-human animals. A special form of vocal feedback in humans, infant-directed speech – or motherese –facilitates language learning and is socially beneficial by increasing attention and arousal in the child. It is characterized by high pitch, expanded intonation contours and slower speech tempo. Furthermore, the vocal timbre (i.e. ’color’ of voice) of motherese differs from the timbre of adult-directed speech. In animals, pup-directed vocalizations are very common, especially in females. But so far there is hardly any research on whether there is a similar phenomenon as motherese in animal vocalizations. The greater sac-winged bat, Saccopteryx bilineata, is a vocal production learner with a large vocal repertoire that is acquired during ontogeny. We compared acoustic features between female pup-directed and adult-directed vocalizations and demonstrated that they differed in timbre and peak frequency. Furthermore, we described pup-directed vocalizations of adult males. During the ontogenetic period when pups’ isolation calls (used to solicit maternal care) are converging towards each other to form a group signature, adult males also produce isolation calls. Pups’ isolation calls are acoustically more similar to those of males from the same social group than to other males. In conclusion, our novel findings indicate that parent-offspring communication in bats is more complex and multifaceted than previously thought, with female pup-directed vocalizations reminiscent of human motherese and male pup-directed vocalizations that may facilitate the transmission of a vocal signature across generations.

Comparison of methods for rhythm analysis of complex animals' acoustic signals.

Analyzing the rhythm of animals' acoustic signals is of interest to a growing number of researchers: evolutionary biologists want to disentangle how these structures evolved and what patterns can be found, and ecologists and conservation biologists aim to discriminate cryptic species on the basis of parameters of acoustic signals such as temporal structures. Temporal structures are also relevant for research on vocal production learning, a part of which is for the animal to learn a temporal structure. These structures, in other words, these rhythms, are the topic of this paper. How can they be investigated in a meaningful, comparable and universal way? Several approaches exist. Here we used five methods to compare their suitability and interpretability for different questions and datasets and test how they support the reproducibility of results and bypass biases. Three very different datasets with regards to recording situation, length and context were analyzed: two social vocalizations of Neotropical bats (multisyllabic, medium long isolation calls of Saccopteryx bilineata, and monosyllabic, very short isolation calls of Carollia perspicillata) and click trains of sperm whales, Physeter macrocephalus. Techniques to be compared included Fourier analysis with a newly developed goodness-of-fit value, a generate-and-test approach where data was overlaid with varying artificial beats, and the analysis of inter-onset-intervals and calculations of a normalized Pairwise Variability Index (nPVI). We discuss the advantages and disadvantages of the methods and we also show suggestions on how to best visualize rhythm analysis results. Furthermore, we developed a decision tree that will enable researchers to select a suitable and comparable method on the basis of their data.

Temperature, rainfall, and moonlight intensity effects on activity of tropical insectivorous bats

AbstractThe extrinsic factors that most influence animal activity are weather and light conditions, which can be assessed at hourly, monthly, and even lunar-cycle timescales. We evaluated the responses of tropical aerial-insectivorous bats to temperature, rainfall, and moonlight intensity within and among nights. Temperature positively affected the activity of two species (Cormura brevirostris and Saccopteryx bilineata). Moonlight reduced Myotis riparius activity and increased the activity of Pteronotus rubiginosus and S. leptura. Rainfall can promote an irregular activity peak during the night compared to nights without rainfall, but the bats in our study were not active for a longer time after a rainfall event. Our findings indicate that moonlight and temperature are the variables with the highest impact on the activity of tropical insectivorous bat species and that some species are sensitive to small variations in rainfall among and within nights.

Bat songs as acoustic beacons - male territorial songs attract dispersing females

Male song in birds and mammals is important for repelling rivals, stimulating mates or attracting them to a specific location. Nevertheless, direct experimental evidence for the mate attraction function of male song is limited to a few studies. Here, we provide strong experimental evidence that male songs attract wild female bats (Saccopteryx bilineata). Playbacks of territorial songs reliably elicited phonotaxis in females but not males. Most females captured during playbacks were subadults searching for new colonies to settle in. In S. bilineata, multiple males sing simultaneously at dawn and dusk, thereby creating a conspicuous chorus which encodes information on colony identity and size. Since territorial songs have a large signalling range, male songs constitute acoustic beacons which enable females to localize new colonies. In our playbacks, females strongly preferred local territorial songs over foreign territorial songs from two different locations, indicating that song familiarity influences phonotaxis. Our study provides the first clear experimental evidence that male song elicits female phonotaxis in a non-human mammal. Bats are an especially promising taxon for studying mammalian song since male song has been described in different species with diverse social organisations and natural histories, thus providing exciting opportunities for phylogenetically controlled comparative studies.

MHC-dependent mate choice is linked to a trace-amine-associated receptor gene in a mammal.

Major histocompatibility complex (MHC) genes play a pivotal role in vertebrate self/nonself recognition, parasite resistance and life history decisions. In evolutionary terms, the MHC’s exceptional diversity is likely maintained by sexual and pathogen-driven selection. Even though MHC-dependent mating preferences have been confirmed for many species, the sensory and genetic mechanisms underlying mate recognition remain cryptic. Since olfaction is crucial for social communication in vertebrates, variation in chemosensory receptor genes could explain MHC-dependent mating patterns. Here, we investigated whether female mate choice is based on MHC alleles and linked to variation in chemosensory trace amine-associated receptors (TAARs) in the greater sac-winged bat (Saccopteryx bilineata). We sequenced several MHC and TAAR genes and related their variation to mating and paternity data. We found strong evidence for MHC class I-dependent female choice for genetically diverse and dissimilar males. We also detected a significant interaction between mate choice and the female TAAR3 genotype, with TAAR3-heterozygous females being more likely to choose MHC-diverse males. These results suggest that TAARs and olfactory cues may be key mediators in mammalian MHC-dependent mate choice. Our study may help identify the ligands involved in the chemical communication between potential mates.

Multidimensionality of Chemical Information in Male Greater Sac-Winged Bats (Saccopteryx bilineata)

The complexity of social signals is thought to depend on the complexity of social systems, but evidence from wild animals is scarce. Here, we investigated the chemical information provided by individual male greater sac-winged bats (Saccopteryx bilineata), a small, long-lived neotropical bat species with a harem-polygynous mating system. We analysed the chemical fingerprints of wing-sac liquids that are displayed by males in front of females. Specifically, we tested if fingerprints of 45 males included information about age (adult, juvenile), year of sampling, and distance between colonies. We confirmed age-specific differences in male-specific substances, but show furthermore that chemical fingerprints correlate with year of collection and distance between colonies. Thus, the wing-sac chemistry of male S. bilineata conveys a multitude of information, which can potentially be used by conspecifics, especially by females to assess the status of potential mates. Our study provides evidence for a multidimensionality of chemical information in a free-ranging mammal with high social complexity.

Emballonuridae Gervais, 1855 (Chiroptera) of Reserva Biológica de Saltinho (Atlantic Forest), in Brazil, revealed by echolocation

Seventeen species of emballonurid bats are known in Brazil, but their distribution is often determined by patchy records. However, due to almost species-specific calls, echolocation can help to refine the distribution of emballonurids. Here we use acoustic samplings to assess and complement the list of emballonurids of Reserva Biológica Saltinho, an important Atlantic Forest remnant in Pernambuco state, Northeastern Brazil. We positively matched calls of Saccopteryx bilineata (Temminck, 1838) that was foraging along forest edges. However, a series of calls significantly different from those emitted by S. bilineata indicate the presence of a second Saccopteryx sonotype in the area. The lower frequencies in this sonotype presumably came from a larger species, indicating the possible existence of an undescribed cryptic species of Saccopteryx. We also detected Centronycteris maximiliani (Fischer, 1829), recorded 35 years after its first record in Pernambuco, and an undetermined species of Peropteryx Peters, 1867. Our data proved that echolocation is a very useful technique for inventorying poorly known and hard-to-capture emballonurid species, with the potential to reveal the cryptic richness.

Responsiveness to conspecific distress calls is influenced by day-roost proximity in bats (Saccopteryx bilineata).

Distress calls signal extreme physical distress, e.g. being caught by a predator. In many bat species, distress calls attract conspecifics. Because bats often occupy perennial day-roosts, they might adapt their responsiveness according to the social relevance in which distress calls are broadcast. Specifically, we hypothesized that conspecific distress calls broadcast within or in proximity to the day-roost would elicit a stronger responsiveness than distress calls broadcast at a foraging site. We analysed the distress calls and conducted playback experiments with the greater sac-winged bat, Saccopteryx bilineata, which occupies perennial day-roosts with a stable social group composition. S. bilineata reacted significantly differently depending on the playback's location. Bats were attracted to distress call playbacks within the day-roost and in proximity to it, but showed no obvious response to distress call playbacks at a foraging site. Hence, the bats adapted their responsiveness towards distress calls depending on the social relevance in which distress calls were broadcast. Distress calls within or in proximity to the day-roost are probably perceived as a greater threat and thus have a higher behavioural relevance than distress calls at foraging sites, either because bats want to assess the predation risk or because they engage in mobbing behaviour.

Distress Calls of a Fast-Flying Bat (Molossus molossus) Provoke Inspection Flights but Not Cooperative Mobbing.

Many birds and mammals produce distress calls when captured. Bats often approach speakers playing conspecific distress calls, which has led to the hypothesis that bat distress calls promote cooperative mobbing. An alternative explanation is that approaching bats are selfishly assessing predation risk. Previous playback studies on bat distress calls involved species with highly maneuverable flight, capable of making close passes and tight circles around speakers, which can look like mobbing. We broadcast distress calls recorded from the velvety free-tailed bat, Molossus molossus, a fast-flying aerial-hawker with relatively poor maneuverability. Based on their flight behavior, we predicted that, in response to distress call playbacks, M. molossus would make individual passing inspection flights but would not approach in groups or approach within a meter of the distress call source. By recording responses via ultrasonic recording and infrared video, we found that M. molossus, and to a lesser extent Saccopteryx bilineata, made more flight passes during distress call playbacks compared to noise. However, only the more maneuverable S. bilineata made close approaches to the speaker, and we found no evidence of mobbing in groups. Instead, our findings are consistent with the hypothesis that single bats approached distress calls simply to investigate the situation. These results suggest that approaches by bats to distress calls should not suffice as clear evidence for mobbing.