Macroderma Gigas Research Articles

Evading the Ghost of Extinction: A Case Study for the Reintroduction of Ghost Bats (Macroderma gigas)

The ghost bat Macroderma gigas (Megadermatidae) is native to Australia. Its current distribution has dramatically contracted northwards in the past 150 years and the extant populations are scattered and isolated due to climatic and anthropogenic factors. To investigate the potential for reintroductions of wild ghost bats into suitable habitats, we examined the potential for refuges located in the southern-most parts of the species’ former range to once again support populations. We identified Drovers Cave, located in Drovers Cave National Park in Western Australia, as a potential reintroduction site and used thermo-hygrochron iButtons to demonstrate that the microclimate conditions within the cave are suitable for ghost bats with temperatures close to 20 °C and 99% humidity throughout a ten-month period (December to September). We also showed that in the Pilbara region, ghost bats are opportunistic and flexible predators relying on small birds and mammal species. After comparing these data with the local fauna species list reported from Drovers Cave National Park, we concluded that the habitat at the proposed reintroduction site could provide sufficient diversity of potential prey species in terms of species richness, but we had no data on their relative abundance.

Distribution of Ghost Bats of the Genus Diclidurus Wied-Neuwied 1820 (Chiroptera: Emballonuridae) in Venezuela, with a Review of Their Vocal Signatures

Distribution of Ghost Bats of the Genus Diclidurus Wied-Neuwied 1820 (Chiroptera: Emballonuridae) in Venezuela, with a Review of Their Vocal Signatures

Species-specific SNP arrays for non-invasive genetic monitoring of a vulnerable bat

Genetic tagging from scats is one of the minimally invasive sampling (MIS) monitoring approaches commonly used to guide management decisions and evaluate conservation efforts. Microsatellite markers have traditionally been used but are prone to genotyping errors. Here, we present a novel method for individual identification in the Threatened ghost bat Macroderma gigas using custom-designed Single Nucleotide Polymorphism (SNP) arrays on the MassARRAY system. We identified 611 informative SNPs from DArTseq data from which three SNP panels (44–50 SNPs per panel) were designed. We applied SNP genotyping and molecular sexing to 209 M. gigas scats collected from seven caves in the Pilbara, Western Australia, employing a two-step genotyping protocol and identifying unique genotypes using a custom-made R package, ScatMatch. Following data cleaning, the average amplification rate was 0.90 ± 0.01 and SNP genotyping errors were low (allelic dropout 0.003 ± 0.000) allowing clustering of scats based on one or fewer allelic mismatches. We identified 19 unique bats (9 confirmed/likely males and 10 confirmed/likely females) from a maternity and multiple transitory roosts, with two male bats detected using roosts, 9 km and 47 m apart. The accuracy of our SNP panels enabled a high level of confidence in the identification of individual bats. Targeted SNP genotyping is a valuable tool for monitoring and tracking of non-model species through a minimally invasive sampling approach.

First record of the ghost bat Diclidurus (Chiroptera, Emballonuridae) in the Atlantic Forest of Alagoas state, Brazil

First record of the ghost bat Diclidurus (Chiroptera, Emballonuridae) in the Atlantic Forest of Alagoas state, Brazil

Diversity of bat ectoparasites from the caves of selected Key Biodiversity Areas in Central Visayas, Philippines

Abstract. Bejec GA, Bucol LA, Ancog AB, Pagente AC, Paneiro JJM, Bejec ALN, Belanizo JD, Tuastomban DJS, Jose RP. 2023. Diversity of bat ectoparasites from the caves of selected Key Biodiversity Areas in Central Visayas, Philippines. Biodiversitas 24(3): 1693-1703. Bats harbor numerous species of ectoparasites, such as ticks and mites. Many bat ectoparasites are implicated as vectors of pathogens ranging from bacteria to protozoa and viruses. Recent studies verified bats as a natural reservoir of multiple zoonotic viruses, including Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS) coronaviruses. This study assessed the composition, diversity, and prevalence of ectoparasites of cave-dwelling bats in the four Key Biodiversity Areas (KBAs) of Central Visayas. A total of 20 species of bats were recorded in the 30 surveyed caves. Of these, 30 species of ectoparasites belonging to eight families (dipteran flies Streblidae and Nycteribiidae, mites Spinturnicidae, Macronyssidae and Trombiculidae, ticks Argasidae and Ixodidae, and Ischnopsyllidae fleas) were collected and identified. Leptotrombidium sp. had the highest number of individuals (n=1,684) harbored in 12 bat host species. The highest prevalence (100%) was noted in four bat host species: Philippine pygmy fruit bat Haplonycteris fischeri Lawrence 1939, Philippine forest roundleaf bat Hipposideros obscurus Peters 1861, Philippine pygmy roundleaf batHipposideros pygmaeus Waterhouse 1843, and Common bent-winged bat Miniopterus schreibersii Kuhl 1817. The lowest prevalence was noted in the Round-eared tube-nosed bat Murina cyclotis Dobson 1872, where no ectoparasite was collected. The highest intensity (n=65) of ectoparasites was observed in the Common Asian ghost bat Megaderma spasma Linnaeus 1758. This study provides essential data for future reference in monitoring bat population status and conservation efforts in the region. Given the close relationship between the local human community and bats (e.g., hunting and consumption), more work is needed to address the potential pathogen risks from zoonotic transmission from bats and ectoparasites.

Novel acoustic lure methodology facilitates detection of the cryptic ghost bat at a landscape scale

Context The conservation of the threatened ghost bat (Macroderma gigas) is currently hampered by a lack of standardised survey methodology for detecting the species away from known roosts. The low amplitude of the species’ echolocation call, together with only sporadic production of social calls while foraging, means that acoustic detection is unreliable. However, the ghost bat is known to be physically responsive to full-spectrum playback of its own social calls when these are broadcast in close vicinity (~100 m) to known roosts. Aims Using a two-phase investigation, we aimed to establish whether playback could be used to detect ghost bats away from the roost, in open woodland habitat in the Northern Territory. Methods In phase one, a trial of paired (active treatment and control) call playback experiments was conducted at three distances (1 km, 2.5 km and 5 km) from four known roosts using the ghost bat’s ‘squabble’ social vocalisation. Call playback, distance, roost and moon phase were used as explanatory variables in an information-theoretic approach using generalised linear models. In phase two, a 65 010-ha survey area was broken into a grid of adjacent hexagons with centroids spaced 5 km apart; replicate surveys using call playback were conducted at each centroid. An occupancy model was used to determine detection probability for the method in the survey area. Key results Ghost bats were successfully detected. In phase one, one model had substantial support and this contained only one variable: that of the presence or absence of the ‘squabble’ vocalisation. In phase two, ‘hotspots’ of ghost bat activity were detected in a region for which records were scant and predominantly historical. The occupancy model identified that 72% of sites were occupied and established a detection probability of 0.505, which provided a cumulative probability of 0.75. Conclusions Our results show that call playback is a reliable method of detecting the cryptic and threatened ghost bat at a landscape scale in the Northern Territory. Implications We suggest that call playback could be used as a standardised survey technique across the range of the ghost bat.

Validation of non-invasive hormone analysis techniques to assist in the future identification of maternal roosts of ghost bats (Macroderma gigas)

The ghost bat (Macroderma gigas) is the largest microbat in Australia and occupies a large but contracting range. The ghost bat is listed as Vulnerable with a decreasing population trend by the IUCN Red List of Threatened Species. They occupy caves, disused mine adits and rock crevices as daytime roosts but distinguishing which are preferred as maternal roosts is challenging as sampling is difficult, and bats are easily disturbed while roosting. Identification of maternal roosts is a priority for conservation and management purposes, and therefore non-invasive hormone analysis was investigated as a potential tool for the future identification of the cave preferences of pregnant individuals. To validate fecal progesterone metabolite analysis techniques, fecal samples were collected from group housed female ghost bats at Perth Zoo between October and January, during the expected parturition period, over three years. Fecal samples were weighed (0.025 g), extracted with 2.5 ml of 80% methanol and analyzed for progesterone metabolite levels by enzyme-immunoassay. Significant elevations in fecal progesterone metabolite levels were detected in a subset of samples collected from co-housed females prior to parturition but not after, providing biological validation of the hormone analysis techniques. Over the three years, four pups were born with birth dates ranging from early November to late December. The mean fecal progesterone metabolite levels of non-pregnant females was significantly lower than those of pregnant females (206.5 ± 102.9 ng/g and 7003.6 ± 6078.0 ng/g respectively). These techniques can be used to monitor and evaluate the reproductive health of ghost bat populations over time and help identify factors influencing maternity roost fidelity. This data will provide valuable information for the conservation and management of the ghost bat and has the potential to be applied to other bat species.

A large, newly discovered ghost bat colony in Queensland

Obtaining accurate counts that do not cause harm to the animals being studied are important for assessing a species’ conservation status. A single evening exodus of ghost bats (Macroderma gigas) was recorded using a thermal imaging camera placed outside the entrance to a cave on Alwal National Park (CYPAL) in September 2022. At least 463 bats were counted, making it the largest known ghost bat colony in Queensland. Further work is required to determine the extent to which this colony is related to other nearby colonies in Cape York Peninsula. Work is also required to identify and reduce threats to this population and ensure its conservation.

Ethogram of Ghost Bat (Macroderma gigas) Behaviours and Associated Social Vocalisations

The ghost bat (Macroderma gigas) is a carnivorous species of bat endemic to northern Australia that roosts in colonies of up to 1,500 individuals. The ghost bat produces a number of social vocalisations, but little is known about the species' behaviour and what role social vocalisations play in interactions between conspecifics. The aim of this study was to construct an ethogram of ghost bat behaviours and to determine the associations between behaviours and social vocalisations. To achieve our aims, we filmed the behaviour of a captive ghost bat colony (one male, five females) using four trail cameras installed within the enclosure over a six-week period, coinciding with the estimated mating season. Video recordings were examined by eye, and solitary and social behaviours were catalogued into distinct behavioural units (e.g. hang-alert, chew, wing-groom, etc.) along with social context and associated social vocalisations, if applicable. To assess the associations between behavioural interactions and social vocalisation types, we combined each of the catalogued social behavioural units into six behavioural classes (eating, grooming, mating, huddling, flying, and fighting) and used generalised linear models to determine which social behavioural classes significantly predicted the production of each vocalisation. There was a strong association between flight behaviour by a member of the colony and the production of the ‘Chirp-trill’ vocalisation by the male member of the colony, suggesting a territorial or mate attraction function. There was also a strong association between fighting behaviour and the production of the ‘Squabble’, ‘Rasp’ and ‘Grumble’ vocalisations, with the Squabble and Rasp likely representing levels of agonistic vocalisations produced by aggressive bats during altercations. The Grumble, on the other hand, was produced by the target of the aggressor and so may function as an appeasement call. The ethogram with its associated social vocalisations provides a formal basis for future behavioural studies in this species and can serve as a template for such studies in other echolocating bats. Our study revealed an unexpected degree of complexity in the behaviour and associated vocalisations in this species and highlights the need for studies of this kind in other bats.

Research priorities for the ghost bat (

The ghost bat (Macroderma gigas) is Australia’s largest echolocating bat. It is restricted to several disjunct populations in the north of the continent, including a population in the Pilbara region of Western Australia. In 2016 the ghost bat was listed as Vulnerable under Australian federal legislation, owing to declining numbers across many regional populations. The most severe threat to ghost bats in the Pilbara region is the destruction and disturbance of habitat due to mining operations, but disturbance to their roosts from other infrastructure developments and changes to and loss of foraging habitat also pose significant threats. A set of research priorities for ghost bats in the Pilbara was developed during a workshop attended by mining industry representatives, environmental consultants, scientists and government regulators. Five research priorities were identified: (1) identify and characterise critical diurnal roosts and foraging habitat; (2) improve knowledge of the distribution, movement and dispersal patterns of ghost bats in the region; (3) improve knowledge of population size, persistence and long-term trends; (4) better understand the cumulative, direct and indirect impacts of mining and other development activities; and (5) better understand the threats posed by fence entanglements, cane toads and feral cats.

Breeding and Post-Breeding Behavior of the Ghost Bat (Macroderma gigas) at Perth Zoo

Understanding the behavior of wildlife in zoo environments is necessary to determine species’ welfare states and minimize stress whilst optimizing social groupings, particularly where breeding programs are being undertaken. This observational study investigated the behavior and welfare of six groupings of ghost bats (Macroderma gigas) across the breeding and post-breeding seasons within Perth Zoo, Western Australia. Scan sampling was used to record behavioral states and interactions along with spatial preferences within enclosures for 198 hours of observations. A total of 11,895 interval observations were conducted during the study period. Exploratory behavior was correlated with enclosure size, with 18.7% of the total observations in the largest enclosure compared with only 7.1% of them in the smallest enclosure. Male ghost bats engaged in negative behaviors in 40.2% of observed male-male interactions, regardless of the season. Non-breeding females engaged in more female-female negative behaviors during the breeding season, while negative behaviors increased in the breeding female group after the end of the breeding season. This study highlights areas where management practice may be optimized in a zoo setting and provides evidence to consider revising standards of enclosure size for chiropteran species. An increase in heating structures and feeding platforms could also reduce the number of negative interactions between individuals. Given that ghost bats in the wild are listed as Vulnerable, zoo population management and breeding may form an integral part of conservation planning for this species in the near future. As the first published study of zoo-housed ghost bats, these findings help provide insight into the behaviors and interactions of ghost bats in different social groupings across the breeding and post-breeding seasons.

The complete mitochondrial genome of the Australian ghost bat Macroderma gigas

The Ghost bat Macroderma gigas is a monotypic bat species that is endemic to northern Australia and named on the basis of the large size of its partially conjoined ears. It is the only carnivorous bat found in Australia and its conservation status is currently listed as Vulnerable. Here, we describe the complete mitochondrial genome of M. gigas and compare it to other vertebrates. The M. gigas circularized mitogenome was 16,661 bp and contained 13 protein-coding genes, two rRNA genes, 22 tRNAs and a control region (D-loop) of 1228 bp. Phylogenetic analysis of available entire mitogenomes reveals that Macroderma gigas is most closely related to the Indian false vampire bat Megaderma lyra in the family Megadermatidae (false vampire bats).

We eat meat: a review of carnivory in bats

Abstract Some bat species in the families Phyllostomidae, Megadermatidae, and Nycteridae have long been known to consume terrestrial vertebrates and, more recently, reports of aerial‐hawking vespertilionid carnivores have surfaced. We review the diets, hunting behaviour and roosting ecology of 17 bat species that are known to consume terrestrial vertebrates: Vampyrum spectrum, Chrotopterus auritus, Trachops cirrhosus, Macroderma gigas, Megaderma (Lyroderma) lyra, Nycteris grandis, Nyctalus lasiopterus, Nyctalus aviator, Ia io, Antrozous pallidus, Cardioderma cor, Phyllostomus hastatus, Mimon (Gardnerycteris) crenulatum, Mimon cozumelae, Tonatia saurophila, Tonatia bidens, and Lophostoma silvicolum. Data on their diet and roosts were obtained from 241 original works, with considerable differences in the amount of research and information available among species. Carnivorous bats were found to belong to an ecologically diverse group and share little but their diet. Therefore, we define a carnivorous bat as a bat that, either year‐round or seasonally, uses terrestrial vertebrates as the main component of its diet, at least in part of its geographic range. We conclude from available data that Mimon crenulatum, Lophostoma silvicolum, Mimon cozumelae, Phyllostomus hastatus, Tonatia bidens, Tonatia saurophila, Cardioderma cor, and Antrozous pallidus use vertebrates as a minor part of their diet and should not be considered carnivorous. The nine other species we reviewed do fit into the definition of carnivorous bats, and can be further subdivided based on their ecology and the seasonality of their habits into three categories: year‐round predominantly gleaning carnivores (Chrotopterus auritus, Trachops cirrhosus, and Vampyrum spectrum), seasonal predominantly gleaning carnivores (Megaderma lyra, Macroderma gigas, and Nycteris grandis) and seasonal aerial‐hawking bird‐eating carnivores (Ia io, Nyctalus aviator, and Nyctalus lasiopterus).

First report of intraspecific variation in wing translucency for a Neotropical bat species

Although most variation regarding bat colouration has been recorded for fur, there have also been a few bat species for which intraspecific variation in wing translucency has been reported. However, all records are from the Paleotropics, with no cases reported for any bat species in the Neotropics. Here we describe the first case of intraspecific variation in wing translucency for a Neotropical bat species, the lesser ghost bat (Diclidurus scutatus). Two individuals captured hundreds of kilometres away from each other in the Brazilian Amazon forest showed distinct patterns in relation to the degree of their wing translucency. While one individual in the North‐eastern Amazon forest had fully translucent wings, the other in the Southern Amazon had whitish opaque wings. We propose three hypotheses to explain this variation, which are related to differences in: (1) light conditions and camouflage in the roost; (2) thermoregulation requirements; and (3) habitat structure relationship with hunting success

Diclidurus albus Wied-Neuwied, 1819 (Mammalia, Chiroptera): Geographic Distribution in Honduras, with New Records Inferred from Acoustic Evidence and Morphology

Information on the distribution of the Northern Ghost Bat, Diclidurus albus, in its natural distribution range, is scarce. In Honduras, four previous records are known. Here we add seven new locations, corresponding to five departments: Atlántida, Choluteca, Copán, Cortés, and Valle. We document the first records in the insular zone of the Gulf of Fonseca. We confirm the presence of D.albus on the northern coast, through records in San Pedro Sula and Jardín Botánico Lancetilla. We expand the distribution range towards the west zone of Honduras, in Copán Ruinas, approximately 63 km from the closest previous record from the year 1937. We update the distribution and perform ecological niche modelling that suggest, a wider presence, mainly in ecosystems associated with aquatic environments and dry forest below 1500 m.a.s.l. We provide the values of the different acoustic parameters, which can serve as a reference for the identification of D. albus at the local level. In addition, morphological, and ecological information is contributed thereby advancing the natural history knowledge of this species.

Development and optimisation of molecular assays for microsatellite genotyping and molecular sexing of non-invasive samples of the ghost bat, Macroderma gigas.

The ghost bat (Macroderma gigas) is endemic to Australia but is under threat, with scarce information available on the genetic health of remaining populations. Here, we develop molecular assays for microsatellite genotyping and molecular sexing of non-invasive samples as a genetic monitoring tool to identify individuals, measure genetic diversity and investigate spatial and temporal patterns of habitat use by ghost bats. We identified novel microsatellites through high-throughput sequencing on the Illumina MiSeq platform. Of 48 loci tested, six markers were added to five previously developed microsatellite loci. We developed three Y-linked (DDX3Y, Zfy and SRY) and one X-linked markers (Zfx) to enable molecular identification of sex. To assess performance, all 11 microsatellite and four sex-linked markers were amplified in three multiplex reactions in 160M. gigas faecal samples from the Pilbara region, Western Australia. The combined markers offered a high level of individual discrimination (PIDsibs = 0.00002) and we detected 19 bats in total (11 males, 4 females and 4 sex undetermined). The number of alleles per locus ranged from 5 to 14 and the average observed and expected heterozygosity across loci were Ho = 0.735 (0.58-0.91) and uHe = 0.785 (0.59-0.89) respectively. Our molecular assays allowed identification of individuals from faecal samples at multiple time points and spatial locations and enabled us to elucidate patterns of habitat usage at the study site. This study highlights the value of our molecular assays as a potential capture-mark-recapture technique for population monitoring for this species.

Ghost bats exhibit informative daily and seasonal temporal patterns in the production of social vocalisations

The ghost bat (Macroderma gigas) is a colonial and highly vocal species that is impacted by human visitation of caves. The ability to document behaviours inside the roost by recording vocalisations could provide an important new tool for the management of this disturbance-prone species by removing the need for in-person confirmation of reproductive activity, and, in turn, identifying roosts of conservation importance. To assess whether vocalisations are indicators of daily and seasonal behavioural events, we aimed to determine whether total vocal activity significantly varied by time of day and time of year and, further, how the relative frequencies of occurrence of three common social vocalisations (‘Chirp-trill’, ‘Squabble’ and ‘Ultrasonic Social’) aligned with previously reported seasonal reproductive behaviour. We recorded sound inside the largest known maternity roost, extracted all vocal signals and classified them into types using semiautomated methods. Total vocal activity varied significantly by time of day and time of year, peaking around sunrise and sunset, and during the mating and nursing seasons. The relative frequencies of occurrence of vocalisation types varied significantly seasonally, with the Chirp-trill and Squabble produced most during the mating season and first flight periods, whereas the Ultrasonic Social peaked during parturition and weaning periods. This timing aligns with a previously suggested vocalisation function, providing further evidence that these signals are important in mating and maternity behaviours. Further, this suggests that peaks in the relative frequency of occurrence of distinct social vocalisations may act as indicators of in-roost reproductive and pup development behaviours and provides a low-disturbance, semiautomated method for using long-term acoustic recordings to study and monitor behaviour in this sensitive species.

First capture of Diclidurus albus Wied-Neuwied, 1820 (Mammalia, Chiroptera, Emballonuridae) from Nicaragua

We report on the first capture and photographs of the Northern Ghost Bat, Diclidurus albus Wied-Neuwied, 1820, from Nicaragua, based on one individual from the Reserva Silvestre Privada Refugio Bartola, department of Río San Juan, southeastern Nicaragua. We provide basic morphological measurements of the individual as well as a distribution map of previous visual sightings and acoustic recordings of this species from Nicaragua.

Determination of the diet of the ghost bat (Macroderma gigas) in the Pilbara region of Western Australia from dried prey remains and DNA metabarcoding

The ghost bat (Macroderma gigas) is listed as Vulnerable in Australia, and is a difficult species to study in the wild. The published literature available on even the most basic aspects of its ecology is limited. This study describes an investigation into the diet of ghost bats occupying the Pilbara region of Western Australia, using identification of dried food remains recovered from beneath roosts in the 1980s and 1990s, and DNA metabarcoding of faecal pellets collected from roost sites during 2011–12. Ghost bat diet in the Pilbara region consists primarily of small mammal and bird species, with a lesser contribution from reptiles (geckoes and skinks) and amphibians. In total, 46 vertebrate taxa were identified, with 32 taxa identified from the dried food remains, and 21 taxa by DNA metabarcoding analysis of the faecal pellets. Only seven of the taxa identified were common to both collection methods, and 32 of those taxa identified represent new prey records for ghost bats in Western Australia, and 19 prey species that had not previously been reported from any other part of Australia. Knowledge of the diet of the ghost bat will provide land managers with important information necessary to ensure the continued survival of this species across its range.

Tracking and tracing central Queensland’s Macroderma – determining the size of the Mount Etna ghost bat population and potential threats

The ghost bat, Macroderma gigas, colony at Mount Etna was at the centre of Australia’s longest-running conservation campaign. To protect the colony the Queensland Government removed recreational facilities and gated caves. The size and genetic diversity of the Mount Etna M. gigas population were estimated using cave searches, direct captures and molecular analysis to determine whether these actions have benefitted the species. In addition, telemetry was undertaken and red fox, Vulpes vulpes, scats analysed to identify possible threats. Results suggest that the population has declined by 79% since the late 1990s, has low microsatellite diversity, low effective population size (Ne) and is undergoing a population bottleneck. VHF- and GPS-collared animals were found to forage over agricultural land up to 11.8 km from their daytime roost, suggesting that poor land management and barbed-wire fences could be potential threats. No ghost bat remains were found in fox scats. We recommend that compliance be increased around Johansen’s Cave to reduce disturbance during the maternity season and landholders be encouraged to undertake management that is sympathetic to ghost bats.