Bat 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.

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.

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).

Using genetic data to predict the vulnerability of a native predator to a toxic invader

Australia has no native toad species, and as a consequence, many Australian pre - dators lack resistance to the toxins of the invasive cane toad Rhinella marina, and die if they ingest one of these toads. Resistance is conferred by a small and consistent genetic change, so genetic data can provide a rapid, non-invasive way to clarify the vulnerability of as-yet-unstudied taxa. To evaluate the hypothesis that a recent decline of ghost bat Macroderma gigas populations in tropical Australia is due to ingestion of cane toads, we sequenced the H1-H2 extracellular domain of the sodium-potassium-ATPase. Two anuran-eating Asian relatives of the Australian species possess the genes that confer bufotoxin resistance, but the ghost bat does not. Like varanid lizards (major victims of the toad invasion), Australian ghost bats appear to have lost their physiological resistance to toad toxins but retained generalist foraging behaviours, potentially including a readiness to attack toads as well as frogs. Our genetic data suggest that cane toads may imperil populations of this iconic predator, and detailed behavioural and ecological studies are warranted.

Avian prey of the Australian Ghost BatMacroderma gigas(Microchiroptera: Megadermatidae): prey characteristics and damage from predation

The Ghost Bat Macroderma gigas is a large (mean mass 150 g) predatory bat of subtropical and tropical Australia. It carries its vertebrate prey to roost caves to be eaten and where remains are dropped and accumulate. Whereas the attack and feeding methods of M. gigas on mammals has been well documented, there is little comparable information relating to avian prey. Using published lists of avian prey and skeletal material collected from a modern Macroderma roost, this study examined the range of bird species eaten by this bat. From the characteristics of these birds, biases towards particular behaviour patterns were identified. Prey masses were used to determine a preferred size range for avian prey. From this information, and assessments of the damage to the bones, inferences were made regarding the capture and processing methods employed by M. gigas for birds. More than 50 species, from a broad taxonomic range, have been recorded as avian prey of the Ghost Bat. These are all essentially diurnal with the...

Flying primates? Megabats have the advanced pathway from eye to midbrain.

The pattern of connections between the retina and midbrain has been determined with electrophysiological and neuroanatomical methods in bats representing the two major subdivisions of the Chiroptera. Megachiropteran fruit bats (megabats), Pteropus spp., were found to have an advanced retinotectal pathway with a vertical hemidecussation of the kind previously found only in primates. In contrast, the microchiropteran bat Macroderma gigas has the "ancestral" or symplesiomorphous pattern of retinotectal connections so far found in all vertebrates except primates. In addition to linking primates and megachiropteran bats, these findings suggest that flight may have evolved twice among the mammals.

New fossil localities for Macroderma (Chiroptera: Megadermatidae) in New South Wales and its past and present distribution in Australia.

Remains of the Ghost Bat Macroderma gigas (Dobson, 1880) are reported from cave deposits at Cliefden, Wellington and Yessabah Caves, New South Wales. These localities lie well south of the previously known range for M. gigas in eastern Australia. Another specimen, from Ashford Cave, N.S.W. , can be identified only as Macroderma sp. All are Quaternary in age. Remains of M. gigas dating from this time are also known from South Australian and Western Australian localities south of the area where the species now occurs. The Ghost Bat is presently found in Queensland, the Northern Territory and as far south as latitude 28oS in Western Australia. Its environments range from dry, hot mulga country to humid, hot rainforest. Previous understanding of the factors limiting the range of M. gigas is inadequate and microclimates of the caves used by this bat may be an important factor.

Josefilaria mackerrasae gen. et sp. nov. (Nematoda: Filarioidea) a parasite of the ghost bat Macroderma gigas Dobson (author's transl)

Josefilaria mackerrasae n. gen., n. sp., a filarial of the ghost bat Macroderma gigas in Australia is described. This filarioid has affinities with the genus Litomosa, but it can be separated by a variety of both more highly evolved characters (buccal capsule reduced to a pre-oesophageal ring; external lateral papillae absent) and primitive characters ("caudal alae" of the male, long and divided oesophagus, vulva not far from the nerve ring, numerous caudal mucrons of the female).