Pteropus Scapulatus Research Articles

Presence of Multiple Herpesvirus Variants in Australian Flying Foxes (Pteropus spp.).

Herpesviruses have been detected in bat species from several countries, with a limited number of studies examining herpesviruses in Pteropus spp. (flying foxes) and no investigation of herpesviruses in Australian flying foxes. We examined the presence and prevalence of herpesviruses in the four mainland Australian flying fox species. A nested PCR targeting highly conserved amino acid motifs in the DNA polymerase (DPOL) gene of herpesviruses was used to analyze 564 samples collected from 514 individual Pteropus scapulatus, Pteropus poliocephalus, Pteropus alecto, and Pteropus conspicillatus. The prevalence of herpesvirus DNA in blood, urine, oral, and fecal swabs from the four species was 17% in P. scapulatus, 11% in P. poliocephalus, 10% in P. alecto, and 9% in P. conspicillatus (31% in P. conspicillatus spleen tissue). Five putative novel herpesviruses were detected. Following PCR amplicon sequence analysis, four of the herpesviruses grouped phylogenetically with the gammaherpesviruses, with nucleotide identities between 79% and 90% to gammaherpesviruses from Asian megabats. A betaherpesvirus was detected in P. scapulatus with 99% nucleotide identity to the partial DPOL gene sequence of an Indonesian fruit bat betaherpesvirus. This study lays the foundation for future epidemiology research of herpesviruses in Australian Pteropus spp. and adds to the discussion of hypotheses surrounding the evolutionary epidemiology of bat-borne viruses on a global scale.

The diet of a specialist nectarivore in Australia: The little red flying‐fox (Pteropus scapulatus, Pteropodidae)

AbstractThe little red flying‐fox (Pteropus scapulatus, Pteropodidae) is the most widely distributed of the four Australian mainland flying‐fox (Pteropus) species. They move very large distances following foraging resources and congregate in large numbers which often causes human‐animal conflict. To better understand the resources that drive these movements and aggregations, we investigated the diet of the little red flying‐fox using data from five sources: (i) faecal eDNA metabarcoding of field sampled little red flying‐foxes; (ii) identification of foraging locations through satellite tracking; (iii) a literature search; (iv) a search of online databases; and (v) an expert survey. Our sources revealed a specialist nectarivore diet containing 204 species, dominated by floral products from the plant family Myrtaceae. We consider a small number of widely occurring and structurally dominant Myrtaceae, particularly from the genera Corymbia, Eucalyptus and Melaleuca, as major diet species that regularly drive mass aggregations. In addition, we consider a moderate number of species dominated by the Myrtaceae as important diet species and a large number of species from diverse taxa as supplementary diet species. Fruit represents approximately 5% of the diet suggesting that the little red flying‐fox is unlikely to be a major pest of horticultural crops or disperser of weeds. The combination of long‐distance movement and a wide range of diet species results in a long‐distance pollination service to many plant species which likely promotes genetic mixing between isolated populations of plants. Our understanding of the little red flying‐fox diet allows us to better predict mass migrations and aggregations at a continental scale and allows us to clearly identify key foraging habitat so that informed management decisions can be made.

A new Hendra virus genotype found in Australian flying foxes

BackgroundHendra virus (HeV) has caused lethal disease outbreaks in humans and horses in Australia. Flying foxes are the wildlife reservoir from which the virus was first isolated in 1996. Following a heat stress mortality event in Australian flying foxes in 2013, a novel HeV variant was discovered. This study describes the subsequent surveillance of Australian flying foxes for this novel virus over a nine year period using qRT-PCR testing of tissues from flying foxes submitted primarily for Australian bat lyssavirus diagnosis. Genome sequencing and characterisation of the novel HeV variant was also undertaken.MethodsSpleen and kidney samples harvested from flying fox carcasses were initially screened with two real-time qRT-PCR assays specific for the prototype HeV. Two additional qRT-PCR assays were developed specific for the HeV variant first detected in samples from a flying fox in 2013. Next-generation sequencing and virus isolation was attempted from selected samples to further characterise the new virus.ResultsSince 2013, 98 flying foxes were tested and 11 were positive for the new HeV variant. No samples were positive for the original HeV. Ten of the positive samples were from grey-headed flying foxes (GHFF, Pteropus poliocephalus), however this species was over-represented in the opportunistic sampling (83% of bats tested were GHFF). The positive GHFF samples were collected from Victoria and South Australia and one positive Little red flying fox (LRFF, Pteropus scapulatus) was collected from Western Australia. Immunohistochemistry confirmed the presence of henipavirus antigen, associated with an inflammatory lesion in cardiac blood vessels of one GHFF. Positive samples were sequenced and the complete genome was obtained from three samples. When compared to published HeV genomes, there was 84% sequence identity at the nucleotide level. Based on phylogenetic analyses, the newly detected HeV belongs to the HeV species but occupies a distinct lineage. We have therefore designated this virus HeV genotype 2 (HeV-g2). Attempts to isolate virus from PCR positive samples have not been successful.ConclusionsA novel HeV genotype (HeV-g2) has been identified in two flying fox species submitted from three states in Australia, indicating that the level of genetic diversity for HeV is broader than first recognised. Given its high genetic relatedness to HeV, HeV-g2 is a zoonotic pathogen.

Australian Bat Lyssavirus: Analysis of National Bat Surveillance Data from 2010 to 2016.

Australian bat lyssavirus (ABLV) was first described in 1996 and has been regularly detected in Australian bats since that time. While the virus does not cause population level impacts in bats and has minimal impacts on domestic animals, it does pose a public health risk. For this reason, bats are monitored for ABLV and a national dataset is collated and maintained by Wildlife Health Australia. The 2010–2016 dataset was analysed using logistic regression and time-series analysis to identify predictors of infection status in bats and the factors associated with human exposure to bats. In common with previous passive surveillance studies, we found that little red flying-foxes (Pteropus scapulatus) are more likely than other species to be infected with ABLV. In the four Australian mainland species of flying-fox, there are seasonal differences in infection risk that may be associated with reproductive cycles, with summer and autumn the seasons of greatest risk. The risk of human contact was also seasonal, with lower risk in winter. In line with other studies, we found that the circumstances in which the bat is encountered, such as exhibiting abnormal behaviour or being grounded, are risk factors for ABLV infection and human contact and should continue be key components of public health messaging. We also found evidence of biased recording of some types of information, which made interpretation of some findings more challenging. Strengthening of “One Health” linkages between public health and animal health services at the operational level could help overcome these biases in future, and greater harmonisation nationally would increase the value of the dataset.

Camp site habitat preferences of the little red flying-fox (

Urban flying-fox camps are a major source of human–wildlife conflict, producing noise, odour, vegetation damage, property damage, and concerns about disease. Although there is a significant demand in many communities for bat camps to be dispersed, there is limited information on how such dispersal can be conducted effectively. Determining the habitat characteristics flying-foxes use when selecting a camp site is key to understanding why they establish camps where they do and to where they might move if dispersed. We characterised little red flying-fox (LRFF) camp habitat at two spatial scales: floristics and vegetation structure at the local scale, and climatic and landscape characteristics at the broad scale. We found weak associations with local-scale tree and shrub height and cover, and stronger associations with increased Normalised Difference Vegetation Index (a measure of ‘greenness’) and decreased distance to nearest watercourse. These relationships were not strong enough to explain all variation in the model, suggesting that there are other factors, such as social cues, that could also influence camp site selection. Our results suggest that minor modifications to existing or proposed camp sites will be unlikely to repel or attract LRFFs, as other factors are likely to play key roles in the formation of camp sites for this species.

Optimisation of a pollen DNA metabarcoding method for diet analysis of flying-foxes (

Determining the diet of flying-foxes can increase understanding of how they function as pollinators and seed dispersers, as well as managing any negative impacts of large roosts. Traditional methods for diet analysis are time consuming, and not feasible to conduct for hundreds of animals. In this study, we optimised a method for diet analysis, based on DNA metabarcoding of environmental DNA (eDNA) from pollen and other plant parts in the faeces. We found that existing eDNA metabarcoding protocols are suitable, with the most useful results being obtained using a commercial food DNA extraction kit, and sequencing 350–450 base pairs of a DNA barcode from the internally transcribed spacer region (ITS2), with ~550 base pairs of the chloroplast rubisco large subunit (rbcL) as a secondary DNA barcode. A list of forage plants was generated for the little red flying-fox (Pteropus scapulatus), the black flying-fox (Pteropus alecto) and the spectacled flying-fox (Pteropus conspicillatus) from our collection sites across Queensland. The diets were determined to comprise predominantly Myrtaceae species, particularly those in the genera Eucalyptus, Melaleuca and Corymbia. With more plant genomes becoming publicly available in the future, there are likely to be further applications of eDNA methods in understanding the role of flying-foxes as pollinators and seed dispersers.

Owl survey of the Peel–Harvey Estuary in south-western Australia

Little is known of owls in south-western Australia compared with the owls of southern and eastern Australia. Surveys of forest owls in the south-west are almost completely lacking. This study sought to determine the abundance and detectability of owls immediately around the Peel–Harvey Estuary in south-western Australia. The southern boobook (Ninox boobook) and the masked owl (Tyto novaehollandiae) were the only owls detected (n = 23 and n = 1 respectively), although the nocturnal tawny frogmouth (Podargus strigoides) was detected from unelicited calls on three occasions. Southern boobooks were found to be common in this area though they are reported to be in decline in south-eastern and inland Australia. Their detectability was significantly greater in August (late winter) than at other times through unelicited calls; otherwise, there were no detections in winter. A variety of small mammals were detected during the surveys, including: a little red flying-fox (Pteropus scapulatus), a western ringtail possum (Pseudocheirus occidentalis), 19 southern brown bandicoots (Isoodon obesulus), 4 common brushtail possums (Trichosurus vulpecula), 21 rabbits (Oryctolagus cuniculus), a black rat (Rattus rattus), 2 red foxes (Vulpes vulpes) and 22 microbats.

Genomic characterization of a novel poxvirus from a flying fox: evidence for a new genus?

The carcass of an Australian little red flying fox (Pteropus scapulatus) which died following entrapment on a fence was submitted to the laboratory for Australian bat lyssavirus exclusion testing, which was negative. During post-mortem, multiple nodules were noted on the wing membranes, and therefore degenerate PCR primers targeting the poxvirus DNA polymerase gene were used to screen for poxviruses. The poxvirus PCR screen was positive and sequencing of the PCR product demonstrated very low, but significant, similarity with the DNA polymerase gene from members of the Poxviridae family. Next-generation sequencing of DNA extracted from the lesions returned a contig of 132 353 nucleotides (nt), which was further extended to produce a near full-length viral genome of 133 492 nt. Analysis of the genome revealed it to be AT-rich with inverted terminal repeats of at least 1314 nt and to contain 143 predicted genes. The genome contains a surprisingly large number (29) of genes not found in other poxviruses, one of which appears to be a homologue of the mammalian TNF-related apoptosis-inducing ligand (TRAIL) gene. Phylogenetic analysis indicates that the poxvirus described here is not closely related to any other poxvirus isolated from bats or other species, and that it likely should be placed in a new genus.

Trypanosoma teixeirae: A new species belonging to the T. cruzi clade causing trypanosomosis in an Australian little red flying fox (Pteropus scapulatus)

Little is known about the genetic diversity and pathogenicity of trypanosomes in Australian bats. Recently a novel trypanosome species was identified in an adult female little red flying fox (Pteropus scapulatus) with clinical and pathological evidence of trypanosomosis. The present study used morphology and molecular methods to demonstrate that this trypanosome is a distinct species and we propose the name Trypanosoma teixeirae sp. n. Morphological comparison showed that its circulating trypomastigotes were significantly different from those of Trypanosoma pteropi and Trypanosoma hipposideri, two species previously described from Australian bats. Genetic information was not available for T. pteropi and T. hipposideri but phylogenetic analyses at the 18S ribosomal RNA (rRNA) and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) loci indicated that T. teixeirae sp. n. was genetically distinct and clustered with other bat-derived trypanosome species within the Trypanosoma cruzi clade.

Novel paramyxoviruses in Australian flying-fox populations support host-virus co-evolution.

Understanding the diversity of henipaviruses and related viruses is important in determining the viral ecology within flying-fox populations and assessing the potential threat posed by these agents. This study sought to identify the abundance and diversity of previously unknown paramyxoviruses (UPVs) in Australian flying-fox species (Pteropus alecto, Pteropus scapulatus, Pteropus poliocephalus and Pteropus conspicillatus) and in the Christmas Island species Pteropus melanotus natalis. Using a degenerative reverse transcription-PCR specific for the L gene of known species of the genus Henipavirus and two closely related paramyxovirus genera Respirovirus and Morbillivirus, we identified an abundance and diversity of previously UPVs, with a representative 31 UPVs clustering in eight distinct groups (100 UPVs/495 samples). No new henipaviruses were identified. The findings were consistent with a hypothesis of co-evolution of paramyxoviruses and their flying-fox hosts. Quantification of the degree of co-speciation between host and virus (beyond the scope of this study) would strengthen this hypothesis.

Measuring physiological stress in Australian flying-fox populations.

Flying-foxes (pteropid bats) are the natural host of Hendra virus, a recently emerged zoonotic virus responsible for mortality or morbidity in horses and humans in Australia since 1994. Previous studies have suggested physiological and ecological risk factors for infection in flying-foxes, including physiological stress. However, little work has been done measuring and interpreting stress hormones in flying-foxes. Over a 12-month period, we collected pooled urine samples from underneath roosting flying-foxes, and urine and blood samples from captured individuals. Urine and plasma samples were assayed for cortisol using a commercially available enzyme immunoassay. We demonstrated a typical post-capture stress response in flying-foxes, established urine specific gravity as an attractive alternative to creatinine to correct urine concentration, and established population-level urinary cortisol ranges (and geometric means) for the four Australian species: Pteropus alecto 0.5–305.1 ng/mL (20.1 ng/mL); Pteropus conspicillatus 0.3–370.9 ng/mL (18.9 ng/mL); Pteropus poliocephalus 0.3–311.3 ng/mL (10.1 ng/mL); Pteropus scapulatus 5.2–205.4 ng/mL (40.7 ng/mL). Geometric means differed significantly except for P. alecto and P. conspicillatus. Our approach is methodologically robust, and has application both as a research or clinical tool for flying-foxes, and for other free-living colonial wildlife species.

Antibodies to Australian bat lyssavirus in an asymptomatic bat carer

[Extract] The recent fatal case of Australian bat lyssavirus (ABLV) in an 8-year-old boy in February 2013[1] as well as infections in horses in May 2013[2] has prompted us to write about an earlier non-fatal exposure. In August 1996, soon after the discovery of ABLV,[3] a serological survey of 14 bat carers in Townsville, North Queensland, detected antibodies (rapid fluorescent focus inhibition test (RFFIT) 0.48 international units (IU)/mL) in a 40-year-old male. As a volunteer bat carer for 10 years, mainly of black flying foxes (Pteropus alecto) and little red flying foxes (Pteropus scapulatus), he had received multiple bites and scratches. He had never received rabies vaccine or rabies immunoglobulin. He did not care for other Australian wildlife and had not visited rabies endemic countries.

The conservation status of New Zealand bats, 2009

The New Zealand Threat Classification System (NZTCS) is a national system used to assess the risk of extinction faced by New Zealand plants, animals and fungi. The system is specifically designed to be relevant to New Zealand's unusual ecological and geographic conditions. We undertook a re-evaluation of the status of seven bat taxa based on our knowledge of New Zealand bats using revised NZTCS criteria. Five taxa were listed as Threatened or At Risk: one as Nationally Critical (long-tailed bat Chalinolobus tuberculatus ‘South Island’), one as Nationally Endangered (southern lesser short-tailed bat Mystacina tuberculata tuberculata), two as Nationally Vulnerable (long-tailed bat ‘North Island’ and northern lesser short-tailed bat M. t. aupourica) and one as Declining (central lesser short-tailed bat M. t. rhyacobia). One taxon was assessed as Data Deficient (greater short-tailed bat M. robusta) and one (little red flying fox Pteropus scapulatus) as Vagrant. We suspect declines result primarily from predation and competition from introduced mammals, habitat degradation, and disturbance.

Broome virus, a new fusogenic Orthoreovirus species isolated from an Australian fruit bat

This report describes the discovery and characterization of a new fusogenic orthoreovirus, Broome virus (BroV), isolated from a little red flying-fox (Pteropus scapulatus). The BroV genome consists of 10 dsRNA segments, each having a 3' terminal pentanucleotide sequence conserved amongst all members of the genus Orthoreovirus, and a unique 5' terminal pentanucleotide sequence. The smallest genome segment is bicistronic and encodes two small nonstructural proteins, one of which is a novel fusion associated small transmembrane (FAST) protein responsible for syncytium formation, but no cell attachment protein. The low amino acid sequence identity between BroV proteins and those of other orthoreoviruses (13-50%), combined with phylogenetic analyses of structural and nonstructural proteins provide evidence to support the classification of BroV in a new sixth species group within the genus Orthoreovirus.

Reproduction and nutritional stress are risk factors for Hendra virus infection in little red flying foxes ( Pteropus scapulatus )

Hendra virus (HeV) is a lethal paramyxovirus which emerged in humans in 1994. Poor understanding of HeV dynamics in Pteropus spp. (flying fox or fruit bat) reservoir hosts has limited our ability to determine factors driving its emergence. We initiated a longitudinal field study of HeV in little red flying foxes (LRFF; Pteropus scapulatus) and examined individual and population risk factors for infection, to determine probable modes of intraspecific transmission. We also investigated whether seasonal changes in host behaviour, physiology and demography affect host-pathogen dynamics. Data showed that pregnant and lactating females had significantly higher risk of infection, which may explain previously observed temporal associations between HeV outbreaks and flying fox birthing periods. Age-specific seroprevalence curves generated from field data imply that HeV is transmitted horizontally via faeces, urine or saliva. Rapidly declining seroprevalence between two field seasons suggests that immunity wanes faster in LRFF than in other flying fox species, and highlights the potentially critical role of this species in interspecific viral persistence. The highest seroprevalence was observed when animals showed evidence of nutritional stress, suggesting that environmental processes that alter flying fox food sources, such as habitat loss and climate change, may increase HeV infection and transmission. These insights into the ecology of HeV in flying fox populations suggest causal links between anthropogenic environmental change and HeV emergence.

Optimized Architecture for Nutrition in the Avascular Retina of Megachiroptera

Investigations were undertaken to evaluate the unique choroidal vascular system of the Megachiroptera (fruit bats) and its possible significance for retinal nutrition. Fluorescein angiography was performed and documented on Pteropus poliocephalus. Vascular casts were made of the eye of Pteropus scapulatus. Histologic evaluation was performed on P. scapulatus. Results confirmed that each papilla has a vascular core, and a unique vascular system emanating from the optic disc. The histological appearance of the choroid and retina of P. scapulatus confirmed a vascular core to the papillae with a thin, but definite Bruch's membrane. Megachiroptera have a unique vascular system to supply nutrition to the retina consisting of capillary loops within a dense, uniform mosaic of choroidal projections or papillae, which permit the diffusion of metabolites to the retina and a heretofore undescribed vascular tuft emanating from the optic disc. We suggest that this vascular system provides nutrition by diffusion to a thick avascular retina, without any shadowing by vessels, and allows for nocturnal visual acuity and light-gathering capabilities.

Development and Evaluation of Real-Time Polymerase Chain Reaction Assays to Identify Mosquito (Diptera: Culicidae) Bloodmeals Originating from Native Australian Mammals

Real-time TaqMan polymerase chain reaction (PCR) assays were developed for the identification of mosquito (Diptera: Culicidae) bloodmeals originating from three groups of native Australian mammals. Primers and probes were designed to amplify a partial fragment of the cytochrome b gene of the agile wallaby, Macropus agilis (Gould); brushtail possum, Trichosurus vulpecula (Kerr); and the consensus sequence of the four species of Australian flying fox: Pteropus alecto Temminck, Pteropus conspicillatus Gould, Pteropus poliocephalus Temminck, and Pteropus scapulatus Peters. When tested on DNA extracted from whole tissue, each assay was shown to be specific for the vertebrate host that it was designed to identify. To evaluate the TaqMan assays, 137 field-collected blood-fed mosquitoes were analyzed, from which 128 (93.4%) were identified using one of the assays. Compared with other PCR-based techniques for bloodmeal identification, the TaqMan assays are sensitive, specific, and provide a rapid result without the need for post-PCR manipulation and visualization of products.

FLYING FOXES AS CARRIERS OF PATHOGENIC LEPTOSPIRA SPECIES

Recent serologic studies have identified flying foxes (Pteropus spp.) as carriers of leptospirosis; however, little is known about the role of flying foxes as carriers of pathogenic Leptospira spp. To determine if Australian Pteropus spp. are carriers of pathogenic Leptospira spp., TaqMan real-time polymerase chain reaction (PCR) was used to detect leptospiral DNA in kidney and urine specimens from four species of flying fox, including the spectacled flying fox (Pteropus conspicillatus), black flying fox (Pteropus alecto), grey-headed flying fox (Pteropus poliocephalus), and little red flying fox (Pteropus scapulatus). Of the 173 kidney samples tested, 19 (11%) were positive for leptospiral DNA. Positive individuals were detected in all four species; significant differences in prevalence were not detected between species, between species within the same geographic area, or between geographically separated samples from the same species. Of the 46 urine samples tested, 18 (39%) tested positive by PCR, confirming that flying foxes shed leptospires into the environment. The detection of leptospiral DNA in the kidneys and urine of flying foxes suggests that flying foxes are carriers of pathogenic Leptospira spp. No evidence collected in the present study, however, suggests that flying foxes pose a significant risk of leptospirosis to the wider community or that humans who are in regular, close contact with flying foxes are at risk for leptospirosis.

Collection, seminal characteristics and chilled storage of spermatozoa from three species of free-range flying fox ( Pteropus spp.)

This study reports observations on the collection and characteristics of semen from free-range populations of flying fox in Brisbane, Australia. Semen was successfully recovered by electroejaculation from 107 of 115 wild flying foxes ( Pteropus alecto, Pteropus poliocephalus and Pteropus scapulatus). A proportion of ejaculates collected from all three species contained seminal vesicle secretions, the incidence of which appeared related to breeding season. Ejaculate volume was small (5–160 μL), requiring a specialised collection vessel and immediate extension to avoid desiccation. Sperm morphological abnormalities and characteristics are described for the first time. In two species ( P. scapulatus and P. alecto), sperm quality varied with breeding season. Dilution in Tris–citrate–fructose buffer and subsequent incubation (37 °C) of Pteropus semen for 2–3 h appeared to have a negative impact on sperm motility and the percentage of sperm with intact plasma membranes and acrosomes and represents a concern for the potential development and use of assisted breeding technology in these species. Preliminary attempts to develop a short-term chilled preservation protocol for flying fox semen revealed that sperm viability (percentage motility and percentage live sperm with intact acrosomes) was significantly reduced after 102 h chilled storage at 5 °C; nevertheless, approximately 40% of the spermatozoa were still motile and contained intact acrosomes. Glycerol was neither protective nor detrimental to sperm survival during chilled storage. Microbial flora of the prepuce, urethra and semen of all species were isolated and their antibiotic susceptibility tested. Tetracycline, penicillin, ciprofloxacin, and ceftazidime were the most effective antibiotics in preventing growth of all identified bacteria; however, their effects on sperm survival were not investigated.

On the identity of flying-foxes, genus Pteropus (Mammalia: Chiroptera), from islands in the Torres Strait, Australia

Five flying-fox species (Pteropus scapulatus, P. alecto, P. conspicillatus, P. macrotis, and P. banakrisi) have been reported from islands in the Torres Strait, situated between northern Australia and southern Papua New Guinea. However, vouchered specimens demonstrate that Torres Strait records of the Large-eared flying-fox (Pteropus macrotis) actually reflect misidentifications of the Little Red flying-fox (P. scapulatus), and that the type series of Pteropus banakrisi Richards & Hall, 2002 (a newly-described species supposedly endemic to Moa Island) consists only of subadult individuals of the Black flying-fox (P. alecto). Only three flying-fox species are therefore known from the strait. These re-identifications underscore the importance of voucher specimens in biological investigations and have important implications for bat conservation in Australia. Pteropus macrotis is removed from the list of mammal species known from Australia, and banakrisi is placed in the synonymy of P. alecto.