Long-tailed Bat Research Articles

Virome analysis of New Zealand's bats reveals cross-species viral transmission among the Coronaviridae.

The lesser short-tailed bat (Mystacina tuberculata) and the long-tailed bat (Chalinolobus tuberculatus) are Aotearoa New Zealand's only native extant terrestrial mammals and are believed to have migrated from Australia. Long-tailed bats arrived in New Zealand an estimated two million years ago and are closely related to other Australian bat species. Lesser short-tailed bats, in contrast, are the only extant species within the Mystacinidae and are estimated to have been living in isolation in New Zealand for the past 16-18 million years. Throughout this period of isolation, lesser short-tailed bats have become one of the most terrestrial bats in the world. Through a metatranscriptomic analysis of guano samples from eight locations across New Zealand, we aimed to characterise the viromes of New Zealand's bats and determine whether viruses have jumped between these species over the past two million years. High viral richness was observed among long-tailed bats with viruses spanning seven different viral families. In contrast, no bat-specific viruses were identified in lesser short-tailed bats. Both bat species harboured an abundance of likely dietary- and environment-associated viruses. We also identified alphacoronaviruses in long-tailed bat guano that had previously been identified in lesser short-tailed bats, suggesting that these viruses had jumped the species barrier after long-tailed bats migrated to New Zealand. Of note, an alphacoronavirus species discovered here possessed a complete genome of only 22,416 nucleotides with entire deletions or truncations of several non-structural proteins, thereby representing what may be the shortest genome within the Coronaviridae identified to date. Overall, this study has revealed a diverse range of novel viruses harboured by New Zealand's only native terrestrial mammals, in turn expanding our understanding of bat viral dynamics and evolution globally.

Influence of weather on long-tailed bat detection in a North Island exotic forest

Influence of weather on long-tailed bat detection in a North Island exotic forest

Occupation of artificial roosts by long-tailed bats (Chalinolobus tuberculatus) in Hamilton City, New Zealand

ABSTRACT Deforestation, increasing urban development and associated infrastructure have resulted in widespread loss of roosting habitat for New Zealand’s long-tailed bat (Chalinolobus tuberculatus, pekapeka-tou-roa). As a result, artificial roosts are increasingly proposed as a short to medium-term mitigation measure, despite the absence of specific protocols for the installation, maintenance, and suitability for New Zealand bats. As of 2021, more than 110 artificial roosts had been installed in urban parks within Hamilton City, New Zealand. To determine their uptake and suitability for long-tailed bats, 74 Kent style roosts of varying ages were monitored for 1 year, with 24 (32%) roosts observed occupied by long-tailed bats. Occupation was generally infrequent, with no clear seasonal pattern or specific areas of occupation. However, two older roosts were consistently occupied, with numbers notably increasing during the summer maternity season. Distance to stand edge was the only factor that could be used to predict occupation, with logistic regression indicating that long-tailed bats may prefer roosts in less exposed areas with stable microclimates, within tree stands or sheltered landscape features. Future artificial roost installations should site roosts away from the stand edge in sheltered locations, ideally near natural or already occupied roosts to facilitate discovery and uptake.

Using faecal DNA metabarcoding to determine the diet of the long-tailed bat, Chalinolobus tuberculatus

ABSTRACT Dietary analysis of nocturnal aerial insectivores such as bats is not possible by direct visual observation of predation, therefore diet is traditionally determined by analysing dietary remains in scats. Analysing DNA in scats through metabarcoding can reveal dietary items not preserved in faeces but also resolve dietary preferences to species level. DNA metabarcoding analysis of scats collected from six individual long-tailed bats (Chalinolobus tuberculatus) from Whirinaki Forest Park revealed a predominance of aquatic insects (Ephemeroptera and Trichoptera) and small-bodied moths (Lepidoptera). This contrasts with earlier studies of faecal remains in this species which revealed a strong preference for Dipterans and Coleopterans. The use of DNA metabarcoding may provide a better understanding of diets, as soft-bodied insects can be detected even when not apparent in physical examinations of scat, and thus will allow for more robust comparison of differences in diets between populations and seasons. The application of DNA metabarcoding is a simple but high-resolution tool to allow further study on dietary preference in this endangered species.

More Traffic, Less Bat Activity: The Relationship between Overnight Traffic Volumes and Chalinolobus tuberculatus Activity along New Zealand Highways

Despite a growing body of evidence worldwide that bats are affected by roads, there has been little research into the effects of traffic volume on bat activity. In New Zealand, there is considerable uncertainty over whether, or to what extent, roads affect New Zealand's endemic bat populations, and this has resulted in uncertainty during the planning and consent phases of road development projects. This research investigated whether Chalinolobus tuberculatus (long-tailed bat) activity correlates with night-time traffic volume on New Zealand's highways. Bat activity was monitored at 57 traffic monitoring sites throughout New Zealand using pairs of bat detectors, with one placed beside the highway (highway) and one placed ≥ 200 metres from the highway (distant). Generalised linear mixed effects models were used to investigate the relationship between bat detections, position in relation to the highway, and various measures of traffic volume. The model that best explained the variation in bat detections was the interaction effect between bat detector position (highway, distant) and night-time traffic volume (volume). Outputs from this model show a negative relationship between bat activity and night-time traffic volume for highway bat detector units, while distant bat detector units had no discernible relationship with night-time traffic volume. These results indicate that night-time traffic volume affects the use of roads by bats, i.e. when overnight traffic increased, the probability of detecting bats decreased. Whether or to what extent this will affect the long-term viability of New Zealand's C. tuberculatus populations is a high priority for further investigation.

The first record of the spinturnicid mite Spinturnix kolenatii Oudemans, 1910 (Mesostigmata: Gamasina: Spinturnicidae) from the long-tailed serotine bat Eptesicus hottentotus A. Smith, 1833 (Chiroptera: Vespertilionidae) in Africa

ABSTRACTThree individuals of a spinturnicid mite resembling, Spinturnix kolenatii, are reported from the long-tailed serotine bat, Eptesicus hottentotus A. Smith, 1833 (Chiroptera: Vespertilionidae), caught in the Kunene Region of Namibia (Southern Africa). This is the first report of S. kolenatii in Africa, significantly expanding the geographical distribution range of this ectoparasite.

Controlling invasive predators enhances the long-term survival of endangered New Zealand long-tailed bats (Chalinolobus tuberculatus): Implications for conservation of bats on oceanic islands

Invasive mammalian predators pose one of the greatest threats to biodiversity globally, particularly on oceanic islands. However, little is known about the impacts of these invasive predators on bats (Chiroptera), one of the most specious mammal groups, and one of the most widespread groups of mammals threatened on oceanic islands (>200 spp.). Nearly 50% of the world's threatened bats are island endemics and because they are often the only native mammals on islands, they fulfil important ecological roles such as pollination and seed dispersal. Long-tailed bats (Chalinolobus tuberculatus) are critically endangered because of predation by exotic mammals, particularly ship rats (Rattus rattus), introduced by humans to the island archipelago of New Zealand. We monitored the survival of bats in three colonies in temperate rainforest in Fiordland over 22years. Since 2009, we controlled predators during irruption phases and compared survival of bats in previously untreated areas with survival in forest blocks treated using rodenticides deployed in bait stations. Survival was estimated using multi-state mark-recapture models in Program Mark 7.0 with >15,000 bats tagged. Survival was primarily dependent on year and age of bats, although seedfall intensity of the dominant canopy tree and predator management was also influential. Survival in long-tailed bats was as high as, or higher, than figures for bats generally in years with low predator numbers or predator control. Survival was markedly higher in treatment years when predators were managed (0.82 compared to 0.55). Population modelling indicated managed colonies will increase (λ>1.05) whereas unmanaged colonies will decline (λ=0.89−0.98) under scenarios that reflect increased frequency of beech mast and predator irruptions. Thus, effective predator control is essential for recovering long-tailed bat populations. Warming temperatures indicate that predator irruptions are becoming more frequent, which would require more predator control in the future than at present if declines in bat populations are to be reversed. These results are relevant to the conservation of threatened bats on oceanic islands, given the abundance of exotic mammalian predators, particularly ship rats, on them.

Phylogeographic-based conservation implications for the New Zealand long-tailed bat, (Chalinolobus tuberculatus): identification of a single ESU and a candidate population for genetic rescue

The New Zealand long-tailed bat (Chalinolobus tuberculatus) is an endemic species threatened with extinction. Since the arrival of humans, massive deforestation has occurred and invasive mammalian predators were introduced. As a result, C. tuberculatus’ distribution shrank dramatically and became fragmented. To aid the management of the remaining populations, two Evolutionary Significant Units (ESUs) were designated: one on each of New Zealand’s main islands. We utilised mitochondrial sequence data (cytb, 703 bp) and 10 nuclear DNA microsatellite loci to reconstruct the demographic history of this species, to characterise the level of genetic diversity in remaining populations, and to assess the current connectivity between them. Our results indicate that the North Island, with the highest genetic diversity, served as a glacial refuge, with a loss of diversity following the path recolonization to the south of the South Island. However, our data are also consistent with continued, or at least very recent, genetic exchange between colonies across the species distribution. The only exception is the Hanging Rock colony on the east coast of the South Island, which appears to be isolated. Thus, there was no support for the previously designated ESUs. Signatures of past population declines were found in three colonies, the most extreme of which was found in Hanging Rock. Consequently, we recommend that it be genetically rescued via translocation from a donor population. In general, future management priorities should treat Chalinolobus tuberculatus as a single unit, focusing on maintaining connectivity between remaining populations, together with continued roost protection and pest control.

Genetic diversity is maintained in the endangered New Zealand long-tailed bat (Chalinolobus tuberculatus) despite a closed social structure and regular population crashes

Maintaining the genetic diversity of populations is important in conservation because it strongly influences the ability to adapt to changing environments. We characterised the genetic structure of the endemic and endangered New Zealand (NZ) long-tailed bat (Chalinolobus tuberculatus) in two valleys in Fiordland, NZ. Fiordland is one of the last strongholds of the species, which has drastically declined throughout NZ. C. tuberculatus has suffered from recent habitat fragmentation and episodic predation by exotic mammals over the last 150 years. Gene flow and structuring were measured using nine nuclear microsatellite loci. In addition, the hyper-variable domain HVI of the mitochondrial control region was sequenced to analyse population structure at the maternal level. Our results show that the nine colonies studied have retained high genetic diversity, with moderate signs of genetic bottlenecks. Furthermore, low F ST and F IS values indicated that all colonies are still connected by gene flow and do not show signs of inbreeding. Substantial gene flow among colonies was also demonstrated by Bayesian clustering and PCA analysis. At the mitochondrial level, substantial differentiation between colonies has resulted from strong natal philopatry in females. Overall, our results indicate that genetic diversity is maintained in the Fiordland population of C. tuberculatus despite regular population crashes and habitat fragmentation. Management should ensure that remaining habitat linkages are preserved and further predator-induced population bottlenecks are prevented so that current genetic diversity is maintained in the long-term.

Discovery of novel virus sequences in an isolated and threatened bat species, the New Zealand lesser short-tailed bat (Mystacina tuberculata)

Bats harbour a diverse array of viruses, including significant human pathogens. Extensive metagenomic studies of material from bats, in particular guano, have revealed a large number of novel or divergent viral taxa that were previously unknown. New Zealand has only two extant indigenous terrestrial mammals, which are both bats, Mystacina tuberculata (the lesser short-tailed bat) and Chalinolobus tuberculatus (the long-tailed bat). Until the human introduction of exotic mammals, these species had been isolated from all other terrestrial mammals for over 1 million years (potentially over 16 million years for M. tuberculata). Four bat guano samples were collected from M. tuberculata roosts on the isolated offshore island of Whenua hou (Codfish Island) in New Zealand. Metagenomic analysis revealed that this species still hosts a plethora of divergent viruses. Whilst the majority of viruses detected were likely to be of dietary origin, some putative vertebrate virus sequences were identified. Papillomavirus, polyomavirus, calicivirus and hepevirus were found in the metagenomic data and subsequently confirmed using independent PCR assays and sequencing. The new hepevirus and calicivirus sequences may represent new genera within these viral families. Our findings may provide an insight into the origins of viral families, given their detection in an isolated host species.

Temporal and spatial distribution and habitat associations of an urban population of New Zealand long-tailed bats (Chalinolobus tuberculatus)

Two ultrasound survey methods were used to determine the presence and activity patterns of New Zealand long-tailed bats (Chalinolobus tuberculatus) in the city of Hamilton. First, 13 monthly surveys conducted at 18 green spaces found C. tuberculatus in only one urban forest reserve, Hammond Bush, where they were found consistently throughout the year. Bat activity was strongly related to temperature. Second, twice-yearly citywide surveys conducted over 2 years determined the distribution and habitat associations of C. tuberculatus. Bats were found only in the southern part of the city and were strongly associated with the Waikato River. Bat activity was negatively correlated with housing and street light density and positively correlated with topographical complexity. In Hamilton, topographical complexity indicates the presence of gullies. Gullies probably provide foraging and roosting opportunities and connect the river to distant forest patches. These results suggest that urban habitats can be useful for bats if gullies can link these to distant habitat fragments.

Effects of clear-fell harvest on bat home range.

We investigated effects of roost loss due to clear-fell harvest on bat home range. The study took place in plantation forest, inhabited by the New Zealand long-tailed bat (Chalinolobus tuberculatus), in which trees are harvested between the ages 26–32 years. We determined home ranges by radiotracking different bats in areas that had and had not been recently clear-fell harvested. Home ranges were smaller in areas that had been harvested. Adult male bats selected 20–25 year old stands within home ranges before and after harvest. Males selected edges with open unplanted areas when harvest had not occurred but no longer selected these at proportions greater than their availability post harvest, probably because they were then readily available. This is the first radiotracking study to demonstrate a change in home range size and selection concomitant with felling of large areas of plantation forest, and thus quantify negative effects of forestry operations on this speciose group. The use of smaller home ranges post-harvest may reflect smaller colony sizes and lower roost availability, both of which may increase isolation of colonies and vulnerability to local extinction.

Spatial and temporal variation in long-tailed bat echolocation activity in a New Zealand city

Knowing when and where animals are active improves wildlife management. We monitored variation in long-tailed bat (Chalinolobus tuberculatus) echolocation activity at two sites (one urban, one rural) in Hamilton, New Zealand, across different nights, seasons, microhabitats and environmental conditions. Activity peaked between the first and third hours after sunset. Activity was higher during spring and summer compared with winter. At the rural site, more passes were recorded at 4–6 m than at 15–30 m. More bat passes were recorded in microhabitats with water. Temperature correlated positively with activity at the rural site only. To maximize detections we recommend that bats be monitored: (1) during warmer months (spring/summer), (2) on warm nights (≥ 7°C), 3) at lower heights (≤ 6 m from the ground), and (4) in open edge and forested microhabitats with water. Recommendations should enable practitioners to focus resources so that bats are effectively detected in urban and rural habitats.

Do Long-Tailed Bats Alter Their Evening Activity in Response to Aircraft Noise?

Human-generated noise may alter animal activity patterns and mask vocal signals. We used field-based observations and a playback experiment to investigate whether aircraft activity and noise alter the evening activity of New Zealand long-tailed bats (Chalinolobus tuberculatus) a cryptic threatened species. Low-altitude aircraft activity temporally overlapped bat activity near the runway of an international airport, but was unlikely to mask echolocation pulses as aircraft noise was most intense at ≤ 10 kHz. There was no statistically significant difference in mean bat activity during and after overflights compared with pre-aircraft activity. The experiment revealed that playback stimuli (aircraft passes and two controls: silent tracks and blackbird (Turdus merula) calls) differed in their effect on bat activity at two sites, one with low and one with high aircraft activity. Simulated aircraft noise and silent tracks reduced bat activity when compared with blackbird calls (P < 0.05). Bats may have found it ...

Sex-Specific Roost Selection by Bats in Clearfell Harvested Plantation Forest: Improved Knowledge Advises Management

To maximize energetic savings, female bats often roost communally whilst pregnant or with non-volant dependents, whereas male bats more often roost alone; however, differences in selection of roosts by sex have not often been investigated. Better understanding of female colony locations could focus management to protect the majority of bats. New Zealand’s long-tailed bat (Chalinolobus tuberculatus) roost in exotic plantation forest, where sex-specific roost selection has not been investigated, and therefore such management is not possible. We investigated sex-specific roost selection by long-tailed bats for the first time. Roosts and paired nonroosts were characterized testing predictions that males and females select roosts that differ from non-roosts, and males and females select different roosts. Females and males chose Pinus radiata roosts that differed from non-roost trees. Results suggest each sex chose roosts that maximized energetic savings. Female bats used roosts closer to water sources, that warmed earlier in the day, which allowed maintenance of high temperatures. Males appeared to choose roosts that allowed torpor use for long periods of the day. Males may be less selective with their roost locations than females, as they roosted further from water sources. This could allow persistence of male bats in marginal habitat. As all female long-tailed bats chose roosts within 150 m of waterways, management to protect bats could be focused here. To protect bats least able to escape when roosts are harvested, harvest of forest stands selected by female bats as roost sites should be planned when bats are not heavily pregnant nor have non-volant dependents.

Bat colony size reduction coincides with clear-fell harvest operations and high rates of roost loss in plantation forest

Clear-fell harvest of forest concerns many wildlife biologists because of loss of vital resources such as roosts or nests, and effects on population viability. However, actual impact has not been quantified. Using New Zealand long-tailed bats (Chalinolobus tuberculatus) as a model species we investigated impacts of clear-fell logging on bats in plantation forest. C. tuberculatus roost within the oldest stands in plantation forest so it was likely roost availability would decrease as harvest operations occurred. We predicted that post-harvest: (1) roosting range sizes would be smaller, (2) fewer roosts would be used, and (3) colony size would be smaller. We captured and radiotracked C. tuberculatus to day-roosts in Kinleith Forest, an exotic plantation forest, over three southern hemisphere summers (Season 1 October 2006–March 2007; Season 2 November 2007–March 2008; and Season 3 November 2008–March 2009). Individual roosting ranges (100% MCPs) post harvest were smaller than those in areas that had not been harvested, and declined in area during the 3 years. Following harvest, bats used fewer roosts than those in areas that had not been harvested. Over 3 years 20.7% of known roosts were lost: 14.5% due to forestry operations and 6.2% due to natural tree fall. Median colony size was 4.0 bats (IQR = 2.0–8.0) and declined during the study, probably because of locally high levels of roost loss. Post harvest colonies were smaller than colonies in areas that had not been harvested. Together, these results suggest the impact of clear-fell harvest on long-tailed bat populations is negative.

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.

The importance of exotic plantation forest for the New Zealand long-tailed bat (Chalinolobus tuberculatus)

Environmental certification schemes have stimulated increasing interest in biodiversity and its management within exotic plantation forests. These schemes expect management to be scientifically-based, even though little is known about how often, or which, native species use exotic plantation forests. Greater knowledge of the ecology of native species within exotic plantation forests is required to advise management and reduce risks to native species, particularly those that are rare, such as the New Zealand long-tailed bat (Chalinolobus tuberculatus). Long-tailed bats use exotic plantation forests throughout New Zealand but need protection from the impacts of forest management, and particularly clear-fell harvest, that is achievable only through a better understanding of their biology. The consequences of the current reduced re-planting, and the conversion of plantation forests into pasture resulting in smaller forested areas, should not be ignored because they may be associated with reductions in long-tailed bat populations. We review the current knowledge of long-tailed bats' use of exotic plantation forests, and report for the first time which exotic plantations long-tailed bats are known to use. We make recommendations for the design of monitoring programmes to detect long-tailed bats within plantation forests, and for research into the effects of forest management, especially logging, and comment on the likely impacts of reductions in forested areas on long-tailed bats.

Microsatellite markers for the endemic New Zealand long‐tailed bat (Chalinolobus tuberculatus)

The New Zealand long-tailed bat (Chalinolobus tuberculatus) is an endangered species which is now absent from many habitats where they were previously observed. However, population genetics studies have been hampered by the lack of reliable genetic markers. We have developed 13 microsatellite markers, and at least eight of these are suitable for population studies. Nine of these markers also cross-react with the closely related Australian species C. gouldii. These markers may prove of general utility in the genus Chalinolobus.

Predictive modelling and ground validation of the spatial distribution of the New Zealand long-tailed bat ( Chalinolobus tuberculatus)

The use of predictive models is continually increasing, but few models are subsequently field-checked and evaluated. This study evaluates the statistical strength and usefulness for conservation purposes of a predictive habitat use model developed for Chalinolobus tuberculatus, a threatened microchiropteran bat species found in the temperate rainforests of New Zealand. The relationship between various environmental variables and the presence/absence of the species was investigated using generalised linear modelling. The model developed was coupled with GIS data to develop maps of predicted occurrence within the West Coast region of New Zealand’s South Island. It was found that distance to forest boundary, slope, presence of Nothofagus, general land cover, variability in mean annual solar radiation, and mean ambient winter minimum temperature were significantly associated with the occurrence of the species. Evaluation of the statistical strength of the distribution model with independent data of species’ occurrence collected at 152 sites found that the C. tuberculatus model showed a moderate ability to predict both species presence and absence ( τ( b) coefficient = 0.37). The field detection rate (0.45) using this model was significantly higher than that of historical surveys (0.12). The value of the species habitat model and the need to evaluate its utility in the development of conservation strategies is discussed.