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Vanderduys EP, Caley P, McKeown A, Martin JM, Pavey C, Westcott D. Population trends in the vulnerable Grey-headed flying-fox, Pteropus poliocephalus; results from a long-term, range-wide study. PLoS One 2024; 19:e0298530. [PMID: 38512935 PMCID: PMC10956843 DOI: 10.1371/journal.pone.0298530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 01/25/2024] [Indexed: 03/23/2024] Open
Abstract
Monitoring is necessary for the management of any threatened species if its predicament and status are to improve. Monitoring establishes baseline data for tracking trends in distribution and abundance and is a key tool for informing threatened species management. Across much of the Old World, bats in the genus Pteropus (Pteropodidae, Chiroptera) face significant threats from habitat loss, conflict with humans, and hunting. Despite conflict with humans and their threatened status, few Pteropus are being monitored. Often, this is because of difficulties associated with their high mobility, large and easily disturbed aggregations, and their use of unknown or remote habitat. Here we describe 10 years of results from the National Flying-fox Monitoring Program (NFFMP) for the grey-headed flying-fox, (Pteropus poliocephalus) in Australia. Range-wide quarterly surveys were conducted over a three-day period since November 2012 using standardized methods appropriate to conditions encountered at each roost. For our analysis of the population and its trend, we used a state-space model to account for the ecology of the grey-headed flying-fox and the errors associated with the surveying process. Despite the general perception that the species is in decline, our raw data and the modelled population trend suggest the grey-headed flying-fox population has remained stable during the NFFMP period, with the range also stable. These results indicate that the species' extreme mobility and broad diet bestow it with a high level of resilience to various disturbance events. Long-term, range-wide studies such as this one, are crucial for understanding relatively long-lived and highly nomadic species such as the grey-headed flying-fox. The outcomes of this study highlight the need for such systematic population monitoring of all threatened Pteropus species.
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Affiliation(s)
- Eric Peter Vanderduys
- Environment, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Brisbane, Queensland, Australia
| | - Peter Caley
- Data61, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Canberra, Australian Capital Territory, Australia
| | - Adam McKeown
- Environment, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Adelaide, South Australia, Australia
| | - John M. Martin
- Wildlife Services, Ecosure, Brisbane, Queensland, Australia
| | - Chris Pavey
- Environment, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Brisbane, Queensland, Australia
| | - David Westcott
- Environment, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Atherton, Queensland, Australia
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Barbosa AD, Egan S, Feng Y, Xiao L, Ryan U. How significant are bats as potential carriers of zoonotic Cryptosporidium and Giardia? CURRENT RESEARCH IN PARASITOLOGY & VECTOR-BORNE DISEASES 2023; 4:100155. [PMID: 38149267 PMCID: PMC10750029 DOI: 10.1016/j.crpvbd.2023.100155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 11/08/2023] [Accepted: 11/16/2023] [Indexed: 12/28/2023]
Abstract
Bats are known to harbour various pathogens and are increasingly recognised as potential reservoirs for zoonotic diseases. This paper reviews the genetic diversity and zoonotic potential of Cryptosporidium and Giardia in bats. The risk of zoonotic transmission of Cryptosporidium from bats to humans appears low, with bat-specific Cryptosporidium genotypes accounting for 91.5% of Cryptosporidium-positive samples genotyped from bats worldwide, and C. parvum and C. hominis accounting for 3.4% each of typed positives, respectively. To date, there have only been sporadic detections of Giardia in bats, with no genetic characterisation of the parasite to species or assemblage level. Therefore, the role bats play as reservoirs of zoonotic Giardia spp. is unknown. To mitigate potential risks of zoonotic transmission and their public health implications, comprehensive research on Cryptosporidium and Giardia in bats is imperative. Future studies should encompass additional locations across the globe and a broader spectrum of bat species, with a focus on those adapted to urban environments.
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Affiliation(s)
- Amanda D. Barbosa
- Harry Butler Institute, Vector- and Water-Borne Pathogen Research Group, Murdoch University, Murdoch, Western Australia 6150, Australia
- CAPES Foundation, Ministry of Education of Brazil, Brasilia, DF 70040-020, Brazil
| | - Siobhon Egan
- Harry Butler Institute, Vector- and Water-Borne Pathogen Research Group, Murdoch University, Murdoch, Western Australia 6150, Australia
| | - Yaoyu Feng
- Guangdong Laboratory for Lingnan Modern Agriculture, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Lihua Xiao
- Guangdong Laboratory for Lingnan Modern Agriculture, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Una Ryan
- Harry Butler Institute, Vector- and Water-Borne Pathogen Research Group, Murdoch University, Murdoch, Western Australia 6150, Australia
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Baranowski K, Bharti N. Habitat loss for black flying foxes and implications for Hendra virus. LANDSCAPE ECOLOGY 2023; 38:1605-1618. [PMID: 37229480 PMCID: PMC10073794 DOI: 10.1007/s10980-023-01642-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 03/17/2023] [Indexed: 05/27/2023]
Abstract
Context Environmental change impacts natural ecosystems and wildlife populations. In Australia, native forests have been heavily cleared and the local emergence of Hendra virus (HeV) has been linked to land-use change, winter habitat loss, and changing bat behavior. Objectives We quantified changes in landscape factors for black flying foxes (Pteropus alecto), a reservoir host of HeV, in sub-tropical Queensland, Australia from 2000-2020. We hypothesized that native winter habitat loss and native remnant forest loss were greatest in areas with the most human population growth. Methods We measured the spatiotemporal change in human population size and native 'remnant' woody vegetation extent. We assessed changes in the observed P. alecto population and native winter habitats in bioregions where P. alecto are observed roosting in winter. We assessed changes in the amount of remnant vegetation across bioregions and within 50 km foraging buffers around roosts. Results Human populations in these bioregions grew by 1.18 M people, mostly within 50 km foraging areas around roosts. Remnant forest extent decreased overall, but regrowth was observed when policy restricted vegetation clearing. Winter habitats were continuously lost across all spatial scales. Observed roost counts of P. alecto declined. Conclusion Native remnant forest loss and winter habitat loss were not directly linked to spatial human population growth. Rather, most remnant vegetation was cleared for indirect human use. We observed forest loss and regrowth in response to state land clearing policies. Expanded flying fox population surveys will help better understand how land-use change has impacted P. alecto distribution and Hendra virus spillover. Supplementary Information The online version contains supplementary material available at 10.1007/s10980-023-01642-w.
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Affiliation(s)
- Kelsee Baranowski
- Department of Biology, Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA USA
| | - Nita Bharti
- Department of Biology, Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA USA
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Sánchez CA, Penrose MT, Kessler MK, Becker DJ, McKeown A, Hannappel M, Boyd V, Camus MS, Padgett-Stewart T, Hunt BE, Graves AF, Peel AJ, Westcott DA, Rainwater TR, Chumchal MM, Cobb GP, Altizer S, Plowright RK, Boardman WSJ. Land use, season, and parasitism predict metal concentrations in Australian flying fox fur. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 841:156699. [PMID: 35710009 DOI: 10.1016/j.scitotenv.2022.156699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 05/19/2022] [Accepted: 06/10/2022] [Indexed: 06/15/2023]
Abstract
Urban-living wildlife can be exposed to metal contaminants dispersed into the environment through industrial, residential, and agricultural applications. Metal exposure carries lethal and sublethal consequences for animals; in particular, heavy metals (e.g. arsenic, lead, mercury) can damage organs and act as carcinogens. Many bat species reside and forage in human-modified habitats and could be exposed to contaminants in air, water, and food. We quantified metal concentrations in fur samples from three flying fox species (Pteropus fruit bats) captured at eight sites in eastern Australia. For subsets of bats, we assessed ectoparasite burden, haemoparasite infection, and viral infection, and performed white blood cell differential counts. We examined relationships among metal concentrations, environmental predictors (season, land use surrounding capture site), and individual predictors (species, sex, age, body condition, parasitism, neutrophil:lymphocyte ratio). As expected, bats captured at sites with greater human impact had higher metal loads. At one site with seasonal sampling, bats had higher metal concentrations in winter than in summer, possibly owing to changes in food availability and foraging. Relationships between ectoparasites and metal concentrations were mixed, suggesting multiple causal mechanisms. There was no association between overall metal load and neutrophil:lymphocyte ratio, but mercury concentrations were positively correlated with this ratio, which is associated with stress in other vertebrate taxa. Comparison of our findings to those of previous flying fox studies revealed potentially harmful levels of several metals; in particular, endangered spectacled flying foxes (P. conspicillatus) exhibited high concentrations of cadmium and lead. Because some bats harbor pathogens transmissible to humans and animals, future research should explore interactions between metal exposure, immunity, and infection to assess consequences for bat and human health.
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Affiliation(s)
- Cecilia A Sánchez
- Odum School of Ecology, University of Georgia, Athens, GA, USA; Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA.
| | - Michael T Penrose
- Department of Environmental Science, Baylor University, Waco, TX, USA
| | | | - Daniel J Becker
- Department of Biology, University of Oklahoma, Norman, OK, USA
| | | | | | - Victoria Boyd
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Health and Biosecurity Business Unit, The Australian Centre for Disease Preparedness (ACDP), Geelong, VIC, Australia
| | - Melinda S Camus
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Ticha Padgett-Stewart
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Brooklin E Hunt
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Amelia F Graves
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Alison J Peel
- Centre for Planetary Health and Food Security, Griffith University, Nathan, QLD, Australia
| | | | - Thomas R Rainwater
- Tom Yawkey Wildlife Center and Belle W. Baruch Institute of Coastal Ecology and Forest Science, Clemson University, Georgetown, SC, USA
| | | | - George P Cobb
- Department of Environmental Science, Baylor University, Waco, TX, USA
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA, USA; Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA
| | - Raina K Plowright
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Wayne S J Boardman
- School of Animal and Veterinary Sciences, University of Adelaide, SA, Australia
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Yabsley SH, Meade J, Hibburt TD, Martin JM, Boardman WSJ, Nicolle D, Walker MJ, Turbill C, Welbergen JA. Variety is the spice of life: Flying-foxes exploit a variety of native and exotic food plants in an urban landscape mosaic. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.907966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Generally, urbanization is a major threat to biodiversity; however, urban areas also provide habitats that some species can exploit. Flying-foxes (Pteropus spp.) are becoming increasingly urbanized; which is thought to be a result of increased availability and temporal stability of urban food resources, diminished natural food resources, or both. Previous research has shown that urban-roosting grey-headed flying-foxes (Pteropus poliocephalus) preferentially forage in human-modified landscapes. However, which land-use areas and food plants support its presence in urban areas is unknown. We tracked nine P. poliocephalus roosting in Adelaide, South Australia, between December 2019 and May 2020, using global positioning systems (GPS), to investigate how individuals used the urban landscape mosaic for feeding. The most frequently visited land-use category was “residential” (40% of fixes) followed by “road-side,” “reserves” and “primary production” (13–14% each). However, “reserves” were visited four times more frequently than expected from their areal availability, followed by the “residential” and “road-side” categories that were visited approximately twice more than expected each; in contrast, the “primary production” category was visited approximately five times less than expected. These results suggest that while residential areas provide most foraging resources supporting Adelaide’s flying-fox population, reserves contain foraging resources that are particularly attractive to P. poliocephalus. Primary production land was relatively less utilized, presumably because it contains few food resources. Throughout, flying-foxes visited an eclectic mixture of diet plants (49 unique species), with a majority of feeding fixes (63%) to locally indigenous Australian native species; however, in residential areas 53% of feeding visits were to non-locally indigenous species, vs only 13% in reserves. Flowering and fruiting phenology records of the food plants visited further indicated that non-locally indigenous species increase the temporal availability of foraging resources for P. poliocephalus in urban Adelaide. Our findings demonstrate the importance of residential areas for urban-roosting P. poliocephalus, and suggest that the anthropogenic mixture of food resources available in the urban landscape mosaic supports the species’ year-round presence in urban areas. Our results further highlight the importance of conserving natural habitats within the urban landscape mosaic, and stress the need for accounting for wildlife responses to urban greening initiatives.
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