Managing flying-foxes in a changing world
Flying-foxes (Pteropus spp.) are charismatic bats found across the tropical Old World and Oceania. They are among the most mobile mammals on earth by most measures, and their extreme mobility makes them key long-distance pollen and seed dispersers in forest ecosystems. However, flying-foxes are subject to a range of anthropogenic threats and information on the species' status and trends is limited, hampering conservation and management.
In the Lab of Animal Ecology, we run a range of projects on the conservation ecology of Australian flying-foxes to address current gaps in knowledge and to facilitate sound conservation management of these ecologically important species.
Over the last decade we have demonstrated that emerging technologies such as drone, radar and satellite remote-sensing, along with large-scale animal tracking, can radically improve flying-fox monitoring and the identification and documentation of threats. Improved monitoring of the spatiotemporal dynamics of flying-fox populations, along with improved knowledge of threats, will enable more effective, proactive conservation management of the species and their ecological services, across jurisdictional boundaries.
In the Lab of Animal Ecology, we run a range of projects on the conservation ecology of Australian flying-foxes to address current gaps in knowledge and to facilitate sound conservation management of these ecologically important species.
Over the last decade we have demonstrated that emerging technologies such as drone, radar and satellite remote-sensing, along with large-scale animal tracking, can radically improve flying-fox monitoring and the identification and documentation of threats. Improved monitoring of the spatiotemporal dynamics of flying-fox populations, along with improved knowledge of threats, will enable more effective, proactive conservation management of the species and their ecological services, across jurisdictional boundaries.
Figure 1. Australia's flying-fox species and their distributions. From left to right: the Christmas Island flying-fox (Pteropus natalis), spectacled flying-fox (P. conspicillatus), grey-headed flying-fox (P. poliocephalus), black flying-fox (P. alecto), and the little-red flying-fox (P. scapulatus). (Pictures: J. Welbergen)
Movement ecology
The extreme mobility of flying-foxes enables their successful exploitation of Australia’s ephemeral nectar resource environment; however, it also puts them in frequent conflict with humans. Thus, flying-foxes require a precarious balancing of conservation and community concerns, and identifying the mechanisms that underly their nomadic movements will have important implications for understanding flying-fox ecosystem services and for human vs. flying-fox conflict mitigation.
In the Lab of Animal Ecology, we link extensive tracking data on flying-fox movements to remote-sensed spatiotemporal dynamics of the nectar resources that drive those movements. Our ambitious, long-term goal here is to develop an integrated understanding of the nomadic movement dynamics of flying-fox populations across scales.
In the Lab of Animal Ecology, we link extensive tracking data on flying-fox movements to remote-sensed spatiotemporal dynamics of the nectar resources that drive those movements. Our ambitious, long-term goal here is to develop an integrated understanding of the nomadic movement dynamics of flying-fox populations across scales.
Emerging technologies for improved population monitoring
Reliable population monitoring is an essential prerequisite for sound wildlife management and conservation, especially for highly mobile species. However, traditional ground-based flying-fox monitoring is logistically complex and expensive, and lacks the precision required to respond quickly to population threats.
In the Lab of Animal Ecology, we have demonstrated that weather radar can be used to determine the numbers, directions and timing of flying-foxes emerging from their roosts. We have also shown that drone-acquired thermal imagery can be used to count flying-foxes at roosts semi-automatically and with very high accuracy and precision. We continue to develop and integrate the use of these emerging technologies to provide much-needed, reliable and cost-effective solutions to flying-fox population monitoring in Australia and abroad.
In the Lab of Animal Ecology, we have demonstrated that weather radar can be used to determine the numbers, directions and timing of flying-foxes emerging from their roosts. We have also shown that drone-acquired thermal imagery can be used to count flying-foxes at roosts semi-automatically and with very high accuracy and precision. We continue to develop and integrate the use of these emerging technologies to provide much-needed, reliable and cost-effective solutions to flying-fox population monitoring in Australia and abroad.
Threats and proactive conservation management
Flying-foxes face important emerging threats in Australia: mass die-offs from extreme heat events; range-wide destruction of foraging resources by bush fires; urbanisation and associated conflict with humans; and anticipated large-scale expansion of Australia's land-based wind energy sector.
In the Lab of Animal Ecology, we aim to understand and predict the impacts of these emerging threats on flying-fox populations, to support evidence-based, transboundary conservation and management policy, tailored to the unique movement ecologies of the species.
In the Lab of Animal Ecology, we aim to understand and predict the impacts of these emerging threats on flying-fox populations, to support evidence-based, transboundary conservation and management policy, tailored to the unique movement ecologies of the species.
Threatened, island-endemic flying-foxes
The Pteropus genus is predominantly an island taxon with all but three of the 66 species having all or part of their distribution on islands. While much of our research focuses on issues that are common to the flying-fox species in continental Australia, we are also running a long-term collaborative research program on remote Christmas Island, focussing specifically on the critically endangered Christmas Island flying-fox.
This research program is designed to assess and combat the decline of the Christmas Island flying-fox. The program is run with a range of stakeholder organisations, including Taronga Zoo and Parks Australia, with terrific on-island support, and we hope that it will provide a useful model for the conservation management of other small-island endemics throughout Australasia and the Pacific.
This research program is designed to assess and combat the decline of the Christmas Island flying-fox. The program is run with a range of stakeholder organisations, including Taronga Zoo and Parks Australia, with terrific on-island support, and we hope that it will provide a useful model for the conservation management of other small-island endemics throughout Australasia and the Pacific.
Relevant references from our lab
- TURBILL, C., WALKER, M., BOARDMAN, W., MARTIN, J., MCKEOWN, A., MEADE, J. & WELBERGEN, J. A. (2024) Torpor use in the wild by one of the world's largest bats. Proceedings of the Royal Society of London, Series B, doi: 10.1098/rspb.2024.1137
- DORRESTEIN, A., WESTCOTT, D., MARTIN, J.M., PHALEN, D., ROSE, K. & WELBERGEN, J.A., 2024. Bat mating systems—A review and recategorisation. Ecology and Evolution, 14(8):p.e70149.
- VOIGT, C. C., BERNARD*, E., HUANG*, J. C. C., FRICK*, W. F., KERBIRIOU*, C., MACEWAN*, K., MATHEWS*, F., RODRÍGUEZ-DURÁN*, A., SCHOLZ*, C., WEBALA*, P. W., WELBERGEN*, J. A., WHITBY* M. (2024). Towards solving the global green-green dilemma between wind energy production and bat conservation. BioScience, doi: 10.1093/biosci/biae02
- MO, M., TIMMISS, L.A., PEARSON, T., KERR, M.T., STEVES, S. AND WELBERGEN, J.A., (2024). "Normalising” flying-foxes: a bold vision for improving the public perceptions of our largest and most conspicuous bats. Australian Zoologist, doi: 10.7882/AZ.2024.001
- MO, M., MEADE, J., ROFF, A., TIMMISS, L.A., GIBSON, R. AND WELBERGEN, J.A. (2024). Impact assessment of the Australian 2019–20 megafires on roost sites of the vulnerable grey-headed flying-fox (Pteropus poliocephalus). Global Ecology and Conservation, doi: 10.1016/j.gecco.2024.e02822
- LLOYD-JONES, L. R., BRAVINGTON M. V., ARMSTRONG, K. N., LAWRENCE, E., FEUTRY, P., TODD, C. T., DORRESTEIN, A., WELBERGEN, J. A., MARTIN, J. M., ROSE, K., HALL, J., PHALEN, D. N., PETERS, I., BAYLIS, S. M., MACGREGOR, N. A. & WESTCOTT, D. A. (2023). Close-kin mark-recapture informs critically endangered terrestrial mammal status. Scientific Reports, doi: 10.1038/s41598-023-38639-z
- YABSLEY, S. H., MEADE, J., HIBBURT, T., MARTIN, J. M., BOARDMAN, W. S. J., NICOLLE, D., WALKER, M., TURBILL, C & WELBERGEN, J. A. (2022). Variety is the spice of life: flying-foxes exploit a variety of native and exotic food plants in an urban landscape mosaic. Frontiers in Ecology and Evolution, 10:907966
- PULSCHER, L. A., PEEL, A. J., ROSE, K., WELBERGEN, J. A., BAKER, M. L., BOYD V., LOW-CHOY S., EDSON D., TODD, C., DORRESTEIN A., HALL, J., TODD S., BRODER C. C., YAN, L., XU, K., PECK, G. R. & PHALEN, D. N. (2022) Serological evidence of a pararubulavirus and a betacoronavirus in the geographically isolated Christmas Island flying-fox (Pteropus natalis). Transboundary and Emerging Diseases, doi: 10.1111/tbed.14579
- MCCARTHY, E. D., MARTIN, J. M., BOER, M. M. & WELBERGEN (2022). Ground-based counting methods underestimate true numbers of a threatened colonial mammal: an evaluation using drone-based thermal surveys as a reference. Wildlife Research
- MO, M., MINEHAN, M., HACK, E., PLACE, V. & WELBERGEN J. A. (2022) A report of direct mortality in grey-headed flying-foxes (Pteropus poliocephalus) from the 2019-20 Australian megafires. Australian Mammalogy
- TODD, C. M., WESTCOTT, D.A., MARTIN, J. M., ROSE, K., MCKEOWN, A., HALL, J & WELBERGEN, J.A. (2022). Body-size dependent foraging strategies in the Christmas Island flying-fox: implications for seed and pollen dispersal within a threatened island ecosystem. Movement Ecology, 10:19
- MO, M., MEADE, J., PRICE J. C., MAISEY, J. C. & WELBERGEN J. A. (2022). Synchronous abortion events in the grey-headed flying-fox (Pteropus poliocephalus). Pacific Conservation Biology, doi: 10.1071/PC21060
- WELBERGEN, J. A. LAW, B. & COOPER, P. (2021) Bat research in Australasia – in memory of Les Hall (part 2). Australian Journal of Zoology, 68: 223-225
- LAW, B., WELBERGEN, J. A. & COOPER, P. (2021) Bat research in Australasia – in memory of Les Hall (part 1). Australian Journal of Zoology, 67: 241-242
- YABSLEY, S. H., MEADE, J., MARTIN, J. M., & WELBERGEN, J. A. (2021). Human-modified landscapes provide key foraging areas for a threatened flying mammal: The grey-headed flying-fox. Plos one, 16(11), e0259395.
- MEADE, J., MARTIN, J. M., & WELBERGEN, J. A. (2021). Fast food in the city? Nomadic flying-foxes commute less and hang around for longer in urban areas. Behavioral Ecology.
- MCCARTHY, E. D., MARTIN, J. M., BOER, M. M. & WELBERGEN (2021). Drone-based thermal remote sensing provides an effective new tool for monitoring the abundance of roosting fruit bats. Remote Sensing in Ecology and Conservation.
- RATNAYAKE, H. U., WELBERGEN J.A., VAN DER REE, R & KEARNEY, M. R. (2021) Variation in fur properties may explain differences in heat-related mortality among Australian flying-foxes. Australian Journal of Zoology, 68:285-295
- COX-WITTON, K., BAKER, M. L., EDSON, D., PEEL, A. J., WELBERGEN, J. A. & FIELD, H. (2021) Risk of SARS-CoV-2 transmission from humans to bats – An Australian assessment. One Health, 13: 100247
- MO, M., ROACHE, M., DAVIES, J., HOPPER, J., PITTY, H., FOSTER, N., ... & WELBERGEN, J. A. (2021). Estimating flying-fox mortality associated with abandonments of pups and extreme heat events during the austral summer of 2019–20. Pacific Conservation Biology
- PULSCHER, L. A., DIERENFELD, E. S., WELBERGEN, J. A., ROSE, K. A., & PHALEN, D. N. (2021). A comparison of nutritional value of native and alien food plants for a critically endangered island flying-fox. Plos One, 16: e0250857.
- TIMMISS, L. A., MARTIN, J. M., MURRAY, N. J., WELBERGEN, J. A., WESTCOTT, D., MCKEOWN, A., & KINGSFORD, R. T. (2021). Threatened but not conserved: flying-fox roosting and foraging habitat in Australia. Australian Journal of Zoology, 68:226–233
- PULSCHER, L. A., GRAY, R., MCQUILTY, R., ROSE, K., WELBERGEN, J., & PHALEN, D. N. (2020). Evidence of chronic cadmium exposure identified in the critically endangered Christmas Island flying-fox (Pteropus natalis). Science of The Total Environment, 144374.
- WELBERGEN, J. A., MEADE, J., FIELD, H., EDSON, D., McMICHAEL, L., SHOO, L. P., PRASZCZALEK, J., SMITH, C., MARTIN, J. (2020) Extreme mobility of the world's largest flying mammals creates key challenges for management and conservation. BMC Biology, 18:101
- PULSCHER, L. A., GRAY, R., MCQUILTY, R., ROSE, K., WELBERGEN, J. & PHALEN, D. N. 2020. Investigation into the utility of flying foxes as bioindicators for environmental metal pollution reveals evidence of diminished lead but significant cadmium exposure. Chemosphere, 254: 126839.
- LENTINI, P. & WELBERGEN, J. A. (2019). Managing tensions around urban flying‐fox roosts. Austral Ecology, 44 (2): 380-385. DOI: 10.1111/aec.12738 (HOT TOPIC)
- RATNAYAKE, H. U., KEARNEY, M, R., GOVEKAR, P., KAROLY, D. & WELBERGEN, J. A. (2019) Forecasting wildlife die-offs from extreme heat events. Animal Conservation, 22(4): 386-395. DOI: 10.1111/acv.12476
- MEADE, J., VAN DER REE, R., STEPANIAN, P. M., WESTCOTT, D. A. & WELBERGEN, J. A., 2019. Using weather radar to monitor the number, timing and directions of flying-foxes emerging from their roosts. Scientific Reports, 9(1):10222.
- TODD, C. M., WESTCOTT, D. A., ROSE, K., MARTIN, J. M., & WELBERGEN, J. A. (2018). Slow growth and delayed maturation in a Critically Endangered insular flying fox (Pteropus natalis). Journal of Mammalogy, 99(6), 1510-1521. DOI: doi.org/10.1093/jmammal/gyy11
- WELBERGEN, J. A. (2011) Fat males and fit females: sex differences in the seasonal patterns of body condition in grey-headed flying-foxes (Pteropus poliocephalus). Oecologia 165, 629-637
- WELBERGEN, J. A. (2010) Growth, bimaturation and sexual size dimorphism in wild gray-headed flying-foxes (Pteropus poliocephalus). Journal of Mammalogy 91, 38-47
- KLOSE, S., WELBERGEN, J. A., & KALKO, E. (2009) Testosterone is associated with harem maintenance ability in free-ranging grey-headed flying-foxes, Pteropus poliocephalus. Biology Letters 5, 758-761
- KLOSE, S., WELBERGEN, J., GOLDIZEN, A. & KALKO, E., (2009) Spatiotemporal vigilance architecture of an Australian flying-fox colony. Behavioral Ecology and Sociobiology 63, 371-380
- WELBERGEN, J. A. (2008) Variation in twilight predicts the duration of the evening emergence of fruit bats from a mixed-species roost. Animal Behaviour 75, 1543-1550
- WELBERGEN, J. A. (2006) Timing of the evening emergence from day roosts of the grey-headed flying-fox, Pteropus poliocephalus: the effects of predation risk, foraging needs, and social context. Behavioral Ecology and Sociobiology 60: 311-322
- WELBERGEN, J. A., KLOSE, S. M., MARKUS, N. & EBY, P. (2008) Climate change and the effects of temperature extremes on Australian flying-foxes. Proceedings of the Royal Society of London, Series B 275, 419-425
- WELBERGEN, J. A. (2005) The social organisation of the grey-headed flying-fox, Pteropus poliocephalus. Pp.265, PhD Thesis, University of Cambridge, UK. ***CLICK HERE FOR COPY***
- WELBERGEN, J. A. (2023). Black Flying-fox, Pteropus alecto. In ‘Strahan’s Mammals of Australia (4th edition)’. (Eds A. M. Baker, and I. C. Gynter) pp. 540–542. (Reed New Holland Publishers: Sydney). ISBN: 9781925546750
- WELBERGEN, J. A. (2023). Grey-headed Flying-fox, Pteropus poliocephalus. In ‘Strahan’s Mammals of Australia (4th edition)’. (Eds A. M. Baker, and I. C. Gynter) pp. 549–551. (Reed New Holland Publishers: Sydney). ISBN: 9781925546750
- WELBERGEN, J. A., SAUNDERS, L. & HALL, L. S. (2023). Little Red Flying-fox, Pteropus scapulatus. In ‘Strahan’s Mammals of Australia (4th edition)’. (Eds A. M. Baker, and I. C. Gynter) pp. 551–553. (Reed New Holland Publishers: Sydney). ISBN: 9781925546750
- TODD, C. M. & WELBERGEN, J. A. (2023). Christmas Island Flying-fox, Pteropus natalis. In ‘Strahan’s Mammals of Australia (4th edition)’. (Eds A. M. Baker, and I. C. Gynter) pp. 547–549. (Reed New Holland Publishers: Sydney). ISBN: 9781925546750
- EBY, P., ROBERTS, B., PENNAY, M. & WELBERGEN, J.A. 2021. Pteropus poliocephalus. The IUCN Red List of Threatened Species 2021: e.T18751A22085511. https://dx.doi.org/10.2305/IUCN.UK.2021-3.RLTS.T18751A22085511.en. Accessed on 01 January 2023.
- TODD, C.M., DORRESTEIN, A., PULSCHER, L.A. & WELBERGEN, J.A. 2021. Pteropus melanotus. The IUCN Red List of Threatened Species 2021: e.T18740A22082634. https://dx.doi.org/10.2305/IUCN.UK.2021-3.RLTS.T18740A22082634.en
- MARTIN, J, WALDIEN, D., NOVERA, J, WELBERGEN J. A., OEDIN, M., HANRAHAN, N., KINGSTON, T. and LAVERY, T. Pacific Island bats are utterly fascinating, yet under threat and overlooked. Meet 4 species. 25-8-2021
- WELBERGEN, J. A., PREECE, N. D. & VAN OOSTERZEE, P. Our laws failed these endangered flying-foxes at every turn. On Saturday, Cairns council will put another nail in the coffin. The Conversation, 1-7-2020
- LENTINI, P., PEEL, A., FIELD, H. & WELBERGEN, J. A. No, Aussie bats won’t give you COVID-19. We rely on them more than you think. The Conversation, 30-4-2020
- WELBERGEN, J.A. & ARMSTRONG, K. Why we shouldn’t be so quick to demonise bats. The Conversation, 22-12-17
- WELBERGEN, J.A. & EBY, P. Not in my backyard? How to live alongside flying-foxes in urban Australia. The Conversation, 27-5-16
- WELBERGEN J. A., BOOTH, C. and MARTIN, J. Killer climate: tens of thousands of flying foxes dead in a day. The Conversation, 24-2-14