Flying-fox movement ecology

How and why animals move across the planet has fascinated humankind since time immemorial. However, until recently, progress in movement research has been slow due to technological limitations and a lack of consistent methodology. Current research focuses on understanding the underlying causes of movement patterns and their ecological and evolutionary consequences. Such studies are key for our fundamentla understanding of animal movement as well as for managing our biodiversity under anthropogenic environmental change.

Flying-foxes are charismatic bats found across the Old World and Australia. They are the most mobile mammals on earth by most measures, and ideal models for studying movement across a wide range of spatiotemporal scales. Flying-fox movements range from small relocations within colonies and foraging sites, to nightly foraging trips of up to 80 km, to long-distance nomadism covering thousands of kilometres across up to 16 degrees of latitude in a single year.

Their extreme mobility makes flying-foxes key long-distance pollen and seed dispersers in Australia’s fragmented forest ecosystems, and enables their successful exploitation of the unpredictable resource environment of this country. However, their mobility also facilitates transmission of disease and often brings them in conflict with humans, and so they require a precarious balancing of conservation and management concern.

Understanding how and why flying-foxes move across different spatiotemporal scales is crucial for the management of the species, the habitats in which they live, and the trajectory of new emerging diseases. Recent advances in tracking technology and remote-sensing, makes it possible - for the first time - to investigate movement from local to continental scales in a single animal system.

Nomadic movements of two adult female grey-headed flying-foxes, tracked over a period of five years (Welbergen et al. 2020).

Aims & Objectives

THIS RESEARCH IS TO DEVELOP A MECHANISTIC UNDERSTANDING OF THE MOVEMENT ECOLOGY OF FLYING-FOXES, FROM LOCAL TO CONTINENTAL SCALES.

To make this ambitious aim tractable, our research program will focus on the following two areas of research:

How do flying-foxes navigate?
What are the drivers of flying-fox movements?

With this project we address key issues in the field of movement research, and provide much-needed scientific underpinnings for policy and management of Australia's flying-foxes and other mobile species.

Our approach is guided by the emerging paradigm of ‘movement ecology’ that focuses on identifying behaviour from tracking data and revealing the mechanisms that drive patterns of movement.

Our methodology involves innovative experimental manipulation, designed to determine how flying-foxes navigate, and data from cutting edge GPS/biotelemetry technology, satellite telemetry, and Doppler radar. Combined with the latest analytical techniques, these will enable us to determine the intrinsic (i.e. physiological) and environmental factors that govern flying-fox movements. We are in the unique position that we already have at our disposal the biotelemetry technology, and the extensive GPS, satellite and Doppler radar data required to successfully complete this project.

Fabulously insightful overview of our lab's work by The Guardian's First Dog on the Moon!

Research Team

Our Research Program brings together a multi-institutional team comprising the following people:

Prof Justin Welbergen - Hawkesbury Institute for the Environment (Western Sydney University)
Dr Christopher Turbill - Hawkesbury Institute for the Environment (Western Sydney University)
Dr Jessica Meade - Hawkesbury Institute for the Environment (Western Sydney University)
Dr David Westcott - CSIRO
Adam McKeown - CSIRO
Dr John Martin - Taronga Conservation Society Australia

Student Projects

Melissa Walker - PhD Candidate (Western Sydney University; supervisors: Dr Christopher Turbill, Dr Jessica Meade, Prof Justin Welbergen). Topic: Flying-fox phyisology and energetics
Eliane McCarthy - MRes student (University of Western Sydney; supervisors: Prof Justin Welbergen, Dr John Martin, Prof Matthias Boer. Topic: Remote sensing of Australian flying-fox camps.
Samantha Yabsley - MRes student (University of Western Sydney; supervisors: Prof Justin Welbergen, Dr Jessica Meade. Topic: Drivers of flying-fox urbanisation

References

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
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, doi: 10.1071/WR21120
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
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: 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, 32: 1151-1162
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, 7: 461-474
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
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), p.10222.
WESTCOTT, D. A., MCKEOWN, A., PARRY, H., PARSONS, J., JURDAK, R., KUSY, B., SOMMER, P., ZHAO, K., DOBBIE, M., HEERSINK, D., CALEY, D. 2015. Implementation of the national flying-fox monitoring program (Rural Industries Research and Development Corporation, Canberra, 2015).
JURDAK, R., SOMMER, P., KUSY, B., KOTTEGE, N., CROSSMAN, C., MCKEOWN, A. AND WESTCOTT, D., 2013, April. Camazotz: multimodal activity-based GPS sampling. In Proceedings of the 12th international conference on Information processing in sensor networks (pp. 67-78). ACM.
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
BIRO, D., FREEMAN, R., MEADE, J., ROBERTS, S., & GUILFORD, T. (2007). Pigeons combine compass and landmark guidance in familiar route navigation. Proceedings of the National Academy of Sciences, 104(18), 7471-7476
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
MEADE, J., BIRO, D., & GUILFORD, T. (2005). Homing pigeons develop local route stereotypy. Proceedings of the Royal Society of London B: Biological Sciences, 272(1558), 17-23

The movement ecology of flying-foxes