Flying foxes are large fruit bats that primarily feed on fruits and flowers. They are highly mobile, traveling long distances in search of seasonal food sources.
Some have been recorded flying more than 20 kilometers from their roost (sleeping area) in a single night to forage, easily crossing islands and even international borders.
Over the course of a year, flying foxes can travel more than 6,000 kilometers, making them among the most far-ranging bats in the world. They often fly too far and too fast for humans to accurately follow their movements.
To better understand how flying foxes move and use different habitats, biologists from the University of the Philippines – Diliman College of Science’s Institute of Biology (UPD-CS IB), along with other researchers, captured nine flying foxes from three species and fitted them with lightweight GPS collars to track their movements.
Rio Renato Constantino, Czarina Espiritu, Maria Sabrina Tabeta, Simeon Gabriel Bejar, and Dr. Mariano Roy Duya of the UPD-CS IB collaborated with Kirk Taray, Jezryl Jaeger Garcia, Dorothy Mariano, Dr. Mary Grace Dacuma, and Dr. Phillip Alviola of UP Los Baños; Sophie Borthwick, Dr. Dolyce Low, and Dr. Ian Mendenhall of Duke-NUS Medical School, Singapore; Dr. Eric Laing of Uniformed Services University, Bethesda, USA; and Dr. Catalino Demetria and Dr. Fedelino Malbas of the Research Institute for Tropical Medicine to describe the movement patterns of the golden-crowned flying fox, Acerodon jubatus; the large flying fox, Pteropus vampyrus; and the small flying fox, P. hypomelanus.
“There’s just not a lot of data about flying fox movements in the Philippines. There have only been two studies about it so far, and both for the same two species (A. jubatus and P. vampyrus) and in the same place (Subic), which forms a fraction of these species’ range. Meanwhile, no such studies have been done for P. hypomelanus at all, anywhere), Constantino shared.
While the flying foxes slept, the researchers quietly approached them with handheld antennas to download the GPS movement data from their collars. Although the limited sample size makes it difficult to generalize the findings to the wider population, the data suggest that A. jubatus and P. vampyrus may travel farther than P. hypomelanus. They differ in how consistently they return to the same roosts, often revisit their feeding sites, and use a wide range of habitats—including built-up areas and farmlands heavily modified by humans.
Constantino found the elusive flying foxes’ movement patterns a fascinating area of study. “By learning where they go, we learn more about their habitat use, what kinds of places they like to frequent. Do they stay in forests? Do they visit cities often?” he said. “At sunset they fly out of the roost and disappear into the night. Where do they go? That’s what we wanted to answer.”
Understanding how flying foxes move across different environments can help inform their conservation and management. “They serve a number of important ecological functions, among them seed dispersal. After a flying fox eats fruit, it poops out the seed, often a considerable distance away from the tree where it obtained its meal. In this way, flying foxes help maintain fruiting tree populations and help forest regeneration,” Constantino explained.
It is important to protect known flying fox roosts and minimize disturbance whenever possible. “If you don’t disturb them, they won’t go away; and if you know where they are, you can avoid them,” Constantino said. The study can help inform land-use planning and conservation strategies that protect both biodiversity and public health.
The study, “Movement patterns of three species of flying foxes across human-modified landscapes in the Philippines,” was published in Mammalia, an international, multidisciplinary, bimonthly journal devoted to the inventory, analysis, and interpretation of mammalian diversity. —Eunice Jean C. Patron
References:
Constantino, R. R. P., Espiritu, C. C., Tabeta, M. S. G., Taray, K. J., Garcia, J. J. L., Bejar, S. G. F., Manzano, D. J. O., Borthwick, S. A., Low, D. H. W., Mendenhall, I. H., Laing, E. D., Demetria, C., Malbas, F., Dacuma, M. G. B., Alviola, P. A., & Duya, M. R. M. (2026). Movement patterns of three species of flying foxes across human-modified landscapes in the Philippines. Mammalia. Advance online publication. https://doi.org/10.1515/mammalia-2025-0097
