Daytime behavior of <i>Pteropus vampyrus</i> in a natural habitat: the driver of viral transmission

Abstract

Flying foxes, the genus Pteropus, are considered viral reservoirs. Their colonial nature and long flight capability enhance their ability to spread viruses quickly. To understand how the viral transmission occurs between flying foxes and other animals, we investigated daytime behavior of the large flying fox (Pteropus vampyrus) in the Leuweung Sancang conservation area, Indonesia, by using instantaneous scan sampling and all-occurrence focal sampling. The data were obtained from 0700 to 1700 hr, during May 11–25, 2016. Almost half of the flying foxes (46.9 ± 10.6% of all recorded bats) were awake and showed various levels of activity during daytime. The potential behaviors driving disease transmission, such as self-grooming, mating/courtship and aggression, peaked in the early morning. Males were more active and spent more time on sexual activities than females. There was no significant difference in time spent for negative social behaviors between sexes. Positive social behaviors, especially maternal cares, were performed only by females. Sexual activities and negative/positive social behaviors enable fluid exchange between bats and thus facilitate intraspecies transmission. Conflicts for living space between the flying foxes and the ebony leaf monkey (Trachypithecus auratus) were observed, and this caused daily roosting shifts of flying foxes. The ecological interactions between bats and other wildlife increase the risk of interspecies infection. This study provides the details of the flying fox’s behavior and its interaction with other wildlife in South-East Asia that may help explain how pathogen spillover occurs in the wild.

Diurnal behavior and activity budget of the golden-crowned flying fox (<i>Acerodon jubatus</i>) in the Subic bay forest reserve area, the Philippines

“…In this study, we found that the golden-crowned flying foxes showed hanging alert behavior when they were faced with anthropogenic exposure by tourists and/or predation by aerial predators (bird in the genus Spilornis ), but there was no disturbance by non-human primates. This is in contrast to our previous study on P. vampyrus in Indonesia [ 14 ], wherein the roosting site of the flying foxes was invaded by non-human primates ( Trachypithecus auratus ), an average 3.3 ± 0.5 times a day. Therefore, hanging alert was not included in the statistical analysis for behavioral variation with the time of the day.…”

“…This would explain the positive correlation between the frequency of self-grooming and humidity found in this study. This behavior typically occurred early in the morning, consistent with the study of diurnal variation in self-grooming behavior of P. vampyrus and P. poliocephalus [ 7 , 14 ].…”

“…This could be the reason why bats need to save the energy for foraging at night by sleeping during the day. Compared with a previous study on P. vampyrus living in Leuweung Sancang conservation area, Indonesia [ 14 ], A. jubatus in this study site spent a greater amount of the daytime sleeping. This could be explained by lesser disturbance by other wildlife in this study area, compared with P. vampyrus , which were faced with high disturbance by non-human primates during daytime [ 14 ].…”

“…The most frequently observed activity in the group of flying foxes was sleeping, followed by wing flapping, self-grooming, hanging relaxation, wing spread, movement, mating/courtship, aggression, hanging alert, excretion and scent marks. Connell et al [ 7 ] and Hengjan et al [ 14 ], working on Pteropus poliocephalus and P. vampyrus , respectively, also found that sleeping (resting state) was the most dominant behavior, with the highest frequency in late evening, compared with the other times in a day. A. jubatus also showed this tendency.…”

The spleen morphophysiology of fruit bats

“…Large‐sized fruit bats, such as flying foxes, are nomadic foragers capable of flying up to 100 km from the roosting site in one night (Hengjan et al, ). Fruit bats, being social beings, are reported to engage in conflicts over food with other species such as monkeys (Hengjan et al, ). Fruit‐eating behaviour is also an important factor aiding in spreading of viruses between species.…”