Large and high-altitude foraging ranges suggests importance of Wrinkle-lipped free-tailed bats (Chaerephon plicatus) for consuming dispersing pest insects

Abstract High altitude flying bats may contribute to the reduction of dispersing pest insects, yet we are lacking detailed studies on their vertical foraging behavior. Here, we examined the three-dimensional foraging behavior of 18-g wrinkle-lipped free-tailed bats using miniaturized Global Positioning System loggers during the peak emergence of planthoppers, a major pest for rice. We predicted bats to spend most foraging time at high altitudes, i.e., > 110 m above ground, and to use relatively large foraging ranges. Furthermore, we predicted high altitude flights to occur above forested sites, which are locally limited to mountain ridges, and low altitude flight to occur in urban areas and above cropland. Most of the 11 tracked bats used large foraging ranges, covering between 40 to 1,740 km2 during a single night. During single foraging trips, bats traveled 60 km (median), covering a maximum of 26 km (median) in relation to the cave roost. Bats flew at a median altitude of 146 meters above ground, yet occasionally more than 1,600 m above ground. Furthermore, bats spent about 40% of foraging at low altitudes, preferring urban areas and forested sites, but avoided croplands and water bodies. When flying at high altitudes, bats preferred forested sites. Because of its distinct flight behavior and its preferred prey items, i.e. planthoppers, C. plicatus may be crucial in limiting the dispersal capacity of this major rice pest while it is wind drifting to more northern regions in Asia. Protection of this bat is essential for ensuring rice harvests across whole Asia.