Investigation of Large-Scale Navigation Behavior of Echolocating Bats During Natural Foraging, Using GPS and Acoustic-GPS Data-Loggers

Large-scale flight paths of echolocating Japanese greater horseshoe bats were measured using GPS and acoustic GPS (A-GPS) data-loggers. The bats flew up to 23.6 km away from their roost at a maximum. The measured flight paths were broadly divided into two patterns; “staying” and “moving”. Almost bats spent over 70% of time staying while changing sites, indicating that the bats repeated to stay and to fly, and spent much time staying. Analysis for the environmental preference revealed that the bats selectively move and stay in the forest and tend to move along the artificial road. These findings by the high-resolution GPS bio-logging suggest that the bats repeat to stop the various area for foraging, by following the artificial forest roads. Furthermore, the collected A-GPS logger showed that more pulse emissions were observed during staying than moving, strongly supporting that the bats search prey insects using sonar while perching on the tree at the stay-site. Further investigation by A-GPS bio-logging would provide valuable information on bat's echolocation and flight strategies during natural foraging in the large-scale space.