title: Rapid shifts of sonar attention by Pipistrellus abramus during natural hunting for multiple prey.
abstract: Flight paths of echolocating Japanese house bats, Pipistrellus abramus, were tracked during insect hunting in a natural setting using a 32-microphone array. The array surrounded the foraging area, locating each bat, and determined the directional aim of the sonar beam. Successive interceptions, indicated by feeding "buzzes" and post-buzz pauses, occurred singly at intervals from over 20 s down to multiple interceptions at 2-3 s intervals. Bats flew on looping, curved paths. Turning radius tightened as rate of interceptions increased, keeping the bat in a smaller area of higher capture density. Broadcast beams shifted direction during search, often alternating between the direction of flight and another direction where, moments later, the next interception would occur. Broadcasts also shifted direction between the current target and the next target. Bats time-share biosonar attention between objects by alternating acoustic gaze. During search, most interpulse intervals (IPIs) were 70-120 ms, but bats interspersed long IPIs up to 200 ms when the rate of interception was low and flight paths followed broad curves. Mathematical modeling of search paths demonstrated that circular flight-paths with occasional long IPIs would be more effective for target search than either random, correlated random, or linear flights.
authors.affiliation: Faculty of Life and Medical Sciences, Doshisha University, 1-3 Tatara-Miyakotani Kyotanabe, Kyoto 610-0321, Japan.
authors.forename: Emyo
authors.initials: E
authors.lastname: Fujioka
authors.affiliation: Brain Science Institute, RIKEN, 2-1 Hirosawa Wako, Saitama 351-0198, Japan.
authors.forename: Ikkyu
authors.initials: I
authors.lastname: Aihara
authors.affiliation: Faculty of Life and Medical Sciences, Doshisha University, 1-3 Tatara-Miyakotani Kyotanabe, Kyoto 610-0321, Japan.
authors.forename: Shotaro
authors.initials: S
authors.lastname: Watanabe
authors.affiliation: Faculty of Life and Medical Sciences, Doshisha University, 1-3 Tatara-Miyakotani Kyotanabe, Kyoto 610-0321, Japan.
authors.forename: Miwa
authors.initials: M
authors.lastname: Sumiya
authors.affiliation: Faculty of Life and Medical Sciences, Bio-Navigation Research Center, Doshisha University, 1-3 Tatara-Miyakotani Kyotanabe, Kyoto 610-0321, Japan.
authors.forename: Shizuko
authors.initials: S
authors.lastname: Hiryu
authors.affiliation: Department of Neuroscience, Brown University, 185 Meeting Street, Box G-LN, Providence, Rhode Island 02912.
authors.forename: James A
authors.initials: JA
authors.lastname: Simmons
authors.affiliation: Faculty of Life and Medical Sciences, Bio-Navigation Research Center, Doshisha University, 1-3 Tatara-Miyakotani Kyotanabe, Kyoto 610-0321, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Riquimaroux
authors.affiliation: Faculty of Life and Medical Sciences, Bio-Navigation Research Center, Doshisha University, 1-3 Tatara-Miyakotani Kyotanabe, Kyoto 610-0321, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D001288:Attention; D001307:Auditory Perception; D002685:Chiroptera; D004455:Echolocation; D005426:Flight, Animal; D007564:Japan; D008962:Models, Theoretical; D009949:Orientation; D011235:Predatory Behavior