TY - JOUR
T1 - Bats aggregate to improve prey search but might be impaired when their density becomes too high
AU - Cvikel, Noam
AU - Egert Berg, Katya
AU - Levin, Eran
AU - Hurme, Edward
AU - Borissov, Ivailo
AU - Boonman, Arjan
AU - Amichai, Eran
AU - Yovel, Yossi
N1 - Publisher Copyright:
© 2015 Elsevier Ltd. All rights reserved.
PY - 2015/1/19
Y1 - 2015/1/19
N2 - Social foraging is a very common yet extremely complex behavior [1]. Numerous studies attempted to model it [2-7] with little supporting evidence. Studying it in the wild is difficult because it requires monitoring the animal's movement, its foraging success, and its interactions with conspecifics. We present a novel system that enables full night ultrasonic recording of freely foraging bats, in addition to GPS tracking. As they rely on echolocation, audio recordings of bats allow tapping into their sensory acquisition of the world [8]. Rapid changes in echolocation allowed us to reveal the bats' dynamic reactions in response to prey or conspecifics - two key behaviors that are extremely difficult to assess in most animals. We found that bats actively aggregate and forage as a group. However, we also found that when the group became too dense, bats were forced to devote sensory attention to conspecifics that frequently entered their biosonar "field of view," impairing the bats' prey detection performance. Why then did bats fly in such high densities? By emitting echolocation calls, bats constantly provide public information about their detection of prey. Bats could therefore benefit from intentionally flying at a distance that enables eavesdropping on conspecifics. Group foraging, therefore, probably allowed bats to effectively operate as an array of sensors, increasing their searching efficiency [4, 6]. We suggest that two opposing forces are at play in determining the efficient foraging density: on the one hand, higher densities improve prey detection, but on the other hand, they increase conspecific interference.
AB - Social foraging is a very common yet extremely complex behavior [1]. Numerous studies attempted to model it [2-7] with little supporting evidence. Studying it in the wild is difficult because it requires monitoring the animal's movement, its foraging success, and its interactions with conspecifics. We present a novel system that enables full night ultrasonic recording of freely foraging bats, in addition to GPS tracking. As they rely on echolocation, audio recordings of bats allow tapping into their sensory acquisition of the world [8]. Rapid changes in echolocation allowed us to reveal the bats' dynamic reactions in response to prey or conspecifics - two key behaviors that are extremely difficult to assess in most animals. We found that bats actively aggregate and forage as a group. However, we also found that when the group became too dense, bats were forced to devote sensory attention to conspecifics that frequently entered their biosonar "field of view," impairing the bats' prey detection performance. Why then did bats fly in such high densities? By emitting echolocation calls, bats constantly provide public information about their detection of prey. Bats could therefore benefit from intentionally flying at a distance that enables eavesdropping on conspecifics. Group foraging, therefore, probably allowed bats to effectively operate as an array of sensors, increasing their searching efficiency [4, 6]. We suggest that two opposing forces are at play in determining the efficient foraging density: on the one hand, higher densities improve prey detection, but on the other hand, they increase conspecific interference.
UR - http://www.scopus.com/inward/record.url?scp=84921433872&partnerID=8YFLogxK
U2 - 10.1016/j.cub.2014.11.010
DO - 10.1016/j.cub.2014.11.010
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AN - SCOPUS:84921433872
SN - 0960-9822
VL - 25
SP - 206
EP - 211
JO - Current Biology
JF - Current Biology
IS - 2
ER -