Meeting Abstract

100.10  Sunday, Jan. 6  Flight modalities in the group behavior of free-tailed bats. HRISTOV, N.I.*; ALLEN, L.C.; CHADWELL, B.; Winston-Salem State Univ., Winston-Salem; WSSU, Winston-Salem; N.E. Ohio Med. Univ., Rootstown nickolay.hristov@centerfordesigninnovation.org

From the seemingly chaotic movement of unicellular organisms to the grandiose migrations of ungulates, the collective behavior of organisms belongs to some of the most striking displays in nature. Based on the characteristics of the individual but meaningful in the context of the group, the behavior of animal groups poses an evolutionary paradox – how to balance the proximal and ultimate costs and benefits of grouping. Bats are excellent models for studying collective behavior displaying a range of collective patterns that can offer insight about why and how organisms group. Studying the group behavior of bats poses significant challenges; nevertheless, recent advances in visualization methods give new opportunities to study the natural group behavior of bats in the field. Using an array of high-speed video cameras we recorded (at their natural roost) the emergence and return of a large colony of Brazilian free-tailed bats (Tadarida brasiliensis). Three-dimensional reconstructions of the flight kinematics and behavior of individual bats in the column, paired with a reconstruction of the group formation indicate significant differences in the flight behavior and grouping pattern of individual under these two different flight regimes. Emerging bats emerge utilize powered flight, fly slower, are spaced closer and interact more with each other. The group displays characteristics of a formation for predator defense (avoidance). Bats returning to the roost predominantly glide/dive, move faster, space themselves further apart, and rarely contact each other. The formation appears organized by the need to avoid collisions. How morphology, ecology, and flight performance of bats affect these two flight regimes remains to be studied.