Meeting Abstract

23.4  Wednesday, Jan. 4  Methods for describing and analyzing group behavior in bats: A case study in the Brazilian free-tailed bat CHADWELL, B.A.*; HRISTOV, N.I.; ALLEN, L.C.; Guilford College, Greensboro; Center for Design Innovation/Winston-Salem State Univ.; Salem College, Winston-Salem chadwellba@guilford.edu

The collective behavior of large groups of organisms has long attracted the interest of diverse disciplines of science. However, technical and computational limitations have minimized empirical work and previous studies have focused on computational modeling and simulation approaches. Advances in high-speed videography and thermal infrared imaging, spatial calibration and computational analysis have allowed the accurate recording and reconstruction of three-dimensional position of individuals in large groups. How does one make sense of these rich data? In particular, what is the appropriate method for calculating the position and movement of individuals relative to one another? Using the Brazilian free-tailed bat (Tadarida brasiliensis) as a model, the three-dimensional trajectories of free-tail bats during their emergence were reconstructed from videos captured by an array of time-synchronized, space-calibrated, high-speed thermal cameras. We propose alternate methods for describing the shape and dynamics of the flight formation as well as for calculating and analyzing the distances and relative orientation between specific bat-pairs. Furthermore, we present the effect of each approach on the overall analysis and interpretation. Empirical data and their analysis are important for validating previous computational work and for understanding the behavior and mechanism of grouping in large colonies of bats and collective movement in general.