Ctrax

is an open-source, freely available, machine vision program for estimating the positions and orientations of many walking flies, maintaining their individual identities over long periods of time. It was designed to allow high-throughput, quantitative analysis of behavior in freely moving flies. Our primary goal in this project is to provide quantitative behavior analysis tools to the neuroethology community, thus we've endeavored to make the system adaptable to other lab's setups. We have assessed the quality of the tracking results for our setup, and found that it can maintain fly identities indefinitely with minimal supervision, and on average for 1.5 fly-hours automatically.

To minimize the number of identity errors made during tracking, we provide the FixErrors Matlab GUI that identifies suspicious sequences of frames and allows a user to correct any tracking errors. We also distribute the BehavioralMicroarray Matlab Toolbox for defining and detecting a broad palette of individual and social behaviors. This software inputs the trajectories output by Ctrax and computes descriptive statistics of the behavior of each individual fly. We provide software for three proof-of-concept experiments to show the potential of the Ctrax software and our behavior detectors.