This work was done through Harvey Mudd College, in conjunction with the Concord Field Station at Harvard University. Our work investigated the underlying dynamics that allow a pigeon to make a level 90º turn while flying. The goal of the project was to determine if this motion is the result of a pigeon performing some inertial reconfiguration (eg, twisting their body to change directions), or if there was also an aerodynamic component. By comparing a detailed mathematical model of the kinematics with motion capture date, we were able to determine that pigeons can achieve these low-speed turns similar to helicopters. To turn, pigeons rotate their entire body, altering the direction of aerodynamic forces and direction of the trajectory.
The image below is from our 2011 publication in the Proceedings of the National Academy of Sciences. Click to read the full article.