Topic: 3D Trajectories and Network Analyses of Group Behavior within a Chimney Swift Roosting Flock
Date：Sep 18, 09:00~11:00
Bio of the Speaker：
Tyson L. Hedrick - Associate Professor/Lab PI in the University of North Carolina Department of Biology
Prof. Hedrick began a Ph.D. in Biology at Harvard University where he worked under Prof. Andrew Biewener at the Concord Field Station. After completing his thesis, Aerodynamics, biomechanics and neuromuscular control of avian flight, he received a Ph.D. in June of 2004. He then worked as a postdoctoral research assistant with Dr. Thomas Daniel at the University of Washington with funding from the National Science Foundation and DARPA. He started his latest job as an Assistant Professor in the University of North Carolina Department of Biology in July, 2007.
His research focuses on how animals produce and control movement. This expands out into a broader interest in the structure and properties of biological networks as well as how they generate robust outputs in the face of uncertain circumstances and components of varying quality. In a more general sense, his lab examines animal flight aerodynamics and flight behavior across the breadth of flying organisms, from tiny parasitic wasps to fruit flies to large birds and bats.
The flight of thousands of birds in a flock is a natural wonder that immediately raises many questions on how the animals avoid one another, coordinate their movements and create the appearance of group decision making from many individual actions. Bird flocks are also a difficult field recording challenge, with flocks often appearing and disappearing unexpectedly and with many small and nearly identical targets moving together. The Hedrick lab group recently took advantage of the repeated appearance of a Chimney Swift landing flock at a single location to improve field recording techniques to the point where the simultaneous trajectories of ~1,800 birds were recorded as they circled and prepared to land in a single large chimney. Analysis of their trajectories reveals a simple underlying ruleset for group formation and alignment that does not vary with flock density or time and the absence of any leader-follower type interactions during the final landing approach.