Chris Braam - Predator induced waves in self-organized flocks of starlings

In 2010 Hildenbrandt et al presented StarDisplay, a model of self-organized flocks of starlings. The flocks that emerged in the model showed a close resemblance to real flocks of starlings flying above their sleeping area. A key difference between the modeled flocks and real flocks is that the volume of modeled flocks is consistently lower. In this project it is argued that this difference in volume is likely to be caused by a difference in reaction times between the real flocks and the modeled flocks. Empirical data suggests that the reaction times used in the model are likely to be an underestimate of the actual reaction times of starlings. An experiment was designed in which the effect of reaction time on flock structure is tested in the model. A very important environmental influence on flocking patterns that was so far left out of the model is predatory threat. In this project a predator is introduced to the model that performs repeated dive attacks on the flock of starlings. The behavior of the modeled starlings is extended to incorporate predator avoidance behavior. Flocking patterns such as herding, hour glass, vacuole and waves of agitation, well known from empirical studies, are observed in the model as a result of predator prey interactions. Waves of agitation are analyzed in more detail. An experiment was designed in which the effect of reaction time and, indirectly, flock structure on the speed and duration of the waves was tested.