Collective Behaviour of Insect Swarms under External Perturbations

• Applicant: Dr. Michael Sinhuber
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics
• Term: from 2018 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 396632606

In nature, a wide array of animal species tends to form aggregates that often show complex and dynamic spatio-temporal patterns. The underlying interactions of the individuals and the resulting, potentially collective, swarming behaviour is subject of current research. Even though natural swarms are subject to environmental flows and disturbances, the interactions between these flows, be it wind gust, convective flows or water currents, and collective swarming are completely unknown. Investigating this coupling is the center of the proposed research project. To do this, the interaction between a non-biting midge species, Chironomus riparius, and a well-controlled convective Rayleigh-Bénard flow are to be investigated in a laboratory experiment. In nature, midge swarms tend to form at dusk and dawn over geometric features. In the laboratory, this swarming can be triggered using external timed lights, making Chironomus riparius an optimal model system to investigate collectively swarming animals. Using a heated plate, a convective flow is produced and the interactions with the midges swarms are investigate using hardware-synchronized cameras. Using stereomatching techniques and Lagrangian particles tracking algorithms know from turbulence research, full three-dimensional trajectories of all midges along with their velocities and acceleration can be computed, yielding full statistical information about the swarm. By varying the temperature of the driving heat plate and, thus, the strength of the convective flow, dynamic effects of environmental flows on collectively swarming midges can be quantitatively investigated. Using novel topological methods, such as dynamic persistent homology, global, structural interactions between the environment and animal swarms can be investigated in detail. Knowledge of these interactions is essential to obtain a deeper physical understanding about the nature of collective behaviour and potentially useful in engineering applications to design effective distributed systems that can solve complex tasks collectively.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professor Dr. Nicholas T. Ouellette