Collective motion of birds and locusts

1. Collective motion of birds and locusts David J. T. Sumpter Department of Mathematics Uppsala University

9. Are there simple behavioural rules which explain all these very different outcomes?

10. How the two birds x and y change position:

13. β=1 β=0.98

14. Does distance between established routes explain these very different outcomes?

16. a b W 1 G 12 G 5 W 2 G 2 W 5 W 6 G 6 W 3 G 7 W 4 G 9 c C 2 G 3 G 8 C 3 G 11 G 10 C 4 G 1 G 4 C 1 Dominance Hierarchy

17. d c Proportion improvement in paired flight by singly less efficient bird Proportion improvement in paired flight by singly more efficient bird

20. 1D self-propelled particles Position: Velocity: Czirok, Vicsek et al. (1999)

21. 1D self-propelled particles Time Average direction Space Time Position: Velocity:

22. 1D self-propelled particles Time Average direction Space Time Position: Velocity:

23. 1D self-propelled particles Time Average direction Space Time Position: Velocity:

24. 1D self-propelled particles Average Direction Particle Density

28. Model vs data

29. Model vs data

30. Collective vs individual motion Treatment 0 – 60 minutes 60 – 180 minutes Control

31. High density treatment

32. Control experiments

33. Alignment Activity (movinglocusts)

34. Activity vs Alignment

35. Some conclusions • Activity is the key parameter in predicting alignment in locusts. • Degree of conflict is the key parameter in predicting compromise in pigeons. • In both cases there is a sharp transition from one type of behaviour as this parameter is changed.

36. Collective Animal Behaviour www.collective-behavior.com

37. Collective Animal Behaviour www.collective-behavior.com

38. Collective Animal Behaviour www.collective-behavior.com

39. Collective Animal Behaviour www.collective-behavior.com

40. Collective Animal Behaviour www.collective-behavior.com

41. References Biro, D., Sumpter, D. J. T., Meade, J. & Guildford, T. (2006) From compromise to leadership in pigeon homing, Current Biology, 2006 16: 2123-2128. Buhl, J., Sumpter, D. J. T., Couzin, I. D., Hale, J. J., Despland, E., Miller, E. & Simpson, S. J. (2006) From disorder to order in locust marching, Science, 312, 1402 - 1406. . Yates, C., Erban, R., Escudero, C., Couzin, I. D. ,Buhl, J., Kevrekedis, I.,Maini, P. K., Sumpter, D. J. T. (2009)Inherent noise can facilitate coherence in collective swarm motion, Proceedings of the National Academy of Sciences, almost accepted. Hale, J. J. (2008) Automated tracking of locusts and humans, DPhil thesis, University of Oxford. Sumpter, D. J. T., Krause, J. James, R., Couzin, I. D. and Ward A. J. W (2008) Consensus decision-making by fish, Current Biology, 18, 1773–1777. Ward, A. J. W., Sumpter, D. J. T., Couzin, I. D., Hart, P. J. B. and Krause, J. (2008) Quorum decision-making facilitates information transfer in fish shoals Proceedings of the National Academy of Sciences, 105, 6948-6953. Sumpter, D. J. T. (2006) The principles of collective animal behaviour, Philosophical Transactions of the Royal Society of London: Series B, 361, 5-22. Webpage: http://www.math.uu.se/~david/web/