Behavioural ecology and swarm intelligence
Shoals of fish often achieve things that individual specimens are unable to do. It is easier for fish to find food, to recognise enemies quickly, and to reproduce more successfully in a shoal. In the case of humans, too, decisions taken collectively often turn out to be better than those made by individuals. For this reason, social networks and collective decision processes are not only interesting for ecology, but also for decision management in politics, medicine or the economy. In these systems, principles such as competition, organisation, cooperation and resource management play an important role. For this reason, at IGB we explore how decision processes can be improved. For example, we use knowledge of the swarm behaviour of fish to derive models for the dynamics and organisation of groups of people.
The authors outline key mechanisms by which fishing can change the shoaling tendency and collective behaviour of exploited species – an issue that is rarely considered and poorly understood. They highlight potential consequences for fish populations and food webs, and discuss possible repercussions for fisheries and conservation strategies.
The authors show that three-spined stickleback infected with tapeworm Schistocephalus solidus can disrupt the transmission of flight responses within a shoal, thereby not only increasing their own predation risk but also that of their uninfected shoal members. The study uncovers a potentially far-reaching fitness consequence of grouping with infected individuals.