Leadership in fish shoals

  title={Leadership in fish shoals},
  author={Jens Krause and Daniel Hoare and Stefan Krause and Charlotte K. Hemelrijk and Daniel I. Rubenstein},
  journal={Fish and Fisheries},
Leadership is not an inherent quality of animal groups that show directional locomotion. However, there are other factors that may be responsible for the occurrence of leadership in fish shoals, such as individual differences in nutritional state between group members. It appears that front fish have a strong influence on directional shoal movements and that individuals that occupy such positions are often characterised by larger body lengths and lower nutritional state. Potential interactions… 
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Positioning Behaviour in Roach Shoals: The Role of Body Length and Nutritional State
The results suggest that the initiation of new swimming directions in stationary shoals does not follow the same principles as positioning behaviour in shoals that are already on the move, which could provide a functional explanation for the occurrence of food-deprived fish in front positions.
Can a minority of informed leaders determine the foraging movements of a fish shoal?
In a strongly gregarious species, such as the golden shiner, a minority of informed individuals can lead a shoal to food, either through social facilitation of foraging movements or by eliciting following behaviour.
The social organization of free‐ranging fish shoals
No evidence was found that shoals might break up into sub-units of individuals that are more phenotypically assorted than their original shoals, and the mechanisms by which assortative groups may arise and the consequences of low group fidelity for the evolution of cooperative behaviour are discussed.
The social organization of fish shoals: a test of the predictive power of laboratory experiments for the field
Predictions based on experiments in captivity regarding p for conspecifics, individuals of similar body length and unparasitized fish were highly consistent with field observations on free‐ranging shoals whereas p for familiar conspecies and kin remain to be conclusively demonstrated in the field.
Is there always an influence of shoal size on predator hunting success
It was found that the leading fish of a shoal was attacked significantly more often than fish in other shoal positions, indicating that predation risk was not shared equally among shoal members.
  • Jens Krause
  • Environmental Science
    Biological reviews of the Cambridge Philosophical Society
  • 1994
A general overview of position-related fitness differences in group-living animals is given for the first time and it is suggested that edge positions achieve a higher net-energy pay-off and should therefore be preferred by individuals with low energy reserves.
2 Swimming Capacity
Mortality risk of spatial positions in animal groups: The danger of being in the front
We modified Hamilton's (1971) selfish herd model by introducing directional movement to the prey groups and the predators. The consequences of this modification with regards to differential predation
The effect of 'Schreckstoff' on the shoaling behaviour of the minnow: a test of Hamilton's selfish herd theory
  • J. Krause
  • Environmental Science
    Animal Behaviour
  • 1993
It is suggested that peripheral positions in fish shoals suffer higher predation risks and support Hamilton's selfish herd theory.