Groups confuse predators by exploiting perceptual bottlenecks: a connectionist model of the confusion effect

@article{Krakauer2004GroupsCP,
  title={Groups confuse predators by exploiting perceptual bottlenecks: a connectionist model of the confusion effect},
  author={David C. Krakauer},
  journal={Behavioral Ecology and Sociobiology},
  year={2004},
  volume={36},
  pages={421-429}
}
  • D. Krakauer
  • Published 1 June 1995
  • Biology
  • Behavioral Ecology and Sociobiology
Aggregation is a well documented behaviour in a number of animal groups. The “confusion effect” is one mechanism thought to mitigate the success of predators feeding on gregarious prey and hence favour aggregation. An artificial neural network model of prey targeting is developed to explore the advantages prey species might derive through a tendency to group. The network illustrates how an abstract model of the computational mechanisms mediating the perception of prey position is able to show a… 
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References

SHOWING 1-10 OF 38 REFERENCES
Geometry for the selfish herd.
  • W. Hamilton
  • Environmental Science
    Journal of theoretical biology
  • 1971
Evidence for the dilution effect in the selfish herd from fish predation on a marine insect
TLDR
Field observations of predation on a marine insect are presented, in which it is possible, for the first time, to quantify the magnitude of the dilution effect and distinguish it from other benefits of group living.
Oddity and the ‘confusion effect’ in predation
SCHOOLING BEHAVIOR IN THE GUPPY (POECILIA RETICULATA): AN EVOLUTIONARY RESPONSE TO PREDATION
  • B. Seghers
  • Environmental Science
    Evolution; international journal of organic evolution
  • 1974
TLDR
This report presents a new source of evidence favoring an antipredator role for schooling in guppies from natural populations of a small tropical freshwater fish, the guppy, in the Northern Range Mountains of Trinidad, West Indies.
The Principle of Optimal Behavior and the Theory of Communities
The notion that behavior maximizes fitness can be used as a tool for generating testable hypotheses concerning the expected behavior of animals. In turn, the expected behavior of animals with respect
Provenance, shoal size and the sociobiology of predator-evasion behaviour in minnow shoals
  • A. Magurran, T. Pitcher
  • Environmental Science
    Proceedings of the Royal Society of London. Series B. Biological Sciences
  • 1987
TLDR
Mnows from provenances with and without pike exhibited a similar repertoire of antipredator behaviour patterns, but those sympatric with the predator integrated their tactics more effectively and regained pre-exposure behaviour sooner after each encounter.
Arms races between and within species
  • R. Dawkins, J. Krebs
  • Biology
    Proceedings of the Royal Society of London. Series B. Biological Sciences
  • 1979
TLDR
The arms race concept is suggested to help to resolve three long-standing questions in evolutionary theory: one lineage may drive the other to extinction, one may reach an optimum, thereby preventing the other from doing so, and both sides may reach a mutual local optimum.
The Serengeti Lion: A Study of Predator-Prey Relations
TLDR
Based on years of field observation, this is the most comprehensive scientific study yet published on the behavior of free-living lions.
Functions of Shoaling Behaviour in Teleosts
Predators and food are the keys to understanding fish shoals; synchronised co-operation defeats predators, and optimal food gathering in shoals reflects a shifting balance between joining, competing
...
...