Threat displays are not handicaps

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

Within a general framework of handicap signalling it was proposed that threat displays are handicaps, they can work only if they put the signaller at a disadvantage, which is only acceptable to honest signallers. The aim of the present article is to investigate this proposal with the help of a simple game-theoretical model. It was found: (1) that the use of cost-free signals is an ESS against the invasion of handicapped signals even if cheating is played as part of a mixed strategy in the population; (2) that the use of handicaps may be an ESS against cost-free signals but only if we assume that the invading cost-free signal is not accepted by weak individuals as a signal of strength; (3) that the establishment of a handicapped signal in the first place is an unresolved problem, because both cost free signals and negative-handicaps are evolutionarily stable against the invasion of handicaps; (4) that in contrast to handicaps the use of negative-handicaps can invade a population using cost-free signals (a negative-handicap is a signal which may serve other functions as well); (5) that negative-handicaps are ESS against cost-free signals as well as against handicaps; and (6) thus, the most likely evolutionary end point is that the biggest negative-handicap would be used as a threat display. This is a posture, which prepares the animal most efficiently to fight; hence, most probably it is the initial position of the fighting technique of the given species. (7) Finally, the investigation of the threat displays of well-studied taxa (great tit, cats, dogs, and hoofed mammals) confirms that threat displays are indeed negative-handicaps. They do not put the user into a disadvantaged position, instead the initial position of the species specific fighting technique is used as a threat display as predicted by the present model.

Original languageEnglish
Pages (from-to)327-348
Number of pages22
JournalJournal of Theoretical Biology
Volume221
Issue number3
DOIs
Publication statusPublished - Apr 7 2003

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Display
Display devices
Costs and Cost Analysis
posture
Costs
mammals
cats
Disabled Persons
dogs
methodology
Invasion
animals
Mammals
Vulnerable Populations
Posture
Population
Animals
Cats
Theoretical Models
Simple Game

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)

Cite this

Threat displays are not handicaps. / Számadó, S.

In: Journal of Theoretical Biology, Vol. 221, No. 3, 07.04.2003, p. 327-348.

Research output: Contribution to journalArticle

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