Being honest about one's intentions: an evolutionary stable strategy for animal conflicts.

In several vertebrate species it has been demonstrated that individuals recognize each other, and in many other species (even invertebrates) the conditions for it seem to be fulfilled. Individual recognition might therefore be a wide-spread phenomenon in the animal kingdom. This has consequences for the settlement of conflicts between animals: individuals may use information about the outcome of earlier conflicts even if the individuals do not differ in fighting ability. Conflicts will then be asymmetric, and bluff is very unlikely. Possible consequences of individual recognition for the settlement of conflicts are studied by means of simulation. Four strategies will be considered: (1) “Retaliator” (based on Maynard Smith’s models and used as a control condition, (2) “Threat-right” (threatens towards a submissive and will follow with attack if the submissive does not retreat; retreats from a threatening or attacking dominant), (3) “Attack-right” [as (2), but without threatening], and (4) “Threatdominance” [as (2), but with a low probability of threatening and attacking a dominant]. If the knowledge about strength or dominance of the other individuals is perfect, the “Threat-right” strategy (thus a warning before a real attack) turns out to be most successful under a wide variety of conditions. If that knowledge is not perfect (during the learning phase), other strategies can yield better results. The effects of a number of possibilities to settle dominance will be considered (outcome first escalated conflict, last escalated conflict, etcetera). These possibilities will be related to the strategies of settling conflicts, to the expected number of conflicts within the pair of individuals, and to variations in the strength of an individual.