A test of the sequential assessment game: the effect of increased cost of sampling

Abstract

The sequential assessment game describes a fight between two conspecifics as a statistical sampling process, allowing for specific predictions about fight duration and number of repetitions of a behavioral element depending on relative fighting ability. Fight duration and number of repetitions of a behavioral element correlate moderately to relative fighting ability. Variation in real contests depends on differences between the contestants in the ability to incur cost and the value of the contested resource. I hypothesized that an additional source of variation is differences between individuals in their perception of how dangerous it is to fight. To investigate this, I used the risk of predation to study the effect on the use of different agonistic behaviors in fights between males of the cichlid fish Nannacara anomala. In the group subjected to predation risk, the time until the most escalated behavior (mouth wrestling) was more variable and increased significantly on average. In addition, the duration of fights was significantly longer. In the predator treatment the use of visual assessment and tail beating varied more than in the control, giving a significant positive relationship between the use of low-intensity behaviors and time to mouth wrestling across the group. These relationships were less pronounced in the control group. The effect of predation risk on optimal information transfer is discussed based on the behavioral mechanism suggested by the sequential assessment game. Key words: cichlids, fighting behavior, Nannacara anomala, predation risk, sequential assessment. [Behav Ecol 10:726‐732 (1999)]