Johnsson JI, Åkerman A
Section of Animal Ecology, Department of Zoology, University of Göteborg
Anim Behav. 1998 Sep;56(3):771-776. doi: 10.1006/anbe.1998.0824.
The costs associated with initial conflicts could be reduced if animals can assess the fighting ability of possible future opponents by watching their contest success against other individuals. We tested this hypothesis by conducting repeated dyadic dominance trials on size-matched juvenile rainbow trout, Oncorhynchus mykiss. In the first trial a dyadic contest was 'observed' by a single fish separated by a transparent divider. In the second trial, the observer was paired against either the 'familiar' dominant fish or an unfamiliar dominant fish from the first trial. We predicted that observers should settle conflicts with previewed opponents faster and with less aggression than those with unfamiliar fish. This prediction was supported for observers that lost against a previewed competitor, since these fish reduced their aggression more rapidly than did unfamiliar observers. Familiar observers that won, however, showed a more rapid increase in aggression compared with unfamiliar winning observers. This suggests that, regardless of whether an observer challenges the initial dominant, this 'decision' is taken more rapidly in conflicts with preassessed contestants, because of the a priori information about their fighting ability. Since preassessment could save energy and allow effort to be concentrated on contests with a high payoff/probability of winning, selection may favour preview strategies when contest competition over resources is important for fitness. Copyright 1998 The Association for the Study of Animal Behaviour.
如果动物能够通过观察未来潜在对手与其他个体的争斗胜负情况来评估其战斗能力，那么与初次冲突相关的成本就可能降低。我们通过对体型匹配的幼年虹鳟（Oncorhynchus mykiss）进行重复的二元优势试验来检验这一假设。在第一次试验中，一条鱼被透明隔板隔开“观察”一场二元争斗。在第二次试验中，观察者与第一次试验中“熟悉”的优势鱼或不熟悉的优势鱼配对。我们预测，与不熟悉的鱼相比，观察者与预先观察过的对手解决冲突的速度更快，攻击性更低。对于输给预先观察过的竞争对手的观察者，这一预测得到了支持，因为这些鱼比不熟悉的观察者更快地降低了攻击性。然而，获胜的熟悉观察者与获胜的不熟悉观察者相比，攻击性增加得更快。这表明，无论观察者是否挑战最初的优势者，由于事先了解对手的战斗能力，在与预先评估过的对手冲突时，做出这个“决定”的速度会更快。由于预先评估可以节省能量，并使精力集中在具有高回报/高获胜概率的争斗上，当争夺资源的竞争对适应性很重要时，选择可能有利于预先观察策略。版权所有1998动物行为研究协会。
