Probing motivational state during agonistic encounters in animals
Probing motivational state during agonistic encounters in animals
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DOI：
10.1038/29980
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发表时间：
1998-05-07
期刊：
影响因子：
64.8
通讯作者：
Dick, JTA
中科院分区：
文献类型：
--
作者：
Elwood, RW;Wood, KE;Dick, JTA
动物通常通过直接攻击来争夺资源：例如，蜘蛛为网站而战（1），雄性红鹿为雌性而战（2），蝎蝇为猎物而战（3）。博弈论的应用大大提高了我们对这种竞赛演变的理解（4-7）。一个普遍的结论是，如果可能的话，动物应该在比赛中做出战术决定之前评估相对的战斗能力和资源的价值。这些战术决策被认为是由不同的动机状态（7，9）介导的，但这一基本假设尚未得到验证。在这里，我们通过探索寄居蟹在争夺腹足类贝壳所有权时的动机状态来测试积累的理论。该测试使用了一种对螃蟹来说新奇的刺激，它会产生惊吓反应，这种反应的持续时间是衡量战斗动机的独立指标。我们表明，动机状态不同，在比赛的早期阶段，根据潜在的收益资源价值。对手的相对大小对动机状态没有影响。在这些竞赛中，相对规模既不能预测竞赛的可能成本，也不能预测获胜的概率。
Animals commonly compete for resources by direct aggression: for example, spiders fight for web sites(1), male red deer fight for females(2), and scorpionflies fight for prey(3). The application of game theory has considerably advanced our understanding of the evolution of such contests(4-7). A general conclusion is that, if possible, animals should assess both the relative fighting abilities and the value of resources before making tactical decisions during contests(8). These tactical decisions are assumed to be mediated by differing motivational state(7,9), but this fundamental assumption has yet to be tested. Here we test the accumulated theory by probing the motivational state of hermit crabs during fights over the ownership of gastropod shells. The test uses a stimulus, novel to the crabs, that produces a startle response, the duration of which is an independent measure of the motivation to fight. We demonstrate that motivational state differs at an early stage of the contest according to the potential gain in resource value. There was no effect of relative size of the opponent on motivational state. In these contests, relative size neither predicted the likely cost of the contest nor the probability of victory.