Benelli Giovanni, Desneux Nicolas, Romano Donato, Conte Giuseppe, Messing Russell H, Canale Angelo
Insect Behaviour Group, Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124 Pisa, Italy.
French National Institute for Agricultural Research (INRA), Sophia-Antipolis, France.
Sci Rep. 2015 Mar 20;5:9347. doi: 10.1038/srep09347.
In several animal species, aggressive experience influences the characteristics and outcomes of subsequent conflicts, such that winners are more likely to win again (the winner effect) and losers more likely to lose again (the loser effect). We tested the olive fruit fly, Bactrocera oleae (Diptera: Tephritidae), as a model system to evaluate the role of the winner and loser effects in male-male territorial contests. Further, we conducted experiments to test if winning and losing probabilities are affected only by the outcome of the previous contests, or whether the fighting experience itself is sufficient to induce an effect. Both winners and losers of two consecutive encounters displayed higher intensity of aggression and fought longer in subsequent contests. In both cases, they achieved higher fighting success than naïve males. The enhanced fighting performance of both winners and losers was stimulated by merely experiencing a contest, not necessarily by the relative outcome of previous fights. Overall, this study highlights the fact that previous victories and defeats both enhance aggressive behaviour in olive fruit flies, allowing them to achieve higher fighting success in subsequent contests against inexperienced males.
在几种动物物种中，攻击性经历会影响后续冲突的特征和结果，使得胜者更有可能再次获胜（胜者效应），而败者更有可能再次失败（败者效应）。我们以地中海实蝇（双翅目：实蝇科）作为模型系统，来评估胜者效应和败者效应在雄性间领地竞争中的作用。此外，我们进行了实验，以测试胜负概率是否仅受先前竞争结果的影响，或者战斗经历本身是否足以产生一种效应。连续两次交锋的胜者和败者在后续竞争中都表现出更高的攻击强度，战斗时间也更长。在这两种情况下，它们都比无经验的雄性取得了更高的战斗成功率。胜者和败者战斗表现的增强仅仅是通过经历一场竞争刺激的，不一定是由先前战斗的相对结果导致的。总体而言，这项研究凸显了这样一个事实，即先前的胜利和失败都会增强地中海实蝇的攻击行为，使它们在后续与无经验雄性的竞争中取得更高的战斗成功率。
