Delbarco-Trillo Javier, McPhee M Elsbeth, Johnston Robert E
Department of Psychology, Cornell University, Ithaca, NY, 14853, USA.
Anim Behav. 2009 Feb;77(2):389-393. doi: 10.1016/j.anbehav.2008.10.012.
In laboratory studies, hamsters (Mesocricetus spp.) exhibit intense male-male aggression, thus making them an excellent model system for studies of the functional and mechanistic bases of aggression. In a field study of golden hamsters (M. auratus) in the wild, however, the few documented male-male interactions were not highly aggressive. Thus, we tested the hypothesis that familiarity modulates aggression in hamsters. Previous investigations of the effects of familiarity on aggression have mostly involved familiarization of unfamiliar individuals through agonistic interactions. Here we allowed male Turkish hamsters (M. brandti) to become familiar with each other by housing them together but separated by a wire-mesh partition (thus 'non-agonistic' familiarity). We found that although non-agonistic familiarity did not decrease investigation of the familiar male, it did decrease the occurrence of fights, the number of fights, and the percentage of time fighting; it also increased the latency to fight. These results are consistent with the 'dear enemy' hypothesis, which proposes that males are less aggressive toward familiar neighbors than to unfamiliar conspecifics because previous interactions have provided enough information about the other individual to render severe aggression unnecessary. Most importantly, our results suggest that information gained about other individuals through non-agonistic interactions decrease the frequency and intensity of fights with those individuals. We conclude that results from laboratory studies on aggression that do not consider the kind of social interactions that individuals have in nature should be interpreted with caution.
在实验室研究中，仓鼠（中仓鼠属）表现出强烈的雄性间攻击行为，因此使其成为研究攻击行为的功能和机制基础的优秀模型系统。然而，在一项对野生金黄仓鼠（金色中仓鼠）的野外研究中，少数有记录的雄性间互动并非高度攻击性的。因此，我们测试了熟悉程度调节仓鼠攻击行为的假设。先前关于熟悉程度对攻击行为影响的研究大多涉及通过争斗性互动使不熟悉的个体熟悉起来。在这里，我们将雄性土耳其仓鼠（布氏中仓鼠）放在一起饲养，但用铁丝网隔开（从而形成“非争斗性”熟悉），让它们彼此熟悉。我们发现，虽然非争斗性熟悉并没有减少对熟悉雄性的探究，但确实减少了打斗的发生、打斗的次数以及打斗时间的百分比；它还增加了打斗的潜伏期。这些结果与“亲爱的敌人”假设一致，该假设提出，雄性对熟悉的邻居比对不熟悉的同种个体攻击性更小，因为先前的互动已经提供了关于另一个体的足够信息，使得严重攻击行为变得不必要。最重要的是，我们的结果表明，通过非争斗性互动获得的关于其他个体的信息会降低与这些个体打斗的频率和强度。我们得出结论，对于不考虑个体在自然环境中所具有的社会互动类型的攻击行为实验室研究结果，应谨慎解读。
