Abstract

Territorial animals are expected to adjust their response to intruders according to the perceived threat level. One of the factors that drives threat level is the identity of the intruder. The dear enemy phenomenon theory postulates that individuals should respond with lower intensity to neighbors, already possessing a territory, than to strangers that may fight to evict them. In social species, the hierarchical status of the intruder might also mediate this response. Such behavioral adjustments presuppose a capacity to discriminate between individuals posing different threat levels. Here, we tested the behavioral response of Alpine marmots to territorial intrusions in a wild population. We compared both dominant females’ and males’ responses to scents from neighbor and stranger dominant males (dear enemy phenomenon) and to dominant and subordinate stranger males (social status-specific response). In addition, we tested for any covariance between male scents and social status. We showed that female and male dominant marmots do not adjust the intensity of their behavioral responses to whether the intruder’s territory is bordering or not (neighbors or strangers) or to the intruder’s social status, even though dominant and subordinate males are thought to pose different threats and social status is encoded in scents. Thus, we did not find support for the dear enemy phenomenon and conclude instead that, in dominant Alpine marmots, no intruder should enter a foreign territory. Research taking a more holistic approach of the evolution and maintenance of territoriality is required to understand the flexibility of responses to intruders in group-living species.

中文翻译：

---

邻里霸凌：领土对土拨鼠的邻居或陌生人的反应没有差异

摘要

预计领地动物会根据感知到的威胁级别来调整对入侵者的反应。造成威胁级别的因素之一是入侵者的身份。亲爱的敌人现象理论假定，与对可能要驱逐他们的陌生人的反应相比，个人对已经拥有领土的邻居的反应强度应较低。在社会物种中，入侵者的等级状态也可能介导此响应。这种行为调整的前提是要能够区分构成不同威胁级别的个人。在这里，我们测试了土拨鼠对野生种群对领土入侵的行为反应。我们比较了男性和女性对邻居和陌生男性的气味的反应（亲爱的敌人现象）以及对男性和从属陌生男性的气味的反应（针对特定社会地位的反应）。此外，我们测试了男性气味与社会地位之间的协方差。我们表明，雄性和雄性土拨鼠不会根据入侵者的领土是否毗邻（邻居或陌生人）或入侵者的社会地位来调整其行为反应的强度，即使据认为雄性和下属雄性构成不同的威胁而社会地位则用气味来表达。因此，我们没有找到对亲爱的敌人现象的支持，而是得出结论，在占主导地位的高山土拨鼠中，任何入侵者都不应进入外国领土。