Abstract

The function of holding territories is primarily to have access to resources like food and mates. However, it is costly in terms of energy and time investment. Solitary-living, territorial species are known to reduce these costs by being more aggressive towards unfamiliar strangers and less aggressive towards neighbors. However, in social, territorial species, neighbors can impose a greater threat than strangers. We tested whether the highly social Asiatic wild dogs/dholes (Cuon alpinus) exhibit the “nasty neighbor” or the “dear enemy” phenomena in Tadoba Andhari Tiger Reserve (TATR), Maharashtra, India. We conducted scat translocation experiments where we presented fresh scats collected from unique donor groups to a resident dhole group and tested the type and the intensity of behavioral response (duration) to the stimulus. Dholes responded differentially to the two treatments suggesting they exhibit neighbor-stranger discrimination. Overall, strangers elicited a stronger response with longer duration and larger packs were less likely to respond to the stimulus than smaller packs. Differences found between categories of dhole scent marks establish the importance of olfactory communication, especially “counter-marking” in the species. Within recipient packs, individual status affected the response to trials wherein the alpha pair reacted more intensively to strangers than others. Our study provides experimental evidence to demonstrate that dholes exhibit the “dear enemy” phenomenon.

Significance statement

Animals defend territories from other members of their own species, but intrusions are commonplace in the wild. Different intruders may pose different levels of threats, and hence, intruders are treated differentially to minimize the energetic costs of territorial defense. In some animals, neighbors with well-established territories may become less aggressive towards each other. This is known as the dear enemy effect. By contrast, at times neighbors may represent a greater threat than strangers which is known as the “nasty neighbor” effect. We experimentally show that dholes exhibit the dear enemy phenomenon by responding more intensively to strangers than familiar neighbors. We show how response varied based on hierarchy in a pack as well as the pack sizes. Furthermore, we found that, both in core as well as buffer areas of their own territory, this relationship was consistent.

中文翻译：

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陌生人危险：社会食肉动物亚洲野狗（Cuon alpinus）对陌生人和邻居的不同反应

摘要

持有领土的功能主要是获得食物和配偶等资源。然而，就能量和时间投资而言，它是昂贵的。众所周知，独居、有领土的物种通过对不熟悉的陌生人更具攻击性和对邻居的攻击性降低来降低这些成本。然而，在社会性、地域性的物种中，邻居可以施加比陌生人更大的威胁。我们测试了高度社交的亚洲野狗/野狗（Cuon alpinus) 在印度马哈拉施特拉邦的 Tadoba Andhari Tiger Reserve (TATR) 展示“讨厌的邻居”或“亲爱的敌人”现象。我们进行了粪便易位实验，我们将从独特的供体组收集的新鲜粪便呈现给常驻 dhole 组，并测试对刺激的行为反应（持续时间）的类型和强度。Dholes 对这两种治疗方法的反应不同，这表明它们表现出对邻居陌生人的歧视。总体而言，陌生人在持续时间较长的情况下引发了更强的反应，而较大的包装比较小的包装更不可能对刺激做出反应。dhole 气味标记类别之间发现的差异确定了嗅觉交流的重要性，尤其是在物种中的“反标记”。在收件人包内，个体状态影响了对试验的反应，其中阿尔法对对陌生人的反应比其他人更强烈。我们的研究提供了实验证据来证明 dholes 表现出“亲爱的敌人”现象。

意义陈述

动物保护自己物种的其他成员的领土，但入侵在野外是司空见惯的。不同的入侵者可能会造成不同程度的威胁，因此，入侵者会受到不同的对待，以最大限度地降低领土防御的能量成本。在某些动物中，拥有完善领土的邻居可能会变得不那么咄咄逼人。这被称为亲爱的敌人效应。相比之下，有时邻居可能比陌生人造成更大的威胁，这被称为“讨厌的邻居”效应。我们通过实验表明，dholes 通过对陌生人的反应比对熟悉的邻居更强烈的反应来表现出亲爱的敌人现象。我们展示了响应如何根据包中的层次结构和包大小而变化。此外，我们发现，无论是在自己领土的核心区域还是缓冲区，