Male–male competition shapes resource distributions and reproductive success among individuals, and can drive trait evolution when phenotypes differ in competitive abilities and/or strategies. Divergence of populations, regardless of the cause, is often accompanied by divergence in male competitive ability, and such asymmetries can play an important role in mediating the interactions and evolutionary trajectory of the nascent lineages. Here, we designed a field experiment to examine the importance of color, a divergent trait, in determining territorial contest outcomes in the poison frog Oophaga pumilio. Males of different O. pumilio color morphs differ in aggression level, suggesting a potential dominance hierarchy between these divergent phenotypes. In a contact zone between red and blue‐color morphs, we first removed territorial males from their calling sites, and examined whether certain color morph(s) were better at establishing in these now‐vacant territories. We then staged a territorial contest by simultaneously releasing the original and the new occupant to their point of capture. Surprisingly, we found no significant effect of color on acquiring territories or winning staged contests. However, the original occupants won against the new occupant in 84% of the staged contests, revealing a strong prior residence effect. This suggests that asymmetries that stem from prior residency override coloration in predicting contest outcomes of male–male territorial contests in wild O. pumilio. Thus, contradicting our hypothesis, male–male territorial competition alone seems unlikely to exert selection on coloration in this contact zone.

中文翻译：

---

先前的居留效应决定了彩色多态毒蛙在男女领土竞争中的成功

男性与男性之间的竞争会影响个体之间的资源分配和生殖成功，当表型在竞争能力和/或策略上存在差异时，就会推动性状的演变。不论原因为何，人口的分化通常伴随着男性竞争能力的分化，而这种不对称性在介导新生世系的相互作用和进化轨迹中起着重要的作用。在这里，我们设计了一个野外实验，以检验颜色（发散特征）在确定毒蛙Oophaga pumilio的领土比赛结果中的重要性。不同的O. pumilio的雄性颜色形态在攻击水平上有所不同，表明这些不同表型之间存在潜在的优势层次。在红色和蓝色变色之间的接触区域中，我们首先从其呼叫地点移除了领地男性，并检查了某些颜色变身是否在这些现在空旷的地区更适合建立。然后，我们通过同时释放原住民和新住民到他们的俘获点来进行区域竞赛。令人惊讶的是，我们发现颜色对获得领土或赢得比赛没有重大影响。但是，在84％的分阶段比赛中，原住民赢得了新住民，显示出很强的先期居住权。O. pumilio。因此，与我们的假设相矛盾的是，仅男性-男性领地竞争似乎就不可能在该接触区域对颜色进行选择。