Africa’s montane ecosystems are noteworthy not only for their isolation but for their morphologically similar bird populations that inhabit geographically disparate localities. Many species possess range disjunctions in excess of 2,000 km and appear to represent populations that have been isolated since at least the last Ice Age, including the Northern Double-collared Sunbird (Cinnyris reichenowi). Recent work on other Afromontane birds has demonstrated substantial phylogeographic structure can exist in phenotypically similar populations, with cryptic species occurring parapatrically within the same mountain range. We explored genetic, morphological, and ecological diversity within C. reichenowi to assess whether cryptic regional diversification occurs across the disjunct portions of this species’ range. Within C. reichenowi, we find consistent patterns of morphological disparity that coincide with genetic diversification between xeric and wet montane populations within the Cameroon Line in the Western population, and clear genetic differentiation between Western and Eastern populations. Our research demonstrates that the geographically isolated populations of C. reichenowi represent different species, and that ecological diversification is shaping populations within Central Africa. We show here that two named populations should be recognized as members of a western species in the Northern Double-collared Sunbird complex: nominate Cinnyris preussi preussi in the Cameroon Line montane forests, and Cinnyris preussi genderuensis in the more xeric interior of Cameroon and the Central African Republic, likely occurring in adjacent Nigeria as well.

中文翻译：

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多条证据表明非洲山地太阳鸟（Cinnyris reichenowi）正在进行异域和旁域多样化

非洲的山地生态系统值得注意，不仅因为它们与世隔绝，还因为它们栖息在地理上不同地区的形态相似的鸟类种群。许多物种拥有超过 2,000 公里的范围分离，并且似乎代表了至少自上一个冰河时代以来就已被隔离的种群，包括北方双领太阳鸟 (Cinnyris reichenowi)。最近对其他非洲山地鸟类的研究表明，在表型相似的种群中可以存在大量的系统地理结构，在同一山脉中出现隐蔽的物种。我们探索了 C. reichenowi 内的遗传、形态和生态多样性，以评估神秘的区域多样化是否发生在该物种范围的分离部分。在 C. reichenowi 内，我们发现一致的形态差异模式与喀麦隆线西部种群中干旱和潮湿山地种群之间的遗传多样化相吻合，以及西方和东方种群之间的明显遗传分化。我们的研究表明，地理上孤立的 C. reichenowi 种群代表不同的物种，生态多样化正在塑造中非的种群。我们在这里展示了两个命名的种群应该被认为是北部双领太阳鸟复合体中的一个西方物种的成员：在喀麦隆线山地森林中提名 Cinnyris preussi preussi，在喀麦隆和中部更干旱的内陆地区提名 Cinnyris preussi genderuensis非洲共和国，也可能发生在邻近的尼日利亚。