Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen Ø, Denmark
Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen Ø, Denmark.
Proc Biol Sci. 2018 Mar 28;285(1875). doi: 10.1098/rspb.2017.2754.
Species traits are thought to predict feeding specialization and the vulnerability of a species to extinctions of interaction partners, but the context in which a species evolved and currently inhabits may also matter. Notably, the predictive power of traits may require that traits evolved to fit interaction partners. Furthermore, local abiotic and biotic conditions may be important. On islands, for instance, specialized and vulnerable species are predicted to be found mainly in mountains, whereas species in lowlands should be generalized and less vulnerable. We evaluated these predictions for hummingbirds and their nectar-food plants on Antillean islands. Our results suggest that the rates of hummingbird trait divergence were higher among ancestral mainland forms before the colonization of the Antilles. In correspondence with the limited trait evolution that occurred within the Antilles, local abiotic and biotic conditions-not species traits-correlate with hummingbird resource specialization and the vulnerability of hummingbirds to extinctions of their floral resources. Specifically, hummingbirds were more specialized and vulnerable in conditions with high topographical complexity, high rainfall, low temperatures and high floral resource richness, which characterize the Antillean Mountains. These findings show that resource specialization and species vulnerability to extinctions of interaction partners are highly context-dependent.
物种特征被认为可以预测物种对其相互作用伙伴灭绝的适应专化和脆弱性，但物种进化和目前生存的环境也可能很重要。值得注意的是，特征的预测能力可能需要特征是为适应相互作用伙伴而进化的。此外，当地的非生物和生物条件可能很重要。例如，在岛屿上，专门化和脆弱的物种主要被预测存在于山区，而低地的物种应该是普遍存在的，并且脆弱性较低。我们评估了安的列斯群岛上蜂鸟及其花蜜食物植物的这些预测。我们的研究结果表明，在安的列斯群岛殖民之前，祖先大陆形式的蜂鸟特征分歧率更高。与安的列斯群岛内发生的有限特征进化相对应的是，当地的非生物和生物条件——而不是物种特征——与蜂鸟资源特化以及蜂鸟对其花卉资源灭绝的脆弱性相关。具体而言，在地形复杂程度高、降雨量高、温度低和花卉资源丰富的条件下，蜂鸟的特化程度更高，更容易受到灭绝的影响，这些特征是安的列斯山脉的特点。这些发现表明，资源特化和物种对其相互作用伙伴灭绝的脆弱性高度依赖于环境。
