Data from: Ecological and evolutionary determinants for the adaptive radiation of the Madagascan vangas

Adaptive radiation is the rapid diversification of a single lineage into many species that inhabit a variety of environments or use a variety of resources and differ in traits required to exploit these. Why some lineages undergo adaptive radiation is not well-understood, but filling unoccupied ecological space appears to be a common feature. We construct a complete, dated, species-level phylogeny of the endemic Vangidae of Madagascar. This passerine bird radiation represents a classic, but poorly known, avian adaptive radiation. Our results reveal an initial rapid increase in evolutionary lineages and diversification in morphospace after colonizing Madagascar in the late Oligocene some 25 Mya. A subsequent key innovation involving unique bill morphology was associated with a second increase in diversification rates about 10 Mya. The volume of morphospace occupied by contemporary Madagascan vangas is in many aspects as large (shape variation)—or even larger (size variation)—as that of other better-known avian adaptive radiations, including the much younger Galapagos Darwin's finches and Hawaiian honeycreepers. Morphological space bears a close relationship to diet, substrate use, and foraging movements, and thus our results demonstrate the great extent of the evolutionary diversification of the Madagascan vangas.

适应性辐射（Adaptive radiation）是指单一支系快速分化为多个物种的演化过程，这些物种栖息于多样环境、利用各异资源，并具备适配这些生存策略的性状差异。尽管目前对于为何部分支系会发生适应性辐射仍缺乏清晰认知，但占据未被利用的生态位似乎是其普遍特征。我们构建了马达加斯加特有钩嘴鵙科(Vangidae)的完整、经时间校准的物种水平系统发育树。这一雀形目鸟类辐射类群属于经典却鲜为人知的鸟类适应性辐射类群之一。本研究结果显示，该类群于渐新世晚期、距今约25 Mya时定居马达加斯加后，其演化支系数量与形态空间分化均出现了初期快速增长。此后，一项涉及独特喙部形态的关键创新，与距今约10 Mya时的第二次分化速率增长存在关联。现生马达加斯加钩嘴鵙类所占据的形态空间体积，在诸多方面与其他知名度更高的鸟类适应性辐射类群相当（形状变异维度），甚至在体型变异维度上更为广阔——这些类群包括更为年轻的加拉帕戈斯群岛达尔文雀（Galapagos Darwin's finches）与夏威夷旋蜜雀（Hawaiian honeycreepers）。形态空间与食性、栖息基质利用以及觅食行为存在紧密关联，因此本研究结果证实了马达加斯加钩嘴鵙类的演化分化程度之高。