Data from: Hybridization associated with cycles of ecological succession in a passerine bird

Identifying the diversity of contexts that can lead to hybridization is important for understanding its prevalence and dynamics in natural populations. Despite the potential of ecological succession to dramatically alter species co-occurrence and abundances, it is unknown whether it directly promotes hybridization and if so, has long-lasting consequences. Here, we summarize 30 years of survey data across ten populations to show that, in western and mountain bluebirds, heterospecific pairing occurs during repeatable and transient colonization events at the early stages of species turnover. Despite mixed pairing occurring during only early succession, genetic data showed presence of hybrids at both early and late successional stages. Moreover, hybrids showed novel patterns of variation in morphology and behavior emphasizing that even ephemeral contexts for hybridization can have important evolutionary consequences. Our results suggest that, because ecological succession often brings together closely related competitors in disparate numbers, but only lasts for a brief period of time, it may be a widespread but underappreciated context for hybridization.厘清可诱发杂交（hybridization）的各类情境类型，对于解析自然种群中杂交的发生频率与动态调控机制具有重要意义。尽管生态演替（ecological succession）具备显著改变物种共存格局与种群丰度的潜力，但目前仍不清楚其是否会直接促进杂交，若确实存在这种促进作用，其是否会带来长期演化后果。本研究整合了10个种群历时30年的调查数据，结果表明：在西蓝鸲（western bluebird）与山蓝鸲（mountain bluebird）中，种间配对（heterospecific pairing）发生于物种更替早期阶段可重复且短暂的拓殖事件中。尽管种间配对仅发生于早期演替阶段，但遗传数据分析显示，在演替早期与晚期阶段均存在杂交后代。此外，杂交后代在形态学与行为学层面展现出全新的变异模式，这充分说明即便仅存在于短暂情境中的杂交，也可能产生重要的演化后果。本研究结果表明：由于生态演替通常会将亲缘关系较近的竞争者以不均衡的种群数量聚集在一起，且演替过程仅持续较短时间，因此生态演替可能是一种广泛存在但尚未得到充分重视的杂交发生情境。