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 10 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 only during 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 lasts for only a brief period of time, it may be a widespread but underappreciated context for hybridization.明确各类可引发杂交（hybridization）的情境类型，对于理解自然种群中杂交的发生频率与动态演化机制至关重要。尽管生态演替（ecological succession）能够显著改变物种的共存模式与种群丰度，但目前仍不清楚其是否会直接促进杂交，若确实如此，是否会产生长期演化后果。本研究汇总了10个种群历时30年的调查数据，结果显示：在西蓝鸲与山蓝鸲中，异种配对（heterospecific pairing）发生于物种更替（species turnover）早期阶段可重复且短暂的定殖事件期间。尽管异种配对仅出现于早期演替阶段，但遗传数据表明，在演替早期与晚期阶段均存在杂交个体（hybrids）。此外，杂交个体展现出形态与行为层面的全新变异模式，这凸显出即便仅存在于短暂情境中的杂交事件，也可能产生重要的进化后果。本研究结果表明：由于生态演替通常会使数量悬殊的近缘竞争者聚集在一起，且演替过程仅持续较短时长，因此生态演替可能是一种广泛存在但尚未被充分认识的杂交发生情境。