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.