Data from: Genetic evidence for high propagule pressure and long-distance dispersal in monk parakeet (Myiopsitta monachus) invasive populations

The monk parakeet (Myiopsitta monachus) is a successful invasive species that does not exhibit life history traits typically associated with colonizing species (e.g., high reproductive rate or long-distance dispersal capacity). To investigate this apparent paradox, we examined individual and population genetic patterns of microsatellite loci at one native and two invasive sites. More specifically, we aimed to evaluate the role of propagule pressure, sexual monogamy, and long-distance dispersal in monk parakeet invasion success. Our results indicate little loss of genetic variation at invasive sites relative to the native site. We also found strong evidence for sexual monogamy from patterns of relatedness within sites, and no definite cases of extra-pair paternity in either the native site sample or the examined invasive site. Taken together, these patterns directly and indirectly suggest that high propagule pressure has contributed to monk parakeet invasion success. In addition, we found evidence for frequent long-distance dispersal at an invasive site (~100km) that sharply contrasted with previous estimates of smaller dispersal distance made in the native range (~2km), suggesting long-range dispersal also contributes to the species' spread within the United States. Overall, these results add to a growing body of literature pointing to the important role of propagule pressure in determining, and thus predicting, invasion success, especially for species whose life history traits are not typically associated with invasiveness.

和尚鹦鹉（Myiopsitta monachus）是一种成功的入侵物种，却未表现出通常与入侵定居物种相关的典型生活史特征（life history traits）（例如高繁殖率或长距离扩散能力）。为探究这一表观悖论，我们对1个原生分布地与2个入侵分布地的微卫星（microsatellite）位点的个体及种群遗传模式展开了分析。具体而言，本研究旨在评估繁殖体压力（propagule pressure）、单配制以及长距离扩散在和尚鹦鹉入侵成功中的作用。研究结果显示，相较于原生分布地，入侵分布地的遗传多样性损失极小。我们还通过种群内的亲缘关系模式找到了支持单配制的有力证据，且在原生分布地样本与所研究的入侵分布地样本中均未发现明确的婚外父权（extra-pair paternity）案例。综合来看，这些模式直接或间接表明，高繁殖体压力助力了和尚鹦鹉的入侵成功。此外，我们在一处入侵分布地发现了频繁长距离扩散的证据（扩散距离约100公里），这与此前在原生分布区估算的更小扩散距离（约2公里）形成鲜明对比，提示长距离扩散同样推动了该物种在美国境内的扩散。整体而言，本研究结果进一步充实了日益增长的相关学术文献，表明繁殖体压力在决定乃至预测入侵成功方面发挥着重要作用，这一点对于那些生活史特征通常不具备入侵性的物种而言尤为如此。