Translocation of conspecific individuals to reduce extinction risk of small, isolated populations and prevent genetic depletion is a powerful tool in conservation biology. An important question is how the translocated individuals influence the long-term genetic composition of the recipient population. Here, we experimentally reinforced a house sparrow (Passer domesticus) population, and examined the impact of this translocation on allele frequencies, levels of heterozygosity and genetic differentiation over six cohorts. We found no permanent increase in the mean number of alleles across loci or levels of observed heterozygosity, but a few alleles private to the translocated individuals remained in the population and we found a short-term increase in heterozygosity. Consequently, genetic differentiation of the recipient population compared to the genetic composition prior to reinforcement was small. The limited genetic impact was due to combined effects of a small probability of establishment and low mating success for the translocated individuals, together with increased genetic drift in the recipient population. Our findings emphasize the importance of selection and genetic drift as forces that may decrease the genetic contribution of reinforcement, especially in small populations. Conservation managers should aim to improve habitat quality in the recipient population to reduce genetic drift following translocation and thereby avoid the need for continued reinforcement. Furthermore, by facilitating establishment success and selecting individuals expected to have high mating success, possibly indicated by sexually selected traits, genetic contribution of released individuals is increased which in turn will decrease reproductive skew and genetic drift.

转移特定个体以减少小而孤立的种群灭绝的风险并防止遗传耗竭是保护生物学的有力工具。一个重要的问题是，易位个体如何影响接受者群体的长期遗传组成。在这里，我们通过实验加固了一只麻雀（Passer domesticus）人群，并检查了该易位对六个队列中等位基因频率，杂合水平和遗传分化的影响。我们没有发现每个基因座的平均等位基因数目或所观察到的杂合水平的永久增加，但是在种群中仍然存在一些对易位个体私有的等位基因，并且我们发现杂合度的短期增加。因此，与强化前的遗传组成相比，受体群体的遗传分化很小。有限的遗传影响是由于易位个体成立概率低，交配成功率低以及受助者群体遗传漂移增加的综合影响。我们的研究结果强调了选择和遗传漂移的重要性，因为它们可能会降低增强基因的遗传贡献，尤其是在少数人群中。保护管理者应致力于改善接收者种群的栖息地质量，以减少易位后的遗传漂移，从而避免持续加固的需要。此外，通过促进建立成功并选择可能具有高交配成功率的个体（可能由性选择的性状表明），释放的个体的遗传贡献增加，这反过来将减少生殖偏斜和遗传漂移。保护管理者应致力于改善接收者种群的栖息地质量，以减少易位后的遗传漂移，从而避免持续加固的需要。此外，通过促进建立成功并选择可能具有高交配成功率的个体（可能由性选择的性状表明），释放的个体的遗传贡献增加，这反过来将减少生殖偏斜和遗传漂移。保护管理者应致力于改善接收者种群的栖息地质量，以减少易位后的遗传漂移，从而避免持续加固的需要。此外，通过促进建立成功并选择可能具有高交配成功率的个体（可能由性选择的性状表明），释放的个体的遗传贡献增加，这反过来将减少生殖偏斜和遗传漂移。