Dataset and code for "Common-garden experiment reveals outbreeding depression and region-of-origin effects on reproductive success in a frequently translocated tortoise"

Data include nest site, hatching success and genetically-determined parentage data for clutches of gopher tortoises (Gopherus polyphemus) translocated to Nokuse, a private reserve in the panhandle of Florida. Human-mediated animal movement can expose wildlife populations to novel environments. Phenotypic plasticity can buffer against the challenges presented by novel environments, while adaptation to local ecosystems may limit resilience in novel ecosystems. Outbreeding depression during the mixing of disparate gene pools can also reduce reproductive success after long-distance movement. Here, we use a “common garden” population of gopher tortoises (Gopherus polyphemus), translocated from numerous sites across the state of Florida, USA, to a mitigation site in the northwest (panhandle) region to assess whether geographic origin, outbreeding effects, and behavioral plasticity influence reproductive success in this threatened keystone species. We found that females from northeast Florida produced clutches with lower hatching success than females from other regions. We detected regional differentiation in nest site selection behavior in the common environment of the translocation site, though these differences did not mediate the regional effect on hatching success. We also found evidence for outbreeding depression: hatching success declined with increasing parental geographic and genetic distances, dropping from 93% to 67% across the range of observed parental genetic distances. Together, these results suggest that newly admixed populations may suffer reproductive costs due to historic population differentiation, and that undetected outbreeding depression could significantly hamper conservation efforts for this species and others undergoing a variety of human-mediated movements.

本数据集包含挪库斯（Nokuse）私人保护区，位于佛罗里达州伸入墨西哥湾的半岛地区，移入的穴龟（Gopherus polyphemus）巢穴、孵化成功率以及基因决定的亲缘关系数据。人类介导的动物迁徙可能会使野生动物种群面临新的环境。表型可塑性可以缓冲新型环境带来的挑战，而适应本地生态系统可能限制了新型生态系统中的恢复力。在异种基因池混合过程中出现的远缘杂交衰退也可能降低长途迁徙后的繁殖成功率。本研究采用了一种“共同花园”式穴龟种群（Gopherus polyphemus），该种群源自佛罗里达州多个地点，并被移至西北部（半岛）地区的缓解场地，以评估地理起源、远缘杂交效应和行为可塑性是否会影响这一受威胁的关键物种的繁殖成功率。我们发现，来自东北佛罗里达州的女性产生的巢穴孵化成功率低于其他地区的女性。在移入场地的共同环境中，我们检测到巢穴选择行为存在区域差异，尽管这些差异并未调节区域对孵化成功率的影响。我们还发现了远缘杂交衰退的证据：孵化成功率随着父母地理和遗传距离的增加而下降，在观察到的父母遗传距离范围内，从93%降至67%。总之，这些结果表明，新混合种群可能因历史种群差异而遭受繁殖成本，并且未检测到的远缘杂交衰退可能会严重阻碍对该物种以及其他经历各种人类介导运动的物种的保护工作。