Data from: Using genetic tools to estimate the prevalence of non-native red deer (Cervus elaphus) in a Western European population

Game species like the red deer have been subjected to anthropogenic impacts for centuries. Translocations are often carried out—sometimes illegally—not only for sporting purposes, but also to increase trophy quality, reduce inbreeding, or mitigate bottlenecks after excessive persecution. Apart from the blurring of large-scale genetic structure, translocations without adequate quarantine measure risk introducing pathogens into potentially immunologically naïve populations. It is therefore important to understand the frequency of clandestine translocations. Identification of non-autochthonous animals and their potential origin is often difficult and, in red deer, has been hampered by the lack of large-scale genotypic datasets for comparison. In the present study, we make use of a recently published European-wide microsatellite dataset to detect and quantify the presence of non-autochthonous red deer in a large population sample (n = 1,780) from Central Europe (Belgium). Using factorial correspondence analysis, assignment tests and Bayesian clustering algorithms we arrive at an estimate of 3.7% non-autochthonous animals (or their descendants). Some of these animals were assigned to a nearby French population and may have immigrated into Belgium naturally, but the large majority must have been introduced by humans. Our analysis pointed to the British Isles and Germany/Poland as the potential origin of many introduced deer, regions known to have been source populations for translocations in Europe and beyond. We found evidence for recreational hunters using carcasses from farmed deer to fulfill mandatory hunting quotas. Our study is the first to quantify the extent of human-mediated introductions in a European game species at such a large scale with large and representative sample sizes.

数个世纪以来，马鹿（red deer）这类猎用野生动物长期受到人为活动的影响。种群易地释放（translocation）行为时有发生，其中不乏非法操作；其实施目的不仅限于狩猎活动本身，还包括提升狩猎战利品品质、降低近交衰退风险，或是缓解因过度猎杀引发的种群瓶颈效应。除了会破坏种群的大尺度遗传结构外，未采取充分检疫措施的易地释放行为，还可能将病原体引入原本缺乏相应免疫能力的种群中。因此，摸清秘密易地释放行为的发生频率显得尤为关键。甄别非原生个体及其潜在来源地往往难度颇高，而针对马鹿的相关研究更因缺乏可用于比对的大尺度基因型数据集而进展受阻。本研究借助近期公开的欧洲全域微卫星（microsatellite）数据集，对采自中欧比利时的大型种群样本（n = 1,780）中的非原生马鹿个体进行检测与量化分析。通过因子对应分析、个体归属测试及贝叶斯聚类算法，本研究估算出该样本中非原生马鹿（及其后代）的占比为3.7%。其中部分个体被归类至邻近的法国种群，推测其可能是自然迁入比利时，但绝大多数个体应是人为引入的。分析结果显示，不列颠群岛及德国/波兰是多数引入鹿群的潜在来源地，这些区域历来是欧洲乃至全球范围内种群易地释放的种源地。本研究还发现，休闲狩猎者会利用养殖鹿的尸骸来完成法定狩猎配额。本研究首次以大样本量且具有代表性的种群样本，对欧洲猎用物种中人为介导的物种引入规模进行了量化分析。