Data from: Fractured genetic connectivity threatens a southern California puma (Puma concolor) population

Pumas (Puma concolor; also known as mountain lions and cougars) in southern California live among a burgeoning human population of roughly 20 million people. Yet little is known of the consequences of attendant habitat loss and fragmentation, and human-caused puma mortality to puma population viability and genetic diversity. We examined genetic status of pumas in coastal mountains within the Peninsular Ranges south of Los Angeles, in San Diego, Riverside, and Orange counties. The Santa Ana Mountains are bounded by urbanization to the west, north, and east, and are separated from the eastern Peninsular Ranges to the southeast by a ten lane interstate highway (I-15). We analyzed DNA samples from 97 pumas sampled between 2001 and 2012. Genotypic data for forty-six microsatellite loci revealed that pumas sampled in the Santa Ana Mountains (n = 42) displayed lower genetic diversity than pumas from nearly every other region in California tested (n = 257), including those living in the Peninsular Ranges immediately to the east across I-15 (n = 55). Santa Ana Mountains pumas had high average pairwise relatedness, high individual internal relatedness, a low estimated effective population size, and strong evidence of a bottleneck and isolation from other populations in California. These and ecological findings provide clear evidence that Santa Ana Mountains pumas have been experiencing genetic impacts related to barriers to gene flow, and are a warning signal to wildlife managers and land use planners that mitigation efforts will be needed to stem further genetic and demographic decay in the Santa Ana Mountains puma population.

加利福尼亚南部的美洲狮（Puma concolor，俗称山狮、美洲金猫）栖息于人口规模约2000万的快速扩张的人类聚居区中。然而，针对伴随而来的栖息地丧失与破碎化、人类活动导致的美洲狮死亡，对美洲狮种群存续能力与遗传多样性所造成的影响，目前尚缺乏深入认知。本研究针对洛杉矶以南半岛山脉（Peninsular Ranges）内的沿海山地种群展开调查，采样区域涵盖圣迭戈、里弗赛德与橙县三地。圣安娜山脉（Santa Ana Mountains）的西、北、东三面均被城市化区域环绕，其东南侧与东部半岛山脉之间被一条十车道州际公路（I-15）分隔开。研究团队对2001年至2012年间采集的97份美洲狮DNA样本进行了分析。针对46个微卫星位点（microsatellite loci）的基因型数据分析显示：圣安娜山脉的采样个体（n=42）遗传多样性水平低于加州境内几乎所有其他受测种群（总样本量257只），其中包括I-15公路东侧紧邻的半岛山脉种群（n=55）。圣安娜山脉的美洲狮种群展现出较高的平均两两亲缘关系系数与个体内亲缘系数，估算有效种群规模偏低，且存在显著的种群瓶颈迹象，同时与加州其他种群存在遗传隔离。上述遗传与生态学研究结果清晰表明，圣安娜山脉的美洲狮种群正遭受基因流障碍带来的遗传负面影响；这一发现也为野生动物管理者与土地规划者敲响警钟：亟需采取缓解措施，以遏制圣安娜山脉美洲狮种群进一步出现遗传与种群数量衰退。