Bhatt Supriya, Biswas Suvankar, Karanth Krithi, Pandav Bivash, Mondol Samrat
Animal Ecology and Conservation Biology, Wildlife Institute of India, Dehradun, India.
Centre for Wildlife Studies, Bengaluru, India.
PeerJ. 2020 Feb 4;8:e8482. doi: 10.7717/peerj.8482. eCollection 2020.
Large carnivores maintain the stability and functioning of ecosystems. Currently, many carnivore species face declining population sizes due to natural and anthropogenic pressures. The leopard, , is probably the most widely distributed and highly adaptable large felid globally, still persisting in most of its historic range. However, we lack subspecies-level data on country or regional scale on population trends, as ecological monitoring approaches are difficult to apply on such wide-ranging species. We used genetic data from leopards sampled across the Indian subcontinent to investigate population structure and patterns of demographic decline.
We collected faecal samples from the Terai-Arc landscape of northern India and identified 56 unique individuals using a panel of 13 microsatellite markers. We merged this data with already available 143 leopard individuals and assessed genetic structure at country scale. Subsequently, we investigated the demographic history of each identified subpopulations and compared genetic decline analyses with countrywide local extinction probabilities.
Our genetic analyses revealed four distinct subpopulations corresponding to Western Ghats, Deccan Plateau-Semi Arid, Shivalik and Terai region of the north Indian landscape, each with high genetic variation. Coalescent simulations with microsatellite loci revealed a possibly human-induced 75-90% population decline between ∼120-200 years ago across India. Population-specific estimates of genetic decline are in concordance with ecological estimates of local extinction probabilities in these subpopulations obtained from occupancy modeling of the historic and current distribution of leopards in India.
Our results confirm the population decline of a widely distributed, adaptable large carnivore. We re-iterate the relevance of indirect genetic methods for such species in conjunction with occupancy assessment and recommend that detailed, landscape-level ecological studies on leopard populations are critical to future conservation efforts. Our approaches and inference are relevant to other widely distributed, seemingly unaffected carnivores such as the leopard.
大型食肉动物维持着生态系统的稳定性和功能。目前，由于自然和人为压力，许多食肉动物物种面临种群数量下降的问题。豹可能是全球分布最广、适应性最强的大型猫科动物，仍在其大部分历史分布范围内生存。然而，我们缺乏国家或区域尺度上关于种群趋势的亚种水平数据，因为生态监测方法难以应用于如此广泛分布的物种。我们利用从印度次大陆各地采集的豹的基因数据来研究种群结构和种群数量下降模式。
我们从印度北部的特莱 - 弧景观中收集粪便样本，并使用一组13个微卫星标记鉴定出56个独特个体。我们将这些数据与已有的143个豹个体的数据合并，并在国家尺度上评估遗传结构。随后，我们调查了每个已识别亚种群的种群历史，并将遗传下降分析与全国范围内的局部灭绝概率进行比较。
我们的基因分析揭示了与西高止山脉、德干高原 - 半干旱地区、西瓦利克和印度北部景观的特莱地区相对应的四个不同亚种群，每个亚种群都有很高的遗传变异。对微卫星位点的溯祖模拟显示，大约在120 - 200年前，印度各地可能由于人类活动导致种群数量下降了75 - 90%。特定种群的遗传下降估计与通过对印度豹的历史和当前分布进行占有率建模获得的这些亚种群的局部灭绝概率的生态估计一致。
我们的结果证实了一种分布广泛、适应性强的大型食肉动物的种群数量下降。我们重申了间接遗传方法与占有率评估相结合对于此类物种的相关性，并建议对豹种群进行详细的景观水平生态研究对于未来的保护工作至关重要。我们的方法和推断与其他分布广泛、看似未受影响的食肉动物如豹相关。
