Abstract:
Critically endangered Hooded Vultures (Necrosyrtes monachus Temminck, 1823), like many vulture species globally, are experiencing rapid population declines due to anthropogenic factors such as poisonings, human persecution, trading for belief-based use, and habitat loss/degradation. The Hooded Vulture is widespread across sub-Saharan Africa. Although it is considered one of the most abundant vultures in West Africa, this vulture species is less common in East and southern Africa, with the population at the southern-most edge of the distribution (in South Africa and Eswatini) estimated at only 100-200 mature individuals. The distribution of Hooded Vultures has contracted dramatically in southern Africa, with breeding populations largely confined to protected areas such as the Greater Kruger National Park. This study aimed to investigate the genetic diversity of the southern African range-edge population and assess if the recent contraction in the distribution has resulted in the population experiencing a genetic bottleneck. Sixteen microsatellite loci were amplified for samples collected along the Olifants River in the Greater Kruger National Park (n = 30). The genetic diversity in the South African population was compared to samples (n = 30) collected in Ghana, where Hooded Vultures are more abundant. Contrary to expectations, the South African peripheral Hooded Vulture population showed higher levels of heterozygosity (HO = 0.495) than the Ghanaian population (HO = 0.315). Neither population showed signs of recent bottleneck events when tested using demographic modelling and Approximate Bayesian computation (ABC). However, both populations showed high levels of inbreeding and relatedness. Our results suggest that despite being a small peripheral population, the South African Hooded Vulture population showed a similar level of genetic diversity as individuals sampled from a core population within the species distribution (in Ghana). This study supports the need for Hooded Vulture conservation efforts in the southern African region and highlights the evolutionary importance of range-edge populations.
摘要:
极度濒危的连帽秃鹰(NecrosyrtesmonachusTemminck,1823),像全球许多秃鹰一样,由于中毒等人为因素,人口正在迅速下降,人类迫害,交易基于信仰的使用,和栖息地的丧失/退化。带帽秃鹰在撒哈拉以南非洲很普遍。虽然它被认为是西非最丰富的秃鹰之一,这种秃鹰在东非和南部非洲不太常见,分布最南端的人口(南非和埃斯瓦蒂尼)估计只有100-200个成熟个体。在南部非洲,带帽秃鹰的分布急剧收缩,繁殖种群主要限于大克鲁格国家公园等保护区。这项研究旨在调查南部非洲边缘种群的遗传多样性,并评估最近的分布收缩是否导致种群经历遗传瓶颈。在大克鲁格国家公园(n=30)的Olifants河沿岸收集的样品中,扩增了16个微卫星基因座。将南非人口的遗传多样性与加纳收集的样本(n=30)进行了比较,连帽秃鹰更丰富。与预期相反,南非外围带帽秃鹰种群的杂合性水平(HO=0.495)高于加纳种群(HO=0.315)。在使用人口统计学建模和近似贝叶斯计算(ABC)进行测试时,两个人群均未显示出近期瓶颈事件的迹象。然而,这两个种群都表现出高水平的近亲繁殖和亲缘关系。我们的结果表明,尽管是一个小的外围人口,南非带帽秃鹰种群的遗传多样性水平与从物种分布中的核心种群采样的个体相似(在加纳)。这项研究支持在南部非洲地区进行连帽秃鹰保护工作的必要性,并强调了边缘种群的进化重要性。