Genetic diversity and population structure of two endangered neotropical parrots inform In Situ and Ex Situ conservation strategies

<b>Abstract</b><br/><p><p>A key aspect in the conservation of endangered populations is understanding patterns of genetic variation and structure, which can provide managers with critical information to support evidence-based status assessments and management strategies. This is especially important for species with small wild and larger captive populations, as found in many endangered parrots. We used genotypic data to assess genetic variation and structure in wild and captive populations of two endangered parrots, the blue-throated macaw, Ara glaucogularis, of Bolivia, and the thick-billed parrot, Rhynchopsitta pachyrhyncha, of Mexico. In the blue-throated macaw, we found evidence of weak genetic differentiation between wild northern and southern subpopulations, and between wild and captive populations. In the thick-billed parrot we found no signal of differentiation between the Madera and Tutuaca breeding colonies or between wild and captive populations. Similar levels of genetic diversity were detected in the wild and captive populations of both species, with private alleles detected in captivity in both, and in the wild in the thick-billed parrot. We found genetic signatures of a bottleneck in the northern blue-throated macaw subpopulation, but no such signal was identified in any other subpopulation of either species. Our results suggest both species could potentially benefit from reintroduction of genetic variation found in captivity, and emphasize the need for genetic management of captive populations.</p></p>

摘要<br/>濒危种群保护的核心环节之一是解析遗传变异与群体结构模式，此类信息可为管理者提供关键依据，支撑基于实证的种群现状评估与保护管理策略制定。对于野生种群规模较小、圈养种群规模较大的物种而言，这一点尤为关键，诸多濒危鹦鹉类群均属于此类情况。本研究借助基因型数据，对两种濒危鹦鹉的野生与圈养种群开展遗传变异与群体结构分析：分别是分布于玻利维亚的蓝喉金刚鹦鹉（Ara glaucogularis），以及分布于墨西哥的厚嘴鹦鹉（Rhynchopsitta pachyrhyncha）。针对蓝喉金刚鹦鹉，研究发现其野生北部与南部亚种群之间，以及野生种群与圈养种群之间仅存在微弱的遗传分化。对于厚嘴鹦鹉，未检测到Madera与Tutuaca两个繁殖种群之间，亦或野生种群与圈养种群之间存在遗传分化信号。两种鹦鹉的野生与圈养种群均检测到相近水平的遗传多样性；两类群的圈养种群中均发现了特有等位基因，厚嘴鹦鹉的野生种群中同样存在特有等位基因。研究在蓝喉金刚鹦鹉北部亚种群中检测到种群瓶颈的遗传特征，但在两种鹦鹉的其余亚种群中均未发现此类信号。本研究结果表明，通过引入圈养种群的遗传变异可对两类群产生潜在增益，同时强调了对圈养种群开展遗传管理的必要性。