Area of Ecology and Biodiversity, School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong SAR.
Committee on Evolutionary Biology, University of Chicago, Chicago, IL, USA.
Mol Biol Evol. 2024 Nov 1;41(11). doi: 10.1093/molbev/msae222.
Many highly recognizable species lack genetic data important for conservation due to neglect over their hyperabundance. This likely applies to the Sulfur-crested Cockatoo (Cacatua galerita), one of the world's most iconic parrots. The species is native to Australia, New Guinea, and some surrounding Melanesian islands of the latter. Four subspecies are currently recognised based on morphology. Australian subspecies and populations are abundant, but several factors threaten those in New Guinea and Melanesia. Genetic data from natural populations are scarce-information that is vital to identifying evolutionarily significant units (ESUs) important for modern conservation planning. We used whole-genome resequencing to investigate patterns of differentiation, evolutionary affinities, and demographic history across C. galerita's distribution range to assess whether currently recognised subspecies represent ESUs. We complement this with an assessment of bioacoustic variation across the species' distribution landscape. Our results point to C. galerita sensu lato (s.l.) comprising two species. We restrict C. galerita sensu stricto (s.s.) to populations in Australia and the Trans-Fly ecodomain of southern New Guinea. The second species, recognised here as Cacatua triton, likely occurs over much of the rest of New Guinea. Restricting further discussion of intraspecific diversity in C. triton, we show that within C. galerita s.s. two ESUs exist, which align to Cacatua galerita galerita in eastern Australia and southern New Guinea and Cacatua galerita fitzroyi in northern and north-western Australia. We suggest that the evolution of these species and ESUs are linked to Middle and Late Pleistocene glacial cycles and their effects on sea level and preferential habitats. We argue that conservation assessments need updating, protection of preferential forest and woodland habitats are important and reintroductions require careful management to avoid possible negative hybridization effects of non-complementary lineages.
许多高度可识别的物种由于过度丰富而缺乏对保护很重要的遗传数据。这可能适用于葵花凤头鹦鹉（Cacatua galerita），这是世界上最具标志性的鹦鹉之一。该物种原产于澳大利亚、新几内亚和后者的一些周围美拉尼西亚岛屿。目前根据形态学识别出四个亚种。澳大利亚亚种和种群丰富，但一些因素威胁着新几内亚和美拉尼西亚的亚种。来自自然种群的遗传数据稀缺——对于确定对现代保护规划很重要的进化意义上的单位（ESU）至关重要。我们使用全基因组重测序来研究 C. galerita 分布范围内的分化模式、进化亲缘关系和种群历史，以评估目前公认的亚种是否代表 ESU。我们还评估了该物种分布景观中的生物声学变异。我们的研究结果表明，C. galerita 广义（s.l.）由两个物种组成。我们将 C. galerita 狭义（s.s.）限制在澳大利亚和新几内亚南部的跨飞生态区的种群中。第二种，即 Cacatua triton，可能分布在新几内亚的大部分地区。我们进一步限制了对 C. triton 种内多样性的讨论，表明在 C. galerita s.s. 中存在两个 ESU，它们与澳大利亚东部和新几内亚南部的 Cacatua galerita galerita 以及澳大利亚北部和西北部的 Cacatua galerita fitzroyi 相对应。我们认为这些物种和 ESU 的进化与中更新世和晚更新世的冰川周期及其对海平面和偏好栖息地的影响有关。我们认为需要更新保护评估，保护偏好的森林和林地栖息地很重要，重新引入需要谨慎管理，以避免可能出现的非互补谱系的负面杂交效应。
