ABSTRACT Phylogeographic studies of northern Australian birds frequently detect the influence of the Carpentarian Barrier in vicariantly structuring present-day genetic variation. Several barriers further west (e.g. Canning Barrier), and, where data are available, the Arafura Sea and Torres Strait separating Australia and New Guinea have an overall lesser effect. Using sequence data from mitochondrial (mtDNA) and nuclear DNA, we tested whether the Blue-winged Kookaburra (Dacelo leachii), widespread in monsoonal northern Australia and southern New Guinea, shows evidence of vicariance by these barriers. Viewed in phylogenetic context of other Australo-Papuan kookaburras (D. novaeguineae, D. gaudichaud, D. tyro), clear phylogeographic subdivisions were absent within the range of D. leachii. Subspecies groupings explained a significant amount of molecular variance within D. leachii, the most distinct being New Guinean D. l. intermedia. Genealogical relationships among mtDNA haplotypes suggest a recent connection between New Guinea and Western Australia, a history recently proposed for at least one other bird species of similar open woodland habitat. Species distribution modelling similarly indicated that climatic conditions during the last glacial maximum (LGM) may have facilitated a connection between New Guinea and present-day Western Australia along the exposed Arafura shelf, and that suitable conditions remained continuous across the Carpentarian Barrier during the LGM. This work adds to a growing body of data on population genetic structuring of Australia’s birds in relation to biogeographic barriers and it is the first such analysis of a large-bodied, non-passerine bird having an extensive geographic range in tropical and subtropical Australia and New Guinea.

中文翻译：

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横跨热带澳大利亚北部和新几内亚的蓝翅笑翠鸟的系统地理学

摘要 澳大利亚北部鸟类的系统地理学研究经常发现卡彭特里亚屏障在替代构建当今遗传变异中的影响。更西边的几个障碍（例如坎宁障碍），以及在有数据的情况下，分隔澳大利亚和新几内亚的阿拉弗拉海和托雷斯海峡总体上影响较小。使用来自线粒体 (mtDNA) 和核 DNA 的序列数据，我们测试了广泛分布于澳大利亚北部和新几内亚南部季风带的蓝翅笑翠鸟 (Dacelo leachii) 是否显示出这些屏障的替代证据。从其他 Australo-Papuan 笑翠鸟（D. novaeguineae、D. gaudichaud、D. tyro）的系统发育背景来看，在 D. leachii 的范围内不存在清晰的系统地理细分。亚种分组解释了 D. leachii 内的大量分子变异，最明显的是新几内亚 D. l. 媒体。mtDNA 单倍型之间的谱系关系表明新几内亚和西澳大利亚之间最近存在联系，最近提出的至少一种其他类似开放林地栖息地的鸟类的历史。物种分布模型类似地表明，上次冰期盛期 (LGM) 期间的气候条件可能促进了新几内亚和今天西澳大利亚沿着暴露的阿拉弗拉大陆架之间的联系，并且在 LGM 期间，合适的条件在整个卡彭特里亚屏障中保持连续。