In birds, deep sympatric mtDNA   divergences have been found in a few species (e.g., Quinn 1992; Webb et al.   2011; Kerr et al. 2009b; Johnsen et al. 2010; Barrowclough et al. 2011). For   example, common ravens (Corvus corax)   show a 4% divergence between Holarctic and western North American lineages,   with a high degree of sympatry and interbreeding (Webb et al. 2011) and males   of the (Manacus manacus) collected from a single lek represented two groups   with 3.5% divergence (Kerr et al. 2009b). The interpretation of such deep   sympatric divergences is challenging and requires additional information   about potential methodological pitfalls in mtDNA sequencing and reproductive   barriers to gene flow in nuclear DNA.

在鸟类中，有些物种同域种群内线粒体DNA存在较高的分化（如Quinn 1992; Webb et al. 2011; Kerr et al. 2009b; Johnsen et al.   2010; Barrowclough et al. 2011）。例如，普通乌鸦（Corvus corax）在北极圈和北美西部血统之间表现出4%的差异，且具有高度的分布区重叠和杂交（Webb et al. 2011），从同一个求偶场采集的雄性白须娇鹟（Manacus manacus）代表着两个群组，差异为3.5%（Kerr et al. 2009b）。对这种同域差异的解释具有挑战性，也需要更多关于mtDNA测序中潜在的方法学缺陷和核DNA中基因流的生殖障碍的信息。