Taxonomy of Pallas's Reed Bunting [i]Emberiza pallasi[/i] (Aves, Oscines, Emberizidae): An integrative approach

Abstract

The Pallas’s Reed Bunting Emberiza pallasi belongs to the Palearctic taiga forest clade of the family Emberizidae and breeds in the Ural Mountains to Kamchatka. In addition, a disjunct population occurs in Mongolia, with a slight range extension into Inner Mongolia (China) and southern Russia. Traditionally, E. pallasi is divided into three to four subspecies, among which the subspecies lydiae is considered the most distinct. According to the literature, this taxon differs from the others in call, song, ecology, behaviour, and some authors have even suggested elevating it to species rank. In this master’s thesis, I demonstrate that a deep genetic divergence exists between E. p. lydiae and E. p. pallasi/minor, based on two mitochondrial markers (COX1 and CYTB) and one nuclear marker (fib7), with a divergence time dating back to the early Pleistocene. I also confirmed differences in vocalizations between these two groups: both calls and songs differ significantly. Furthermore, the literature reports differences in habitat preferences, biometric traits and plumage traits. Using the General Lineage Concept (GLC), which defines a species as a segment of a lineage at the population level, these multiple lines of evidence indicate that E. p. pallasi/minor and E. p. lydiae form two distinct lineages following different evolutionary trajectories. This supports the hypothesis that E. p. lydiae should be treated as a distinct species.