Abstract
Revealing the genetic population structure in abundant avian species is crucial for understanding speciation, conservation, and evolutionary history. The Red-backed Shrike Lanius collurio, an iconic songbird renowned for impaling its prey, is widely distributed as a breeder across much of Europe, Asia Minor and western Asia. However, in recent decades, many populations have declined significantly, as a result of habitat loss, hunting along migration routes, decrease of arthropod food, and climate change e.g., severe droughts in Africa. Within this context, gene flow among different breeding populations becomes critical to ensure the survival of the species, but we still lack an overview on the genetic diversity of the species. In this paper, we analyzed the mitochondrial cytochrome b gene (mtDNA) and the cytochrome c oxidase subunit 1 gene (mtDNA) of 132 breeding Red-backed Shrikes from across the entire breeding range to address this knowledge gap. Our results revealed consistent genetic diversity and 76 haplotypes among the Eurasian populations. Birds are clustered in two major groups, with no clear geographical separation, as a direct consequence of Pleistocene glaciations and apparent lineage mixing in refugia. This has led to genetic panmixia.
Highlights
Quaternary cold periods have greatly shaped the evolution and distribution of present biota worldwide [1], and this is evident in the northern temperate regions [2]
During the Pleistocene era—starting 2.5 million years ago and ending just 11,000 years before present—the climate in northern temperate regions was characterized by dramatic oscillations, commonly known as “glaciations” [3,4], each of them lasting anywhere between 21,000 to 100,000 years [5]
After the retreat of the ice cap, populations expanded and recolonized the northern latitudes [8,9]. This complex process of post-glacial population expansion northward from the southern refugia occurred at least 30 times during the Pleistocene [3] and was in strong interdependence with the vegetation availability [10]
Summary
Quaternary cold periods have greatly shaped the evolution and distribution of present biota worldwide [1], and this is evident in the northern temperate regions [2]. During the Pleistocene era—starting 2.5 million years ago and ending just 11,000 years before present—the climate in northern temperate regions was characterized by dramatic oscillations, commonly known as “glaciations” [3,4], each of them lasting anywhere between 21,000 to 100,000 years [5]. These severe glacial episodes forced biota to retreat to southern refugia [6,7], which implied admixing of populations. It was only after the emergence of molecular techniques and their wide application in zoology that the history of post-glaciation colonization and its impact on the genetic structure of European biota really unfolded [13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
