Population genetic structure and conservation management of hill pigeons (Columba rupestris) recently endangered in South Korea

Abstract

Background Hill pigeons (Columba rupestris) are close to local extinction (ca. less than 100 individuals) in South Korea where a variety of conservation management procedures are urgently required. Objective This study was aimed at determining the conservation direction of captive propagation and reintroduction of hill pigeons using genetic information based on mitochondrial DNA. We also evaluated the extent of hybridization between hill pigeons and cohabiting domestic pigeons. Methods We used 51 blood samples of hill pigeons from Goheung (GH), Gurye (GR), and Uiryeong (UR), and domestic pigeons cohabiting with hill pigeon populations. Genetic diversity, pairwise Fst, analysis of molecular variance, and haplotype network analysis were used to examine the genetic structure of hill pigeons. Results Hill pigeons that inhabited South Korea were not genetically distinct from Mongolian and Russian populations and showed relatively low genetic diversity compared with other endangered species in Columbidae. The GR population that exhibited the largest population size showed lower genetic diversity, compared to the other populations, although the pairwise Fst values of the three populations indicated low genetic differentiation. The GH and GR populations were confirmed to lack hybridization, relatively, whereas the UR population was found to exhibit some degrees of hybridization. Conclusion To conserve hill pigeons with low genetic diversity and differentiation in South Korea, the conservation process of captive propagation and reintroduction may require artificial gene flows among genetically verified populations in captivity and wildness. The introduction of foreign individuals from surrounding countries is also considered an alternative strategy for maintaining genetic diversity.

Development of InDel markers for interspecific hybridization between hill pigeons and feral pigeons based on whole-genome re-sequencing

“…The tail pattern of F1 hybrids showed a clear tendency toward mixing the phenotypes of the two species, with the gray background of the feral pigeon’s traits and a rare white band of hill pigeon’s traits. This was consistent with the characteristics of individuals suspected to be hybrids using mtDNA in a previous study 36 .…”

“…Occasionally, feral pigeons invade man-made structures in forest areas where hill pigeons live, resulting in hybridization. Hybrids between feral pigeons and native populations in the Columbidae family have recently been reported in North America 42 and South Korea 36 . The hybrid markers that evolved throughout this complicated history were evaluated in this study.…”

“…Prior to experimental validation, we confirmed the phenotype of all individuals used in the experiment. All hill pigeons used in this study were collected from Gurey-gun and Goheung-gun in South Korea, where interspecific hybridization was not detected using mtDNA 36 , and the phenotype also reflected the characteristics of hill pigeons (Figs. S1 , S4 ).…”

“…Gene flow from feral pigeons to native populations has reduced the genetic originality of rock pigeons, leading to overlaps in morphology and behavioral ecology 35 . Furthermore, interspecific hybridization between two closely related species—feral pigeons and hill pigeons ( Columba rupestris )—has been reported in some regions, including in Northern India, Southern Siberia, and South Korea 36 , 37 . This is a cause for concern, as the hybridization has been accompanied by a loss of C. rupestris population 36 – 38 .…”

“…Furthermore, interspecific hybridization between two closely related species—feral pigeons and hill pigeons ( Columba rupestris )—has been reported in some regions, including in Northern India, Southern Siberia, and South Korea 36 , 37 . This is a cause for concern, as the hybridization has been accompanied by a loss of C. rupestris population 36 – 38 . However, the patterns and processes of interspecific hybridization between the two species remain unclear because of the lack of contemporary genomic tools 39 .…”