| The critically endangered Yellow-breasted Bunting has undergone population collapse globally because of illegal hunting and habitat deterioration.It was listed as critically endangered(CR)by the International Union for Conservation of Nature(IUCN)in 2017 and designated a Class I(highest level)national conservation bird species in China in 2021.Identifying the taxonomic status of subspecies or populations with independent evolutionary tendencies is important for the targeted conservation of endangered species.Birdsong is an important communication and recognition signal during the breeding season,and song variations have long been considered critical evidence of divergence among subspecies or populations.Two subspecies of the critically endangered,Yellow-breasted Bunting Emberiza aureola have long been classified: E.a.aureola and E.a.ornata.However,populations distributed in Hokkaido,Japan,are sometimes considered another subspecies of E.a.insulana.We compared the songs of 89 individuals from 18 populations to test subspecies taxonomy.We found that the analysis of multiple vocal traits supports the claim that insulana is distinct from aureola and ornata.By comparing vocal divergences,we found that insulana can be classified acoustically as a subspecies.Morphological and genetic differences should be tested further to confirm their subspecies status.Moreover,songs of the Yellow-breasted Bunting Emberiza aureola are subspecies specific and that three subspecies can be clearly discriminated by song divergences.Finally,at the geographic population level,populations can be clearly classified in accordance with the three subspecies,although the population in Xinjiang,the population in Sverdlovsk Oblast and the population in Khasyn,Magadanskaya Oblast,is differentiated from other populations of the same subspecies.The results of this study demonstrate that all populations and subspecies are unique and should be protected to maintain intraspecies song diversity.In addition,several specific populations,such as the insulana populations in Japan and the Xinjiang,China population of aureola,need to be paid special attention to prevent the extinction of unique or local taxa,especially in view of the disappearance of some Japanese populations.The results of this study not only confirm the subspecies status of E.a.insulana from the point of view of the song but also provide key evidence for targeted conservation efforts for this critically endangered bird species. |
