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| Map showing the Asian distribution, sampling localities, and population structure for the five taxa of the Asian Pied Starling (Gracupica contra) complex: nominate contra, sordida, superciliaris, floweri and jalla. in Baveja, Garg, Chattopadhyay, ... et Rheindt, 2021. |
Abstract
Urgent conservation action for terminally endangered species is sometimes hampered by taxonomic uncertainty, especially in illegally traded animals that are often cross‐bred in captivity. To overcome these problems, we used a genomic approach to analyze historical DNA from museum samples across the Asian Pied Starling (Gracupica contra) complex in tropical Asia, a popular victim of the ongoing songbird crisis whose distinct Javan population (“Javan Pied Starling”) is extinct in the wild and subject to admixture in captivity. Comparing genomic profiles across the entire distribution, we detected three deeply diverged lineages at the species level characterized by a lack of genomic intermediacy near areas of contact. Our study demonstrates that the use of historical DNA can be instrumental in delimiting species in situations of taxonomic uncertainty, especially when modern admixture may obfuscate species boundaries. Results of our research will enable conservationists to commence a dedicated ex situ breeding program for the Javan Pied Starling, and serve as a blueprint for similar conservation problems involving terminally endangered species subject to allelic infiltration from close congeners.
Keywords: Asian Pied Starling, Asian Songbird Crisis, conservation genetics, museum samples, South‐East Asia, target enrichment, wildlife trade
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| FIGURE 1: (a) Map showing the Asian distribution, sampling localities, and population structure for the five taxa of the Asian Pied Starling (Gracupica contra) complex: nominate contra, sordida, superciliaris, floweri and jalla. Black triangles depict wild sampling localities. Principal component analysis (PCA) is superimposed on the map with brown axes and based on an unlinked variant set of 936 SNPs (SNP set A2). STRUCTURE results are displayed as colored columns adjacent to collection localities (one column per individual) and are based on 412 unlinked SNPs (SNP set B2) at K = 3, with each color representing a different ancestral contribution. Legend depicts the color of PCA points (circles) and of distribution ranges (squares) for each taxon. Coastline map sourced from Natural Earth (www.naturalearthdata.com). Bird photo credits: contra—Mustafa Sozen, floweri—Peter Ericsson, jalla—Boas Emmanuel. (b) Maximum‐likelihood consensus trees based on (i) mitochondrial ND2 gene with bootstrap support ≥70% shown beside nodes and (ii) concatenated nuclear sequences of 117 loci (each with >12 SNPs per locus) with bootstrap support ≥95% shown beside nodes. GenBank accession numbers or sample codes are given behind each taxon name. (c) Pictures of superciliaris and floweri demonstrating differences in eye color and extent of bare facial skin across the two taxa. Photo credits: superciliaris—Thomas Brooks, floweri—Tom Wheatley |
Pratibha Baveja, Kritika M. Garg, Balaji Chattopadhyay, Keren R. Sadanandan, Dewi M. Prawiradilaga, Pramana Yuda, Jessica G. H. Lee and Frank E. Rheindt. 2021. Using Historical Genome‐wide DNA to Unravel the Confused Taxonomy in A Songbird Lineage that is Extinct in the Wild. Evolutionary Applications. DOI: 10.1111/eva.13149
