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Genetic study settles debate on classification of endangered owlet

Scientists have finally determined the genera of Forest Owlet with the help of genetic data and cleared the century old confusion about its classification. So far the classifications based on morphological characteristics and anatomical data had placed the small owls of Asia alternatively into Athene, Glaucidium, and Heteroglaux genera.

A team of researchers from multiple institutes in India collaborated to conduct genetic data analysis of Heteroglaux blewitti for the first time to show that the owlet nested in the Athene group. The paper published in PLOS One used mitochondrial and nuclear combined datasets to conduct the first ever genetic analysis of the critically endangered forest owlet.

H. blewitti, endemic to India, has been a taxonomic mystery since its discovery in 1872 with the species placed into three genera, namely, Athene, Glaucidium, and Heteroglaux,  though none of these classifications were based on a formal phylogenetic analysis. To remove this confusion, the scientists with the support of the Department of Biotechnology analysed genetic data from feathers and broken egg shells of the birds. This analysis of genetic data was compared with that of the three different groups. Six loci (location of a gene) were sequenced and phylogenetic analyses of owlets were carried out. Sequence analyses, laboratory procedures, phylogenetic reconstruction and molecular dating analysis, confirmed the results.

Phylogenetics refers to the evolutionary relationships between various species based upon the similarities or differences in their physical or genetic characteristics. These relationships are discovered through phylogenetic inference methods that evaluate observed heritable traits, such as DNA sequences. The ecology and phylogenetic history of endangered species are crucial to understand the features that are vital for their conservation and may affect the policy-level decisions regarding species conservation.

The research team consisted of scientists from several institutes in India and abroad namely Salim Ali Centre for Ornithology & Natural History at Coimbatore (TN), Manipal Academy of Higher Education at Manipal (KA), Indian Institute of Science Education and Research at Tirupati (AP), Wildlife Research and Conservation Society at Pune (MH), National Centre for Biological Science, TIFR, at Bangalore (KA), Karnataka and Loyola University, Chicago (United States of America).

Although the new information on the phylogenetic status of the bird does not directly impact the IUCN status of the species, it’s ranking in international conservation listings that use phylogenetic information may change. The Evolutionary Distinct and Globally Endangered (EDGE) listing will perhaps no longer carry the same evolutionary distinctness score for the species. The study provides the first genetic dataset of H. blewitti and can facilitate the taxonomic revision of the Athene/ Heteroglaux clade.

Endemic and endangered species are often ecologically specialized and their classification on the basis of morphological and anatomical characteristics may create confusions. There is an urgent need to better understand the ecology and phylogenetic history of endangered species to uncover features that might be crucial for conservation. Such species could be viewed as model species to understand evolutionary processes in the landscape of their occurrence. However, our knowledge of the evolutionary history of highly restricted, endemic species in the tropics is limited, due to their rarity and incomplete genetic sampling. This could have far-reaching consequences on policy level decisions regarding species conservation.  

This research emphasizes on the urgent need for studies predicting species responses to climate change to address the pressing issue of species conservation.  This first molecular phylogenetic study of the Critically Endangered species, also demonstrates that crucial information can only be obtained through capture-based sampling that strengthens and supports ecological data collected through conventional methods. Principal Investigator: Dr. Shomita Mukherjee  (shomitam@gmail.com)

Dr. Archita Bhatta and Dr. Chhavi Gupta