Biogeographic affinities of the Magpie-Robins and Shamas (Copsychus) of the Andaman Islands
National Center For Biological Sciences
Nelum Wickramasinghe*, V.V. Robin, Shushma Reddy & Uma Ramakrishnan
Introduction: What conservation problem or question does your study address?
The Andaman and Nicobar island arc in the Bay of Bengal stretches from southwestern Burma to northwestern Sumatra, which lies on the suture zone of the Indian and the Eastern Asian plates. Ornithogeographic affinities of the islands have been briefly studied in the past and receive high attention in present Indian biogeographic research. Using modern phylogenetic tools we intended to study the biogeographic affinities of the Magpie-Robins and Shamas of the Andaman Islands.
Methods: What were the main research methods you used?
Using mist nets, the two species found in the Andaman Islands, Copsychus saularis andamanensis (Oriental Magpie-Robin) and Copsychus albiventris (Andman Shama) were captured from the Andaman and Nicobar Environmental Team (ANET) campus in the South Andaman Islands. 3 samples from each species were captured, plumage characters were recorded, and feather samples were collected and preserved under -20°C. DNA was extracted using Qaigen extraction kit, PCR amplified for 3 mitochondrial genes (CO1 and ND2) and 1 nuclear gene (TGFβ2-5) and sequenced using Sanger sequencing method. Sequences for the 2 species from the neighbouring biogeographic regions were downloaded from GenBank, and all the sequences were multiple aligned with clustalW in Geneious 6.1.6. ML trees were generated using RaxML, using rapid bootstrap, for 1000 replicates with GTR+G model using Alethe diademata as the out group.
Results: What are your most important results?
Phylogenetic trees of Copsychua saularis for CO1 and ND2 indicate that the C.s. andamanensis closely related to the Singapore and Sumatran species. On the other hand C. albiventris has greatly diverged forming a separate clade.
Discussion: What are your important discussion points and what is the relevance of your results to conservation (if any)?
Even though distance wise the Andaman Islands are closer to Burma, C.s. andamanensis showing closer affinities to Sumatran and Singapore species come as a surprise. More detailed analysis needs to be done for a clearer conclusion.