Genetic diversity and relative abundance of Cebu black shama (Copsychus cebuensis steere) in fragmented forests of Cebu Island, Philippines

Abstract

This study determined the relative abundance of Cebu black shama (Copsychus cebuensis Steere) in selected isolated forest fragments in Cebu Island, Philippines and their genetic diversity based on 619 bp cytB gene. Mist nets were used to capture the bird in these forest fragments. Four contour feathers were plucked from the body of the caught birds, before they were released, and were stored in tubes with 70% ethanol before DNA extraction. Fifty-nine black shama (C. cebuensis) individuals were encountered from the visited territories. At least 13 black shama individuals were estimated to inhabit one hectare of forest habitat. For the first time, analyses of mitochondrial genes revealed that C. cebuensis had a long evolutionary history from an initially large and stable population that went through recent expansion resulting from a recent isolating or bottleneck event as indicated by high haplotype diversity (Hd) and nucleotide diversity (πn), i.e. Hd>0.50 and πn>0.005, and non-significant values of Tajima’s D test, Fu and Li’s D*, and Fu’s Fs statistics. It is hypothesized that this bottleneck event was habitat fragmentation. Furthermore, phylogenetic analyses of C. cebuensis supported its monophyly.