Interspersed with "sky islands" and large valleys, the unique topography of Western Ghats is aiding evolution of new species of songbirds, a recent study shows.
Of the 23 species of songbirds that inhabit the tropical montane cloud (shola) forests across Western Ghats, it was found that ten such species have not crossed the mighty 40-km-wide Palghat valley for several thousand years, with some specialist species isolated for even up to five million years.
"We were trying to understand how evolution happens over a very long period of time and have found that many of these songbirds have now become new species or sub-species with genetic distinction," researcher V V Robin of National Centre for Biological Sciences (NCBS) told PTI from Bengaluru.
He led a team of scientists from NCBS who collected genetic data from more than 350 individual birds across three years of fieldwork for the study.
Robin said they will soon propose at least two new species of shortwing and laughing thrust birds which have shown genetic diversity from their other cousins.
"If a valley is a barrier, populations on either side are genetically more different and begin to diverge, potentially into new species," he said.
Besides genetic diversity, the size of the bird, its sound, colour, etc are considered before it is accepted as a new species by ornithologists internationally.