Evolution of New Species of Songbirds: Implications for Biodiversity

Evolution of New Species of Songbirds: Implications for Biodiversity

Question : Western Ghats has evolved a new species of songbirds. Discuss its implications for biodiversity.

- A recent study found that the topography of Western Ghats is aiding the evolution of an upcoming species of songbirds

- Of the 23 species of songbirds inhabiting the tropical montane cloud shola forests across the Western Ghats, 10 have not crossed the Palghat valley for 1000 years

- Some specialist species have been isolated for up to 5 million years

- Many of the songbirds have become new species or sub species with genetic distinction according to researchers from the National Centre for Biological Sciences

- Data from more than 350 individual birds was taken across 3 years of fieldwork for this study

- At least 2 new species of short-wing and laughing thrust birds have displayed genetic diversity from other cousins

- As the valley is a barrier, population on either side is diverging into new species

- Apart from the genetic diversity, size of the bird as well as its sound and colour are accepted as new species by ornithologists globally

- Simulations indicate mountain top species diverged at different points in time ; while the two oldest species diverged 6.78 million years ago (Ma) and 4.84 Ma, the divergence time for the others were distributed from 2.5 Ma to less than 1 Ma.

Facts and Stats

- Misty peaks of the Western Ghats are known as sky islands at 1400m above sea level

- They are home to genetically diverse community of birds with around 23 species sharing the same habitat

- The Sky islands are interrupted by deep valleys which fragment habitat of the songbirds

- Unlike the Palghat valley, fewer species are affected by the Shenkottah and Chaliyar valleys of the Western Ghats