- In 2009, researchers observed that there seemed to be two different kinds of “plain-backed thrushes” in northeastern India.
- They discovered that the “plain-backed thrush” found in the coniferous forests of northeastern India and adjacent parts of China (now called the Himalayan forest thrush) had a strikingly different, and more musical and thrush-like song than that of the “plain-backed thrush” found on bare rocks, above the tree line (now called the Alpine thrush).
- The researchers named the tuneful Himalayan Forest Thrush Zoothera salimalii in honor of Dr Sálim Ali (1896–1987), for “his huge contributions to the development of Indian ornithology and conservation.”
For a long time, birders called it the plain-backed thrush (Zoothera mollissima).
But in 2009, researchers observed that there seemed to be two different kinds of “plain-backed thrushes”. On listening closely, they discovered that the “plain-backed thrush” found in the coniferous forests of northeastern India and adjacent parts of China (now named the Himalayan forest thrush) had a strikingly different song than that of the “plain-backed thrush” found on bare rocks, above the tree line (now called the Alpine thrush).
The song of the Alpine thrush sounds very unmusical, Per Alström of Uppsala University in Sweden, and his colleagues, write in a paper published in the journal Avian Research. The Alpine thrush’s song has a mainly “rasping, grating, scratchy, cracked voice and a few squeaky, clearer notes admixed,” they add.
In contrast, the song of the Himalayan forest thrush is made up of a “mix of rich, drawn-out clear notes and shorter, thinner ones, with hardly any harsh scratchy notes”, which sounds more musical and “thrush-like” than that of the Alpine thrush, the authors write.
“To an ornithologist, the Himalayan forest thrush sounds like Adele, while the alpine thrush sounds more like Rod Stewart,” co-author Shashank Dalvi, an alumnus of a masters in wildlife biology and conservation run by the Wildlife Conservation Society and National Centre for Biological Sciences, said in a statement.
The researchers named the tuneful Himalayan forest thrush Zoothera salimalii in honor of Dr Sálim Ali (1896–1987), for “his huge contributions to the development of Indian ornithology and conservation.”
The Himalayan forest thrush is not a rare bird, scientists say. The bird is locally common, they add, but overlooked until now “because of its close similarity in appearance to the Alpine thrush.”
New bird discoveries in India are rare, though. The Himalayan forest thrush is only the fourth new bird species to be discovered in India since the country’s independence in 1947, the researchers say.
Analysis of plumage, structure, song, DNA and ecology of the “plain-backed thrushes” throughout their range, has revealed that central China could be home to a third species of the “plain-backed thrush”, now called the Sichuan forest thrush.
The results of the DNA analyses suggest that the Alpine thrush, the Himalayan forest thrush and the Sichuan forest thrush genetically separated several million years ago.
Citation:
- Alström P, et al (2015) Integrative taxonomy of the Plain-backed Thrush (Zoothera mollissima) complex (Aves, Turdidae) reveals cryptic species, including a new species. Avian Research doi:10.1186/s40657-016-0037-2