New Himalayan bird species found by listening to its unique voice
Himalayan Forest Thrush: Scientists first discovered a new species of bird in northeastern India not by DNA analysis or physical differences, but by their prettier songs.
Himalayan Forest Thrush, or the Zoothera salimalii.
Per Alstrom
An international team of scientists has discovered a new species of bird by studying the musicality of its song.聽
鈥淭here aren鈥檛 too many new birds to be found in the world,鈥� lead author Per Alstrom told the BBC. 鈥淪o it鈥檚 exciting when you find a new one.鈥澛�
In a study published in the current issue of Avian Research journal, a team of scientists from Sweden, China, the US, India and Russia explain how they discovered the Himalayan forest thrush Zoothera salimali species, named after the Indian ornithologist Salim Ali.聽
Researchers have been analyzing the discovery since 2009, when they suspected the plain-backed thrush Zoothera mollissima, a small bird that lives in northeastern India, was actually two different species.聽
鈥淲hat first caught scientists鈥� attention was the plain-backed , whereas individuals found in the same area 鈥� on bare rocky ground above the treeline 鈥� had a much harsher, scratchier, unmusical song,鈥� explain the authors in a press release.聽
Scientists studied , analyzing duration, mean frequency and frequency bandwidth.聽
鈥淭he song of the Himalayan Forest Thrush sounds much more musical and 鈥榯hrush-like鈥� than that of the Alpine Thrush,鈥� the scientists write in their paper. 鈥淚t is built up of a mix of rich, drawn-out clear notes and shorter, thinner ones, .鈥澛�
And 鈥渁lthough their songs are fairly similar, ,鈥� say scientists, adding to evidence that they are different species.
The scientists also studied the two species鈥� morphology and DNA sequencing 鈥� but that was only to confirm what the birds鈥� songs first revealed.聽
鈥淭he had 鈥� to us 鈥� . We couldn鈥檛 at first find any differences in plumage or structure between them,鈥� Alstrom tells the BBC.聽
In fact, the researchers studied museum specimens of the presumed single species for years, trying to recognize physical differences.聽
鈥淎t first we had no idea how or whether they differed morphologically,鈥� Pamela Rasmussen, from Michigan State University鈥檚 Department of Integrative Biology and author of the study, said in a press release. 鈥� from the same parts of the Himalayas could readily be divided into two groups based on measurements and plumage.鈥澛�
The scientists suspect that the Himalayan forest thrush and Alpine thrush began as one species and then evolved into two distinct populations to cope with their very different habitats. The Himalayan forest thrush has shorter legs and a shorter tail, 鈥渨hich . Because longer legs are more useful in open habitats than in forest,鈥� says Alstrom.
Alstrom also discovered a sub-species of India鈥檚 new Himalayan forest thrush that lived in China, and named it the . DNA analysis suggests that these three species 鈥� although recently discovered 鈥� have actually been genetically different for millions of years.
The Himalayan forest thrush is the fourth new bird species to be discovered in India since the country鈥檚 independence in 1947. And since 2000, a global average of have been discovered each year, the majority in South America.聽