A new bird that is highly secretive has been discovered in China, thanks to its distinctive song.
The Sichuan bush warbler resides in five mountainous provinces in central China and is a close relative of the Russet bush warbler.
It has shunned the limelight by hiding in grassy, scrubby vegetation over the years.
"The Sichuan bush warbler is exceedingly secretive and difficult to spot as its preferred habitat is dense brush and tea plantations," said Pamela Rasmussen, integrative biologist, assistant curator at the Michigan State University Museum and co-author of the discovery shared in Avian Research.
"However, it distinguishes itself thanks to its distinctive song that consists of a low-pitched drawn-out buzz, followed by a shorter click, repeated in series."
The bird does not appear to be under any imminent threat, says Rasmussen who has helped document and scientifically describe 10 new species of birds.
The bird's signature song can be found on MSU's Avian Vocalizations Center website.
The Sichuan and Russet warblers can be found on some of the same mountains with the Sichuan bush warbler preferring lower elevations.
The Sichuan bush warbler breeds up to 7,500 feet.
The two warblers also share many genes. Analyses of mitochondrial DNA show they are closely related and had a common ancestor around 850,000 years ago.
The Sichuan bird's Latin name, Locustella chengi, honours the late Cheng Tso-hsin, China's famed ornithologist.
"We wanted to honour Professor Cheng Tso-hsin for his unparalleled contributions to Chinese ornithology," Rasmussen said. "Many species are named for European explorers and monarchs but few bear the names of Asian scientists."
Warblers are small perching birds and feed on insects. There are known to be two families of warblers across the globe -- the family Parulidae in the New World (all over Americas) and the family Silviidae in Old World (Europe, Asia, Africa and Australia).
In all, there are 438 species of warblers.
Recently, the blackpoll warbler recorded one of the longest over-water flights covering between 1,410 and 1,721 miles in just two to three days.