AsianScientist (May 13, 2015) – An international team of scientists have discovered a new bird species in central China. The shy brown bird, named the ‘Sichuan bush warbler’, Locustella chengi, breeds in the mountainous region of the Sichuan Basin at an elevation of 1,000-2,300 meters. Their findings have been published in the journal Avian Research.
The bird is described as small, round-bodied, chocolate-brown colored, having a dark stubby tail, long pink legs, large dark eyes and a pointy black beak. Its English name refers to Sichuan province where it was first discovered. Its specific name, chengi, honors the late Professor Cheng Tso-hsin (1906-1998), one of China’s greatest ornithologists.
“I first heard this species together with my friend [Professor] Urban Olsson when we visited the sacred Emei mountain in Sichuan province, central China in May 1992,” said Professor Per Alström, a professor of systematics and evolution at Swedish University of Agricultural Sciences and lead author on this paper. Olsson is an associate professor of systematics and biodiversity at the University of Gothenburg and one of the many co-authors on this paper.
Alström said that what caught their attention was the unique sound that the bird produced, which was not very typical of a bird:
“We heard a song that was unfamiliar to us coming from a dense patch of tall herbs close to the trail. The song didn’t sound very ‘bird-like’ and as we couldn’t see a trace of any bird, we were debating for a little while whether it was a bird or some insect, although we thought it was most likely a bird,” recounted Alström.
More significantly, they noted that while it had the appearance of a russet bush warbler, Locustella mandelli, a species that they had both seen and heard in northwest Thailand, it produced a totally different call.
Following his return to China as a visiting professor at the Chinese Academy of Sciences, Alström and his Chinese colleagues Fumin Lei, Gang Song and Zuohua Yin from the Institute of Zoology at the Chinese Academy of Sciences in Beijing and Xuebin Gao from the Shaanxi Institute of Zoology in Xian set out to investigate. They found that the Sichuan bush warbler and the russet bush warbler both breed in the Qinling mountains and this provided the opportunity for a parallel comparison of both species.
Extensive analyses of the birds’ DNA, physical measurements, plumage color and vocalizations showed the differences between the species and confirmed their theory that the Sichuan bush warbler is a new species. For example, the Sichuan bush warbler’s breeding plumage is greyer overall, lacking the russet bush warbler’s strong russet tones.
In addition, the Sichuan bush warbler has a shorter tail and longer wings than the russet bush warbler. The Sichuan bush warbler also sings a lower-pitched song with more drawn out notes than the russet bush warbler. It is also noted that the two species breed at different elevations, with the Sichuan bush warbler nesting on lower mountainsides.
Further laboratory DNA analyses of samples from birds in the genus Locustella revealed that these two bush warblers are very closely related and that the two species diverged from a common ancestor roughly 850,000 years ago.
This discovery marks an advancement in documenting the undiscovered species of Earth’s organisms and adds further to the field of the evolution of birds.
Source: Chinese Academy of Sciences.
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