
Photo: Ulf Johansson/Naturhistoriska riksmuseet · CC BY 3.0
Phylloscopus calciatilis
Habitat
Forest on limestone karst, 80–460 m
Range
Limestone karst of Laos and Vietnam; listed for China
Size
Smaller than the sulphur-breasted warbler
The limestone leaf warbler is a leaf warbler first seen in 1994 and mistaken for the similar sulphur-breasted warbler. It is smaller than that species, with more rounded wings and a proportionately longer bill, and its plumage is almost identical, with only a slightly colder yellow below and a greyer tinge above. (Wikipedia, general species account)
It is named for the limestone karst forests of Laos where it breeds. At Phong Nha-Ke Bang it was found in forest on the mountains between about 80 and 200 m, and at Hin Namno in old-growth and mature secondary semi-evergreen forest on karst between 280 and 460 m. The source does not describe its status in China. (Wikipedia, general species account)