About Seicercus castaniceps (Hodgson, 1845)
The chestnut-crowned warbler, currently classified as Phylloscopus castaniceps, is a species of leaf warbler in the family Phylloscopidae. It was formerly grouped into the broader "Old World warbler" assemblage, and was previously placed in the genus Seicercus under the scientific name Seicercus castaniceps (Hodgson, 1845). A molecular phylogenetic study published in 2018 found that neither the genus Phylloscopus nor Seicercus were monophyletic. In the taxonomic reorganization that followed, the two genera were merged into Phylloscopus, which has priority under the rules of the International Commission on Zoological Nomenclature. This species is found in Bangladesh, Bhutan, Cambodia, China, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Thailand, and Vietnam. Its natural habitats are subtropical or tropical moist lowland forest, and subtropical or tropical moist montane forest. Nine subspecies are recognized across its range, and it forms a superspecies with the Sunda warbler and the yellow-breasted warbler. It is arboreal and primarily insectivorous. Though it is not considered migratory, it may make small seasonal movements to higher or lower elevations.
