Afghanistan (B), Bangladesh, Brunei Darussalam, Cambodia, China (mainland), India, Indonesia, Japan, Kazakhstan (B), Laos, Malaysia, Myanmar, Nepal, North Korea, Pakistan, Philippines, Russia (Asian), Russia (Central Asian) (B), Singapore, South Korea, Thailand, USA, Vietnam.
Dark-sided Flycatcher (Muscicapa sibirica) [XC672355]
by Oriental Stork from Cape Nanhui, China (call)
Dark-sided Flycatcher (Muscicapa sibirica) [XC486372]
by Stanislas Wroza from Murino, Slyudyansky District, Irkutskaya oblast', Russian Federation (flight call, song)
Subspecies
Geographical variation not well marked. In southern Asia there is a cline of increasing darkness of upperparts from west to east, many individuals not assignable to subspecies, and the recognition of more than one taxon (gulmergi and cacabata) from this area is questionable.
The following 4 subspecies are recognised:
sibirica Gmelin, 1789 - Breeds central and south-eastern Siberia (east to Kamchatka), north-eastern Mongolia, north-eastern China (south to Nei Mongol, northern Liaoning and Jilin), northern Korea and Japan. Non-breeding Taiwan, southern China (Guangxi, Guangdong, southern Fujian), Indochina and northern Borneo.
cacabata Penard, TE, 1919 - Breeds central and eastern Himalayas east to southern China (southern Xizang), Bhutan and north-eastern India (Assam hills). Non-breeding southern Myanmar and southern Thailand.
rothschildi (Baker, ECS, 1923) - Breeds central and southern China (south-eastern Qinghai, south-eastern Gansu and southern Shaanxi south to eastern Xizang and Sichuan), northern and western Myanmar and north-western Vietnam. Non-breeding southern China (south-eastern Yunnan east to Guangdong), Indochina, Malay Peninsula and Sumatra.
BirdLife International Species Factsheet