Black-headed Bunting

The black-headed bunting is a 15 cm bunting, larger than a reed bunting and long-tailed, that breeds in open scrubby areas including agricultural land from south-east Europe east to Iran and migrates in winter mainly to India, some going further into south-east Asia. The source does not describe its status in China. (Wikipedia, general species account)

Adult males have yellow underparts, a chestnut back and a black head; in other plumages they are hard to separate from the closely related red-headed bunting, with which they hybridise where breeding ranges overlap. Males form pure flocks on migration and arrive in the winter quarters well before the females, and in winter they form large communal roosts in thorny acacia trees. The longest migration noted from a ringed bird is about 7,000 km. The clutch is four to six eggs. (Wikipedia, general species account)