Ortolan Bunting

The ortolan is a Eurasian bunting, 16–17 cm long with a wingspan of 23–29 cm. In appearance and habits it much resembles the yellowhammer but lacks that species' bright colouring, its head being greenish-grey, and the song resembles the yellowhammer's. The source does not describe its status in China. (Wikipedia, general species account)

It is served in French cuisine, cooked and eaten whole, traditionally with the diner covering their head with a napkin. It was so widely eaten that French populations had dropped dangerously low by the 1990s. (Wikipedia, general species account)