do 是“做，干”，bird 是“鸟”，do bird 可不是 “做鸟，干鸟”的意思，而是“坐牢、服刑”。

【例句】
After doing bird for the past five years, Mark is getting released from jail today.
马克在监狱服刑了五年，今天就要出狱了。

He has done bird for 10 years due to his crime.
因为他犯的罪，他在牢里蹲了10年。