Green’s Dictionary of Slang

1. a civilian dock worker in a military institution, e.g. a naval dockyard.

1961		Mad mag. Dec. 8: Yardbirds can blast butts and garbage clear off Army base.
1963		T. Pynchon V 427: ‘Yardbirds are the same all over,’ Pappy said [...] The dock workers fled by, jostling them.

2. anyone confined by authority to a restricted area, usu. prison; also attrib.

1944		P. Kendall Dict. Service Sl. n.p.: yard bird . . . soldier restricted to a limited area – a disciplinary measure.
1949		N. Algren Man with the Golden Arm 207: Yardbirds who couldn’t quite be trusted in a bakery or a laundry.
1953		L. Uris Battle Cry (1964) 45: You’re not like most of the yardbirds here.
1979		G. Wolff Duke of Deception (1990) 254: They knew my father was a yardbird, and they believed I was a Jew.
1988		D. Woodrell Muscle for the Wing 39: This led to frequent yardbird seminars on how we did this in Chicago, L.A., Boston, or Louisiana.
1989		H. Rawson Dict. of Invective (1991) 43: Because convicts are kept in cages, they are jailbirds (from the seventeenth century) as well as yardbirds (much newer, probably from the twentieth century).
1994		T. Willocks Green River Rising 133: They send in the National Guard, shoot ten or twenty of you yardbirds down.
2004		J. McCourt ‘Vilja de Tanquay Exults’ in Queer Street 303: A drag queen / Yard bird, old-lag ward of Her Majesty.
2010		IOL News (Western Cape) 27 Sept. 🌐 Y is for Yardbirds [who] took their name from a US jail slang term for prisoners in an exercise yard.

3. in fig use, one who is bound to another.

1965

C. Brown Manchild in the Promised Land (1969) 87: For the next two weeks K.B. was Claiborne’s yardbird. He had to go everywhere where Claiborne went.