To ‘sing like a bird’ is to talk freely and fully when questioned, usually by the police, giving up information that implicates oneself or, more damagingly, other people. It is criminal slang rather than everyday English, carried over into general use mainly through crime fiction and film, where a suspect under pressure “sings” and names names. The phrase has a faintly contemptuous edge to it: the person who sings is often seen as weak or disloyal, breaking whatever code of silence was expected of them.
What’s the origin of the phrase ‘sing like a bird’?
The underlying idea, that talking under interrogation is a kind of “singing”, goes back a long way. Green’s Dictionary of Slang traces this use of “sing” to mean confessing as far back as 1687, in John Phillips’s English translation of Cervantes’s Don Quixote, in a passage that already plays on the word “Canary” alongside singing: “This, said he, is a Canary-Mere maid, that goes to the Gallies for having sung too much.” That pun on Canary, both the bird and a place name, shows the association between singing and confession was already well established by the late seventeenth century.
“Sing like a bird” itself was never coined as a separate phrase. Green’s Dictionary of Slang lists it as one of several interchangeable variants built on the same idea, alongside “sing like a canary”, “sing like a lark”, “sing like a nightingale”, “sing like the birds” and “trill like a canary”. Of these, “canary” is the dominant form in the written record. The earliest dated print citation Green’s Dictionary of Slang gives for this sense is from 1931, in W. N. Burns’s novel One-Way Ride: “A stool pigeon’s been squawking. That bird’s been singing like a canary lately.” That line also shows the connection between “singing” and the older slang term “stool pigeon” for an informer.
A crime-slang blog has claimed that “sing like a canary” first appeared in a 1935 book published by the Prevent Crime Bureau, written by Albin Jay Pollock. That date sits awkwardly alongside the 1931 citation already noted, so it cannot be treated as the confirmed first record. On the evidence available, the family of “sing” phrases built around birds was already current by the early 1930s, with roots in the much older pun on singing and canaries from the seventeenth century.