How Did a Sponsee get to Be Called a"Pigeon"?

The word "pigeon" used to denote a newcomer appears to have come from Dr. Bob, our Akron, Ohio co-founder. According to the reference to "pigeon" in DR. BOB & The Good Oldtimers, it was being used as early as 1940

John S., who joined A.A. in January 1940, thought his A.A. friend Wade was nuts. "He'd pick up the phone and say, 'How are you? ... All right. How's your pigeon?' And that was the end of the conversation. I thought he had telephonitis. But he was just keeping in touch.

(Incidentally, the word "pigeon"--as applied to an A.A.newcomer or prospect--was probably coined by Dr. Bob himself. "Heused that word," said Smitty, and one A.A. recalled that Doc wouldoften announce at a meeting: "There's a pigeon in Room so-and-so whoneeds some attention.'" Or he might refer to the patient as "acookie.")

(DR. BOB and the Good Oldtimers, p.146