If a bird of one species is hatched and reared by a wholly different species, it is very apt when fully grown to prefer to mate with the species under which it has been reared. For example, a male passenger pigeon that was reared with ringdoves and had remained with that species was ever ready, when fully grown, to mate with any ringdove, but could never be induced to mate with one of his own species. I kept him away from ringdoves a whole season, in order to see what could be accomplished in the way of getting him mated finally with his own species, but he would never make any advances to the females, and whenever a ringdove was seen or heard in the yard he was at once attentive.²

²Whitman, C.O.n/an/an/an/a, "The Behavior of Pigeons," in , edited by H. Carr, 3: 28.