Eu fiz uma pequena pesquisa sobre essa questão e parece que o truque pode matar o canário, ou não, mas inevitavelmente resultou em muitas mortes de pássaros. Aqui está o aviso:
The vanishing bird trick (which, I regret to say, kills a great number of canaries) is performed by means of accessories in which the costume plays a part. The bird cage itself is made to collapse into a cigar shaped tube. The centre of the cigar shape is naturally fatter than the ends, and, if the bird is fortunate, it is secreted there and may come out of the ordeal alive. Should, however, the bird get at either end it is crushed to death, or should the legs get through the bars they are almost certain to be broken. A conjurer once told me he had done the trick 200 times with one bird, but I should very much doubt it. What happens is this. The bird cage is rapidly hooked to the end of a piece of whipcord, which passes up the sleeve and across the body of the performer, and then down the other sleeve, where it is tied to the wrist. It will thus be seen that the cord is considerably shorter than will be required to stretch from each end of the arms if they are extended. The cage, being in the performer's hand, is rapidly compressed and made to assume its cigar shaped form, and is dragged up the arm at lightning speed by the simple process of extending the two arms. This very simple trick has puzzled millions of people. It is performed so rapidly that even if you closely watch the conjurer I doubt if you will know what he is doing. Afterward the conjurer usually pretends to find the bird among the audience. As a matter of fact he takes another bird out of his pocket, and by one of the simple dodges of conjuring appears to take it from some one's neck or head, or some other convenient place. -- Current Literature 1893