Page:American Journal of Psychology Volume 21.djvu/73

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INTELLIGENCE AND IMITATION IN BIRDS
63

For the 4th trial following this change the strings were placed on the rear at the right corner. There now occurred a fortunate conjunction of circumstances more than once which has given me my best results on the subject of imitation in birds. Instead of opening the door as I meant for him to do, Young Crow 1, after about a dozen efforts, put the beak through the wire just to the right of the door in front and pulled one of the strings running vertically from the latch to the under surface of the top of the box, Fig. 21. The door opened and following his playful habit he jumped to the top

Fig. 22

Young Crow 1 at his favorite play with the box. He was swinging on the door. When he jumped off the door usually closed and he or the Old Crow must open again. This is important for it brings the tests in rapid succession, a very favorable condition for imitation.

of the door and swung back and forth a few times, Fig. 23. In hopping off the door, as he always did in a few seconds, he closed it and thus made possible another test at once after Jim had seen him open the door from in front. In spite of the fact that Jim had shown strong inclination to go to the left end, he now made most of his thirty efforts on the front and really succeeded in opening the door in the same way as the young one had done. In the next trial Jim opened by two hard blows on the door itself, for I had placed the strings so that they could not be reached through the wire.

For the following trial I had changed the box so that the door did not open so easily by striking against it. However, Jim struck it fifteen times and the Young Crow 1 outwitted me again by pure accident in lifting the door up when his claws extended over the edge of the box and caught in the upper