Page:American Journal of Psychology Volume 21.djvu/65

Rh

Intelligence and Imitation in Crows as Determined by Tests in Opening the Food-box.

The old Crow, Jim, with which my first work on Crows began had been in possession of Mr. Worthington for some five or six years. His wings had been clipped and most of the time he was to be found in some part of the large lawn. For a year or more he had been confined to a large wire cage. He was very wary. Even an acquaintance must exercise care in pulling Jim's beak or scratching his head for at such times he was apt to use his bill with painful results.

It should be added that the sex of this bird as well as that of the young crows was not known. If they are referred to as males it is only in an impersonal way and analogous to what we do with many other animals as well as inanimate objects.

On rare occasions Jim could be induced to swell himself up very much and apparently with the greatest effort give utterance to something which sounded like a muffled "Hello." The presence of ladies seemed to furnish a stimulus better calculated to call forth this one expression Jim's whole vocabulary. I could more frequently induce him to imitate me in saying this word by having a white towel in my hand. It seemed to me that the ladies wearing white could best get Jim to show off his one accomplishment.

As remarked above Jim was most cautious and wary. Any new object placed in his cage he was most slow to make use of. How then was I to determine how rapidly he could learn to open my food-box. I began with him somewhat gradually. On the twelfth of June I made a box like that shown in Fig. 21. To begin with I left off the door as well as the wire from the left end and front of the box. Would Jim eat from the pan placed just inside the door? Not a bit of it. When his foodsupply was abundant he always hid all that he could not eat. It was hardly ever possible, therefore, to know exactly when you had cut off his supply. Yet in this case I had to coax him nearer and nearer the box by placing the pan well in front and by degrees nearer. Finally I starved him into approaching near enough to stand on tip-toe, stretch his neck, and very suddenly take a bit of food from the pan inside. As an extra inducement I often placed in the pan half a hen's egg of which he seemed to be very fond. With each addition of wire, door, or strings he had to be given time to overcome a new lot of caution.

On July twenty-fourth, about six weeks after I first placed the box inside the cage, my first test was made. The box with door closed was placed in at 2.31 P. M. After forty trials, which