It is well worth our while to note that this series and all that follow in the present paper were made on the birds in out-door wire cages most of which were ten feet square by six high. The conditions were very much more natural if they do not always give such uniform results as may be obtained by working on birds kept in the laboratory. Inside one can control the food supply as well as other conditions so that the birds are more hungry and undisturbed; but it is probably better to sacrifice nice uniformity for naturalness.
This series was really a Memory one for the Junco, the interval being some half a month. During this interval with three Cowbirds this bird was carried several hundred miles from the laboratory in Worcester, Mass., to Shawnee-on-Delaware, Pa., and placed in very different surroundings. The Whitethroated Sparrow had found its way into a wire cage at Mr. Worthington's Pheasantry, and was captured and placed in this cage. Its size and disposition, and ability to fight account for its early successes and for the long times even when the Junco opened the door. The White-throated Sparrow would not allow any of the birds to come near the box. This was not true for the first of the Junco's trials and it will be seen from the table that they were good. The short time of the Junco in the seventh trial, its first success, indicates that previous to this the White-throated Sparrow and the strange surroundings served to keep it away from the box.
The White-throated Sparrow, if we make an exception of her earlier trials, may be said to have opened the door in the manner used by the Junco. But she did not long continue this. She jumped up on the post rather than on the string. At times her efforts were as many as seventy-two and ninety-two, and largely for the reason that her efforts had to do with the post and not with the string, Fig. 14. This method was used habitually, and points to the kind of associations of which this bird was capable.
For the 129th test the food was shifted to the left side of the door, and in the next to the left rear corner. This was done with many of the birds in order to see whether it would lead them away from the strings, and cause them to work on another part of the box which was very similar in appearance to that where the strings were placed first. This change had no effect at this time, but after this bird and the Song Sparrow were transferred to another cage, such a change in the place of the food did have quite a disturbing effect. See tests 159, 160 and
but also in many other respects. My acknowledgments are gratefully made to Mr. Chas. W. Miller, Director of the Society, and to Mr. W. H. Montgomery for carrying on experiments during the writer's enforced absence, as well as for many other services.
Journal–3
