If pigeons recognize objects using local features alone, then variations in the arrangement of those features would have little or no impact on the accuracy of recognition. Thus, unlike humans, the pigeon would be incapable of discriminating between the cup and the pail. The cup and the pail are comprised of two components: a cylinder and a curved handle. However, the orientation and position of the handle relative to the cylinder differs between the objects. In order to discriminate the cup from the pail, one must be able to recognize the differences in the organization of the components, a more global property of objects. Several experiments by Kirkpatrick-Steger, Wasserman, and Biederman have demonstrated that pigeons can discriminate changes in spatial organization, and that spatial organization plays a key role in picture recognition in pigeons. There is, however, one difference in the local features of the cup and pail -- the points of contact (intersections) between the handle and cylinder differ slightly. If pigeons were attentive to fine variations in local features (as PFT argues), then the differences in contact pionts could prove sufficient in differentiating between these objects. Kirkpatrick-Steger, Wasserman, and Biederman (1998) ruled out the contribution of the contact points as a significant contributor to object recognition in pigeons.