The early part of my scientific career was devoted to the study of motivation in animals. In the 1970s, I developed an interest in the excellent vision of birds and how visual information is processed in the avian central nervous system. This led to a series of anatomical experiments to determine the central visual pathways in the nervous systems of birds and application of various behavioral psychophysical techniques to measure color vision, visual acuity, luminance differences, and spatial and temporal contrast sensitivity in pigeons, quail, hawks, owls, starlings, and other birds. I have also carried out a number of studies of the physiological optics of the eyes of various birds. In addition to my research, I have scholarly interests in the evolution of the brain and the evolution of behavior, comparative neuroanatomy, and animal intelligence. I became an emeritus professor in 2005 and closed my laboratory. I therefore am no longer actively involved in research nor am I accepting new graduate students. I do, however, remain active in the teaching programs of the Psychology Department and the Neuroscience and Cognitive Science program