Visual fields of three diurnal raptors with the eyes at rest.

<p>Two views of the visual fields of Red-tailed Hawks (a, d), Cooper's Hawks (b, e), and American Kestrels (c, f). (a–c) Orthographic projection of the boundaries of the retinal fields of the two eyes, along with projection of the pectens and bill tips. A latitude and longitude coordinate system was used with the equator aligned vertically in the median sagittal plane. The bird's head is imagined to be at the center of the globe (grid is at 20° intervals). (d–f) Horizontal sections through the horizontal plane (90°–270°) showing the visual field configuration of each species. Each chart represents the average retinal visual field when the eyes were at rest. The dotted lines in the Cooper's Hawk representations (b, e) represent extrapolated binocular field assuming that the retinal margin follows a circular projection (see text).