Conjugate and Disjunctive Saccades in Contrasting Oculomotor Strategies’ Two Avian Species with

We have recorded with the magnetic search coil method the spontaneous saccades of two species of predatory birds, which differ in the relative importance of panoramic and fovea1 vision. The little eagle (Haliaetus morphnoides) hunts from great heights and has no predators, whereas the tawny frogmouth (Podargus strigoides) hunts from perches near the ground, is preyed upon, and frequently adopts an immobile camouflage posture. We find that both birds spend most of the time with their eyes confined to a small region of gaze, the primary position of gaze; in this position, the visual axes are much more diverged in the frogmouth than in the eagle, thereby giving it a larger total field of view at the expense of its binocular field. Both species, however, can align their visual axes