Fig. 4. Young Great Horned Owl hatched in 1946. The two lower pictures show the developing facial mask. Photographs by João Moojen.
Fig. 5. Young Great Horned Owl hatched in 1946. Upper row: Ventral views showing scar of yolk sac and ventral side of wing. Middle row: Ventral (left) and dorsal view of wing at 21 days. Bottom row: Ventral (left) and dorsal view of wing at 47 days. Photographs by João Moojen.