Avian (adjective, refers to birds)

Color vision (ability to distinguish objects based on the wavelengths of the light they reflect/emit)

Eye tracking (measure of the point of gaze or visual target; where an organism is looking)

Foraging (the act of searching for food)

Skull (bony skeleton of the head of vertebrates)

Visual acuity (ability to distinguish two objects as different within the visual field)

Visual fields (amount of space around the head from which visual information can be gathered)