Vision

What is the dominant sense for birds?

Birds' eyes are very large relative to body size. What is the importance of this?

What are the four special features of the avian eye?

What is the sclerotic ring?

What does the ability for birds to vary the curvature of the cornea allow for?

What is the nictitating membrane?

What is the pecten?

What is the retina?

What are three similarities between bird and mammal retinas?

What are three differences between bird and mammal retinas?

What are foveae?

What is the function of central foveae?

What is the function of temporal foveae?

How many foveae do birds typically have?

What is a field of vision?

What allows for birds to have a large visual field?

What trade-off allows for most birds to have a large monocular field of vision?

What allows for birds to have well-developed colour vision?

What are carotenoid pigments?

What four carotenoid pigments do diurnal birds have?

What two carotenoid pigments do nocturnal birds have?

What results in birds have tetrachromatic colour vision?

What is the purpose of birds being sensitive to ultraviolet light?