The bird's eye contains a nictitating membrane which is a translucent, semitransparent inner eyelid. It sweeps across the surface of the eye enabling the bird to blink without losing sight of or without blocking their view.
Birds also have two different tear glands. One type of tear gland is located along the lower eyelid while the other is located at the base of the nictitating membrane. The second tear gland lubricates the bird's eyes whenever the nictitating membrane blinks.
Blood pressure by many hormones like ADH , renin etc !
Explanation:
Great white sharks are blue-gray on the dorsal, or top, part of their bodies. This helps them blend in with the bottom of the ocean when viewed from above. The belly, or ventral, part of the body, is white. This makes it difficult to see the sharks from below, with sunlight shining in around them.
I just answered your other post with these questions. (:
Answer:
overproduction (not overpopulation there is a correction there)
