Blinking birds. Gannets are everywhere at Bempton Cliffs. I’m hoping to get a good look at their eyes. Gannets’ eyes are special.
This one has closed its eyelids. Most birds don’t have eyelids. Gannets do, because they hit the water head first at 60mph when they dive and that would damage them otherwise.
It’s one of several special adaptations they have to diving I described here:
This one has its eyelids open:
Then I see its third eyelid flick across. It moves from front to back. Its scientific name is a nictitating membrane.
The membrane moistens the eye and protects it from dust. Amazingly, in Gannets, it’s also see-through, so a Gannet can blink and still see through transparent eyelids. How cool is that?