10/18/2026
Zombie Bird, or Nictitating Membrane?
I've done a post before about a very cool thing with birds and other animals, but raptors especially. They have a translucent eyelid that serves several purposes. It not only lubricates the eyes, but it protects them too while allowing them to see while flying. Raptors pursue it prey sometimes through areas like woods or grasses and bushes that could potentially scratch their eyes. The translucent membrane allows them to see while maneuvering around obstacles. I can't time the exposures to capture it as it can open and close quickly, but when I do get lucky enough to capture it, I always process the image for later use. I think sometimes it can make the bird look like a zombie, but a cool zombie at that! In this image if you zoom in you can see the veins that run through the membrane! For this image I used the Tamron 50-400mm Di III E mount lens. My settings for the image were at 400mm on a Sony a1, Manual Mode, f8, shutter speed of 1/500th of a second, ISO 2000, handheld, f-stop Gear Kashmir AIR backpack. Tamron Americas Teton Raptor Center