True story - I never knew birds had eyelids

Dear Board,

I'm being honest. I've taken thousands of bird pictures and in every last one of them the bird had it's eyes wide open.

That changed today when I caught perhaps my favorite bird blinking as it ate a suet feeder.

Regards,

Tim Murphy
Harrisburg, PA

I'll bet that suet cake doesn't last very long.

It's called a nictitating membrane, and not only birds have them.

Dear lycomech,

They last longer than you think and pileated woodpeckers are quite resourceful.

Last weekend I'll bet this same woodpecker had the suet feeder completely enveloped. It's feet were at the top of the cage and it was slung underneath and craning it's neck to get to the suet. That bird got ever little last bit it could.

Regards,

Tim Murphy
Harrisburg, PA

Dear Ohlook,

Thanks for the explanation!

Regards,

Tim Murphy
Harrisburg, PA

OhLook wrote in post #18298502
It's called a nictitating membrane, and not only birds have them.

Not only do they have the third eyelid (nictitating membrane). They have eyelids like us. I've caught many birds in a blink, especially hummingbirds.

Birds do have normal eyelids, as well as a nictitating membrane, just like us they blink and close their eyes to sleep. However they can sleep with just one eye closed, whilst resting one half of the brain, and still watch out for danger with the other eye. When that side of the brain has had enough sleep they can switch sides. When they don't feel threatened they can sleep normally with both sides at once.

Great comment and info on this thread. Here is a picture I took a couple years back that provides a comparison. If I am not mistaken the young female is blinking her upper and lower eyelid as opposed to the nictitating membrane which is somewhat translucent and sweeps in horizontally. Someone please correct me if I am wrong.

grizzerbear wrote in post #18299138
Great comment and info on this thread. Here is a picture I took a couple years back that provides a comparison. If I am not mistaken the young female is blinking her upper and lower eyelid as opposed to the nictitating membrane which is somewhat translucent and sweeps in horizontally. Someone please correct me if I am wrong.

I'm not sure about blinking, but her eye does look partly closed. The membrane also seems to cover it. That eye is dull, not shiny like her nestmate's eye.