Examples of Bird's Third Eyelid - The Nictitating Membrane by Todd Henson

Female red-winged blackbird with third eyelid, the nictitating membrane, closed over eye.

Female red-winged blackbird looking normal with eye open.

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One of the great things about photographing wildlife is the opportunity to see aspects of the animals you might not normally see, and then to later research and learn about that aspect of the animal. An example of this is the nictitating membrane on birds. The nictitating membrane is a third eyelid under the typical two eye lids we all have. It’s a translucent eyelid that can be closed while the other eyelids are open to clean and protect the eye. If you own a cat you might have seen an example of this, as cats also have nictitating membranes.

Eastern Phoebe with eye wide open.

Small portion of third eyelid showing on Eastern Phoebe.

Tim Birkhead, in his fantastic book, Bird Sense: What It’s Like to Be a Bird, says knowledge of this additional eyelid has existed for centuries. People such as Aristotle, Frederick II, and Louis XIV wrote about it. Frederick II wrote in his falconry manual: "for cleaning the eyeball there is provided a peculiar membrane that is quickly drawn across its anterior surface and rapidly withdrawn." John Ray and Francis Willughby wrote in their 1678 encyclopedia of birds,  "Most, if not all birds, have a membrane of nictation... where withal they can at their pleasure cover their eyes, though the eyelids be open... and serves to wipe, cleanse, and perchance moisten..."

Green Heron showing third eyelid, the nictitating membrane.

Green Heron with eye fully open.

Example of nictitating membrane protecting female red-winged blackbird's eye from debris.

Tim Birkhead goes on to further describe how the nictitating membrane not only cleans the eye, but helps protect it: “Each time a pigeon puts its head down to peck at something on the ground, the nictitating membrane moves across the eye to protect it from spiky leaves and grasses. In raptors the membrane covers the eye immediately before the bird slams into its prey, and in exactly the same way the membrane covers the eye just before a plunging gannet hits the water.

Female Wood Duck with nictitating membrane closed over eye.

Female Wood Duck with eye full open.

Eastern Phoebe with eye open.

Eastern Phoebe with closed nictitating membrane over eye.

In analyzing my images of birds I’ve seen how the nictitating membrane will cover a woodpeckers eyes just before it begins pecking at a tree or stem. I’ve seen instances of the membrane closing just before a bird ruffles its feathers, shaking itself in the process of preening. And in most cases my camera’s shutter just happened to close at exactly the right time to catch the membrane closing or opening while the bird was standing still.

This post contains many examples of these third eyelids in a host of different birds. Most of these images have been heavily cropped to try to show the details around the birds eyes. I hope you find this topic as fascinating as I do. If you’ve never seen the nictitating membrane then keep your eye peeled for it next time you watch a bird up close through a camera or binoculars. Maybe you’ll catch it moving. Perhaps the bird’s eye will appear cloudy for just a moment. That’s the membrane closing and opening. The word nictitating comes from the Latin nictare, which means to blink.

Male red-winged blackbird with eye open.

Male red-winged blackbird with nictitating membrane closed.

Nictitating membrane beginning to close on male red-winged blackbird.

Nictitating membrane almost closed on male red-winged blackbird.

Another interesting tidbit from Bird Sense relates to us humans. Go look in a mirror some time. Look at the corner of your eye nearest your nose. There’s a little pink nub in the corner. That is the remnant of our own nictitating membrane.

Green Heron with eye wide open.

Cloudy eye of Green Heron caused by nictitating membrane (third eyelid).

Closeup of open eye on Green Heron.

Closeup of nictitating membrane on Green Heron.

Great Blue Heron with eye open.

Great Blue Heron with eye clouded over by nictitating membrane.

Great Blue Heron with eye (and beak) open.

Great Blue Heron with nictitating membrane partially closed over eye.


If you’re interested in learning more about birds, and what it might be like to be a bird, check out Tim Birkhead’s Bird Sense: What It’s Like to Be a Bird. The book is broken into 7 chapters, each describing a different aspect of how a bird experiences the world. The chapters are:

  1. Seeing

  2. Hearing

  3. Touch

  4. Taste

  5. Smell

  6. Magnetic Sense

  7. Emotions

I found this an absolutely fascinating read. Very educational.

Birders: The Central Park Effect - Review by Todd Henson

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Birders: The Central Park Effect is a beautiful documentary from 2012 by Jeffrey Kimball. It follows a group of people through the seasons as they go out birding in Manhattan's Central Park. The film is split into sections by season, beginning with spring, moving on to summer, autumn, winter, and back again to spring. The people birding are as varied as the birds and their numbers throughout the year also vary as do those of the birds. Some people only bird during the spring migration, when the song birds are moving north. Others bird the entire year, enjoying the variety of different species inhabiting the park during different seasons.

There are a number of birds who inhabit the park the entire year, making it their home during every season. These are the common birds, such as northern cardinals. When asked if he ever gets tired of looking at a cardinal, Lloyd Spitalnik replied: “If you get tired of looking at the common birds you might as well just pack it in. I mean, these birds are gorgeous.”

The birds who don’t stay in Central Park year round are called migrants. They migrate north in the spring, moving from tropical locales to the Canadian provinces where they can find an abundant food supply. They go there to breed and raise young. Dr. John Fitzpatrick, the Director of the Cornell Lab of Ornithology describes how millions of migrants move north during the night. At dawn thousands of them will stop over in Central Park, a perfect wooded location with plenty of food, allowing them to eat and rest during the day.

Central Park is not just a perfect location to stop, in many ways it’s one of the few available to them given the sprawling cities. The birds need a location with trees and greenery. They fly over the cities and notice Central Park, so they land and spend the day. Scientists call this the Central Park Effect.

Interestingly, Central Park is an entirely artificially created park. It is made to look natural, with small wooded areas and streams flowing through the park. But the streams can be turned on and off as needed. The park was created not just as a refuge for birds and other wildlife, but also as a location for people to congregate, to enjoy the benefits of these types of parks. There is a balance between nature and people.

During the summer the number of species seen in Central Park drops as the migrants have moved further north leaving the species that live in the park year round. As the number of bird species drop so, too, does the number of birders. But there are those who come to Central Park all year. There is still plenty to see, plenty of birds to watch and study.

It’s a joy to watch the light go on in somebody’s eyes when they see a bird and know what they’re looking at. And they kinda get it.
— Starr Saphir, who led bird walks in Central Park until her death from cancer in 2013

But when autumn arrives so, too, do migrants, this time heading south to their wintering grounds. And, as always, there are birders to watch and study them. During winter some species from colder northern climates travel to Central Park to spend the winter in the slightly warmer environment.

Winter is also a time when birders demonstrate themselves to be citizen scientists. Each December large numbers of birders get together for the annual Christmas Bird Count, where they attempt to count all the birds in a given area during a specific time period. They gather all their counts together and collate their findings. Over time they begin to see patterns emerge, how some species continue to do well, but many others do not. Over time they are seeing the overall number of birds dropping, a potentially troubling sign for the future.

I really enjoyed this film. I didn’t consider myself a birder, but I found myself smiling throughout the documentary, and I found the names of birds popping into my head as they appeared on screen.  I thought: I’m not a birder, I don’t keep lists. Then I realized I do actually keep lists right here on this website in my Field Notes sections, where I have lists of some of the species I’ve photographed along with the photos and notes about the species. I guess I am a birder after all.

This documentary will likely appeal to you if you are a birder, or just a bird lover. I enjoyed it not just for the talk and videos of birds in the park, but also the little snippets from the lives of several of the birders who frequent the park. Birders come from all walks of life, and vary as much as the birds do. But they all share the passion, the addiction, of getting out and watching for these remarkable little creatures.

See below for a preview of Birders: The Central Park Effect:

If you enjoy Birders: The Central Park Effect you may also enjoy the movie, A Birder’s Guide to Everything, staring Ben Kingsley and several young actors. It was a touching coming-of-age film about a young birder who thinks he’s made an amazing discovery and sets out with some good friends to find proof, while also dealing with a changing family situation as his father remarries.


Facing the Storm - The Story Behind the Image by Todd Henson

Facing the Storm, Rocky Mountain National Park (black and white)


Facing the Storm is an image I created while on vacation in Rocky Mountain National Park. The location is the end of the Tundra Communities Trail, which starts at Rock Cut just off Trail Ridge Road. The entire trail is paved and is a one-way in and back trail. The rock formations seen in the image are the end of the trail.

Tundra Communities Trail is a reasonably short trail, only 1 mile round trip to the rock formations and back. And the elevation change is only 200 feet. But I have to admit this trail completely wore me out. I spend most of my time on the east coast at sea level. This trail is at an elevation of over 12000 feet. That’s more than 2 and a quarter miles above sea level. I knew the air was thinner at those elevations, but not having been at them very often I’d forgotten just how much of a difference it makes. I was constantly stopping and catching my breath on the half mile hike up the tundra. This was a reminder I could use a little more exercise in my routine.

It was a beautiful trail surrounded by tundra, with flowers of various kinds blooming here and there. I could have spent far more time here than I did, but I only had one day, so I had to keep moving. I was fortunate the sky was full of interesting cloud formations, and storms could be seen in the distance. Rain was expected in this area, but it held off for the time I was there.

When I had almost reached the end of the trail, I stopped to take in the fantastic view and create a few photographs. I was most drawn to the sky and the storms in the distance. I loved the look of those storms against the rock formations. There were several people on top of the rock formations, and I was ok with that. Sometimes having a person in an image can help create a sense of scale.

Facing the Storm, unprocessed raw color photo, straight out of camera

The unprocessed raw color image gives a good indication of how the scene looked to my eyes. Unprocessed raw images straight out of the camera are often a little flat and this image shows that. It hasn’t yet had the processing applied to it that cameras automatically apply to JPEG images. That’s why we import raw images into software, to allow us to control how the image is processed instead of allowing the camera to do it for us.

I knew I would try converting many of the images I made to black and white, so I was most focused on the light, the texture of the rocks, and the tonal values of the scene and how they would translate to different values of grey. I smiled when the person with the white shirt climbed to the top of the rocks. I knew the white shirt would stand out nicely in a black and white conversion, and I loved how he was facing the direction of the storms. I imagined this lone individual, standing alone on the rocks, facing the storm and contemplating his life. Of course, there were other people on the rocks, but their clothing was darker and wouldn’t stand out quite as much. I’d have to wait and see how the photo looked after converting it to black and white.

After creating a few images I continued my hike to the rock formations, climbed to the top to see the view from there, and then slowly wandered back down to the car. The focus of this story is on this specific scene, but the location has much more to offer. As I mentioned earlier, the tundra can be covered in little flowers depending on the time of year. And I was fortunate on the hike back down to watch and photograph a group of elk walking along the ridge line very near by, close enough to get good images with my 70-200mm lens. Back at the trailhead, just across the road, is a sharp rocky drop off that is home to American pika and yellow-bellied marmots.

This is a location and a hike I highly recommend to anyone visiting Rocky Mountain National Park. The entire park is just stunningly beautiful. It’s difficult to find words to convey just how remarkable this park is. And I was only there for one day. I could have spent weeks wandering through the park. Go visit if you have the opportunity.


When I finally returned home it was time to open and process the raw images. I was looking for something bold, something that really showed off the texture of the rocks and the foreboding storm in the distance. I had captured the person with the white shirt facing towards the storm, so Facing the Storm seemed an obvious title for the image. I liked having the person standing atop the rocks, giving a little scale, with the winding curve of the trail leading right to the formation he’s standing on.

I usually do all my processing in Lightroom (or Aperture back in the day), but occasionally I will use a plugin package. For this particular image I used Silver Efex Pro from the Google Nik Collection. The collection contains a large number of plugins for a variety of situations, and Google has made the entire collection free, so check it out if you use Lightroom, Photoshop, or Aperture (though Apple has discontinued Aperture). Silver Efex Pro, used for black and white conversions, is my favorite tool from this collection. It contains a number of filters that affect the image in various ways. You can apply multiple filters, and each filter is fully adjustable, giving you endless control over how it affects the image.

Facing the Storm, initial black and white conversion using Silver Efex Pro

I was very pleased with my initial black and white conversion. I was able to capture the texture I’d wanted, and I brought out the drama in the sky. The person on the rock was easy to see with his white shirt (though it is much easier to see him on a larger screen). There were 3 other people on another portion of the rock, but they didn’t stand out quite as much and were secondary to the individual standing alone.

After Silver Efex Pro I took the image back into Lightroom to perform some final processing. I thought the dark cloudless region of sky at the top of the frame was distracting, so I decided to crop the image into a panorama format. After this I dodged and burned (lightened and darkened) portions of the image to bring out more texture in the landscape and to help direct the eye up the trail towards the rock formations. This is something that was often done in the darkroom with film, with one of the masters being Ansel Adams. I’ve been heavily influenced by his work.

One of the final steps was the removal of distracting elements. This has become much easier in the digital darkroom than it would have been in the film darkroom. And there is sometimes controversy surrounding this sort of digital manipulation. If I had created this image as a photojournalist, or to appear in a guidebook, I would have skipped this step. But because my focus here is creating an artistic image I have no problem removing distractions, though I am still very hesitant to add anything to an image. In this case I removed the sign post towards the bottom of the trail.

Facing the Storm, after further processing, dodging and burning, and removing distractions

While writing this post I began to look more closely at the image, and wondered if I might be able to make the message stronger. The title is Facing the Storm, and for me it’s about that single individual in the white shirt standing alone and facing the storm. So I thought removing the other 3 people on the rocks might bring this more into focus, might add that element of being alone in this wide open landscape facing the oncoming storm. And this resulted in the following image. I feel this image best captures my vision of the scene.

Facing the Storm, final version

Below is a slide show of each step. Click on the image to step through each version.

Let me know your thoughts. Would you have processed it differently? I ask myself this question all the time and will occasionally return to an image and refine or reprocess it. Do you ever reprocess your own images?