Friday, December 12, 2008

Zygodactyl and other amazing owl facts - Owls Part II


Well, it is early in the morning...sometimes I feel like an owl (nocturnal)...I wish I could sleep, and since my neighbor friend who is also nocturnal at times has not called to do a Walmart run (it is open 24 hours you know --great way to beat the Christmas rush)...I just have my computer (as I have already mopped) to keep me company tonight. This may seem boring to most -- but here are some of the reasons why I have always thought owls were pretty awesome birds.

My intro with owls came when Chad and I found a dead snowy owl in the trees at the airport house. We took it home and kept it in our freezer (with the intent of someday stuffing it of course--otherwise it would have just been weird to keep a dead owl in our freezer)...We hauled that little owl carcass around with us wherever we moved to...It moved with us from the airport, to raymond, from raymond to the clear lake farm, from the clear lake farm to the chicken coops and then was finally deemed fit for a farewell when dad moved up to Calgary. We never did get it stuffed.
When I went to University I took up "owling" with a guy that Chad had met at Mount Royal. This very scientific past time involved going out late at night...driving to some remote (edge of the city or out of the city) forested location, taking a starry stroll into the forest...and playing playbacks of owl calls. This often would result in a heated conversation between the nearest owl in the area and our cd player...I have been dive-bombed by many a feisty Saw-whet. This hobby lasted all 4 years of University (with regular weekly, sometimes binightly owling outings)...and came to an abrupt end somewhere in my 4th year once I realized that my owling buddy/driver was adding a little something extra to his hot beverage to keep him warm at night. I suddenly became a little "too busy" if you know what I mean!!
The BBO was the next owl encounter...I was a bird bander and though I was only trained catching and banding songbirds, I did accompany other banders in their raptor banding expeditions...this involved climbing a tree in head-to-toe armor (protective parent birds), taking the little owlets out of the nest, putting them in a sac, lowering them to the ground, placing bands around their legs, placing them back in the sac, and getting them back up the tree and into the nest. Also, one of my daily chores as a bander at the BBO was radio tracking a Northern Saw-Whet pair...until they became some other raptors lunch. It was fun while it lasted.
IBS was the next owl adventure where I once again resumed my familiar past time of hauling around owl carcass. And this time not only did I have a beautiful stuffed snowy owl, but a great grey, a Northern Saw-whet, and a great horned owl all accompanied me to various places in the city while I shared just how cool these birds really are.
And in case you didn't know....Here are some of my favorite owl facts:

1. The most common foot arrangement is Anisodactyl and describes a foot having three toes in front and one behind.

Bald Eagle and American Goldfinch feet (Anisodactyl)Some birds (woodpeckers for example) are Zygodactyl...they have Two toes in front and two toes in the back (much like the letter "X" formation)

This is a woodpeckers foot...the zygodactyl formation allows them to cling to vertical trees...a great adaptation for trunk-climbing species.

Owls are cool because their feet are specially designed in a way that they can have an Anisodactyl foot formation or they can rotate their outside toe so it is in the back (now having two toes in front and toe toes in back)...a zygodactyl foot formation...which serves them well when catching prey..."When its feet touch the prey, its toes snap together like an avian mousetrap".

2. Parabolic Facial Discs...Owls have an excellent sense of hearing...their faces are shaped much like a parabolic dish (or satellite dish)...and that is what helps the sound to collect, amplified and then be directed to the ear openings. (you can experiment with this concept by trying to listen to a quiet radio...then cup your hands around your ears...the sound will be amplified).

Great Grey Owl.

3. Asymmetric ears...Their ear openings are very large in relationship to their skull, but they are asymmetrically placed on their head. In mammals (like us), our ear openings are symmetric. They're at the same height on each side of the head, they're at the same distance forward and backwards, and they're the same shape. But with an owl, it's different. One ear is higher than the other and more forward than the other, and they are both shaped differently. So what is happening, is that as sound comes to the ear, it comes to each ear ever so slightly different...This enables the owl to use triangulation to pinpoint the source of a sound, when the prey can not be seen. By tilting or moving their head until the sound is of equal volume in each ear, the owl can pinpoint the direction and distance of the sound. The result: a one-bird triangulation unit -- a handy adaptation when hunting prey you cannot in the dark of night. .
Barn Owl
4. Owl eyes --perhaps the most striking owly feature. Large and forward facing, they may account for one to five percent of the Owl's body weight, depending on species. The forward facing aspect of the eyes that give an Owl its "wise" appearance, also give it a wide range of "binocular" vision (seeing an object with both eyes at the same time). This means the owl can see objects in 3 dimensions (height, width, and depth), and can judge distances in a similar way to humans. The field of view for an owl is about 110 degrees, with about 70 degrees being binocular vision. An Owl's eyes are large in order to improve their efficiency, especially under low light conditions. In fact, the eyes are so well developed, that they are not eye balls as such, but elongated tubes. They are held in place by bony structures in the skull called Sclerotic rings. For this reason, an Owl cannot "roll" or move its eyes - that is, it can only look straight ahead!
5. 14 vertebrae... The Owl more than makes up for not being able to move it's eyes around by being able to turn its head around, and almost upside-down. It is able to achieve this by having a long and very flexible neck, which is not always apparent, as it is hidden by feathers and the Owl's posture. An owl's neck has 14 vertebrae, which is twice as many as humans (we have 7). This allows the owl to turn its head through a range of 270 degrees measured from a forward facing position. (imagine the owl is looking at you can turn it's head so it is looking over one shoulder...keep turning it's head so it is looking directly behind it...and keep turning it's head so it is looking over the opposite shoulder).
Northern Saw-whet Owl
7. Silent flight. If you were to find a Canadian goose feather (just one) and beat it up and down very fast you would see how noisy flying can be. An owls feather however is specially designed to break up sound and allow it to fly silently and stealthily.

The most unique adaptation of Owl feathers is the comb-like or fimbriate (fringe-like) leading edge of the primary wing feathers referred to as "flutings" or "fimbriae". With a normal bird in flight, air rushes over the surface of the wing, creating turbulence, which makes a gushing noise. With an Owl's wing, the comb-like feather edge breaks down the turbulence into little groups called micro-turbulences. This effectively muffles the sound of the air rushing over the wing surface and allows the Owl to fly silently. There is also an alternate theory that the flutings actually shift the sound energy created by the wingbeats to a higher frequency spectrum, where most creatures (including prey and humans) cannot hear.
Silent flight gives Owls the ability to capture prey by stealth, and also allows the Owl to use its hearing to locate potential prey. This adaptation is not present on some Owl species that hunt in the daytime.

8. Camouflage...In general, an Owl's cryptic colours and pattern allow it to blend in with its surroundings, hiding it from potential danger. This is especially important for the nocturnal owls, as they need to remain hidden when roosting in the daytime.When threatened, an owl will often take up a concealing posture, with closed eyes, raised ear tufts, and compacted feathers.The ear tufts are actually nothing to do with hearing, they are display feathers, used to indicate moods, such as fear, anger and excitement. They also help with camouflage. It is also interesting to note that although owls of the same species look alike, each individual owl within a species has slightly different markings. Can you find the owl???
The elusive pygmy owl...I had to travel all the way to the mid-coast of B.C to finally see one.


  1. Very cool Crystal. I now think owls are cool too. A little erie...but cool. I totally remember when you'd go out "Owling" with that guy. You sure have done some cool things.

  2. Very interesting owl facts Crystal. I'm glad to know there is a practical reason for their "satellite dish face".
    Also I was relieved to find out that when that owl turned its head all the way around and stared at me that one time so many years ago, it was not actually posessed by demons as I had imagined, but mearly had a very flexible neck. Thanks for setting me straight. Maybe now the nightmares will stop.

  3. CRYRSTAL YOU NEED TO SLEEP! very interesting, but you need to sleep lol

  4. srry i spelt your name wrong, i am typing 1 handed

  5. Lorin - I am glad that I could help put your mind at ease. Though you are not alone in your fears. Many religions/cultures (Native American) believe the owl to be the bearer of bad being visted by one at night (in a dream even) could mean imminent danger or mortal peril was to come...ahh, maybe I'm not actually helping anymore...sorry...owls are cool!

    Liam - I always spell my name wrong. "Crysalt" was a common mistake when I was me the nickname "salty" for many years.

  6. Crystal, your comments are as fun as your post just was. Not sure which I'm enjoying more at this point. (Salty that is!!!!)

    OK, is it true that a snowy owl is only snowy in the winter? I got thinking about that last night, and I believe that it's true, that they change color with the climate just like rabbits do, but if that's true, what is a snowy owl when it's not snowy outside? A barn owl? I hope I didn't just humiliate myself but seriously, who ever sees snowy owls in July?

  7. Crystal,
    I loved this post and am proud of how much you know about all these fascinating things.

    I think you humiliated yourself a little bit.

    - C