While looking at the little screech owl, I took a series of photographs and made this gif to illustrate the of the automatic grasping action of the talons.

The structure of bird feet is set up so that the foot automatically grasps when the ankle joint is bent.  

This automatic grip allow birds to sleep while perching, and for raptors clench/grasp prey as the leg is folded on impact.

The mechanism of the foot is ingenious…. there’s no muscle in there at all. 

The foot is powered entirely by a pulley system of tendons. 

Two tendons that run along the back of the leg, Flexor Digitorum Longus and Flexor Hallucis Longus are responsible for the automatic grasp. The former pulls the forward facing toes, and the latter pulls on the hallux, or back toe. 

I drew a schematic diagram of these two tendons here:

It’s particularly interesting in raptors.

Raptors swoop down on prey with talons/legs outstretched. The impact with the prey folds the raptor’s legs against its body, causing the talons to clench automatically, tearing into the prey. The automatic grip is strong enough to kill, and is what allows many hawk species to catch and kill other birds in midair. 

The ingenuity and perfection of this mechanism is mind-blowing.

Isn’t he cute? He looks almost alive. 

Unfortunately, he’s not.

This little guy is an eastern screech owl. Following a heavy storm, he was found dead on a residential street, entangled in some fallen branches at the base of a utility pole. 

I’ve previously posted a picture of him before.  I’ve never had the opportunity to look at owls close up.

He’s recently dead, his eyes have not yet begun to cloud or dessicate. Owl eyeballs are not spherical, they’re bell shaped, and fixed in their sockets. 

Since the eyes are fixed, owls move the entire head instead and can turn it almost all the way around.

There’s another lesser known effect of eye immobility. Owls have excellent vision but have close range astigmatism. The area just in front of them is always blurry. 

But that’s okay, because that blind spot is covered by crines. Crines are specialized whisker-like feathers around the beak area that extend into the blurry zone. 

These whiskers are highly sensitive, and allow the owl to “feel” for it’s food items, since it cannot see them. 

The owl’s capacity for silent flight comes from the fimbriate border of it’s flight feathers. This comb-like edge breaks up turbulence over the wing to reduce sound. 

These nubbins on his talons are called spicules, and are modified scales. Theyre common in birds of prey, and help improve grip by increasing the surface area, the same way fingerprints function in humans. 

Owing to the circumstances in which he was found, we initially believed him to be another unfortunate motor vehicle victim, but soon realized that this was not the case. 

There’s two blackened spots at the tips of his talons. 

His underside is a charred mass of feathers, and he’s got a faint “burnt” smell. The skin on the inside of his leg is roasted to a golden brown. The word “rotisserie” comes to mind.

I guess that power line wasn’t a safe perch after all. 

Can’t pass up the opportunity to make some more drawings.

A while ago, I was asked create a series of fact cards for Zoo Kingdom, a facebook game made by Blue Fang Games, the makers of Zoo Tycoon. 

Each species introduced in the game, had a series of fact cards that aimed to introduce some aspects of their natural history, morphology and ecology. 

I made about 150 of these. Below are my personal favorites. 

Making sketches of an Eastern Screech-Owl …a sad power line fatality.

To use him to educate others, is the least we can do. 

He’s a magnificent little creature.

Making sketches of a shortnose gar. These guys have very interesting jaw structure. 

Taking apart the baby skunk.

In the interests of length, this entry is mostly about internal organs.

All images are linked to high res versions, click to view.

NOTE: This post contains graphic images of an animal being skinned and photos of internal organs. It is NSFW and R-18G. Click “Read more” if you wish to see it. 

Read More

This baby skunk was picked up yesterday.

His teeth are perfect and show no wear. 

Elongated front claws for digging. 

He’s very small

This poor little guy is just a baby. He’s only the size of a squirrel and probably less than two months old. Just like the fawn, he was probably crossing the street with mom when he was hit. He’s still on his first coat of soft baby fur.  

While winter seems to have the greatest number of roadkill as animals disperse. Spring and early summer are sadly a time that a lot of babies die. Depressingly, the speed limit for the road was only 15mph. 

Here are some old and new photos of skulls I cleaned. With the exception of the sugar glider, these are all local North American species. 

Skunk, Coyote, Bear, Deer. 

Coyote, Spotted Skunk, Black Bear

Black bear

Crow Skull

Marrow cavity of a groundhog pelvis. 

Cervical & thoracic vertebrae from a groundhog. Most burrowing animals have robust neck vertebrae that are tightly joined. 

A closeup of the sugar glider skull. Notice the missing coronoid process on the jaw and the broken zygomatic arch. 

This is a detail shot of the front paw of the sugar glider that I put together here. It’s still articulated by natural connective tissue. 

Today is my brother’s birthday. 

He is officially 20. 

Mimi is adopted. Twenty years ago, he was picked up from a box of free kittens outside Walmart. 

He was one of a litter of five. At the time, he was only three weeks old. We fed him with a dropper until he was weaned.

He’s been with us ever since.

We go many places together. 

We have many adventures. Here he is crossing a creek. 

We are shopping for frozen foods. 

Mimi has been through a lot. He’s a little survivor. 

Due to his age, he has some health problems… but we still enjoy every day together. From now on, Mimi is going on 21.

It’s often the case, that only in death can many animals be examined in detail; their intricacy of texture and form eludes the eye admidst the fleeting motion of life.

I had originally put this together with the previous post, but had trouble loading so many images. 

Click on the images for high res photos. 

The chin scales of a timber rattle snake. 

The head of the smooth fronted caiman. If you take a close look at scales along his jaws, you’ll notice that each one has a small dot at the center.These are mechanoreceptors. Each dot is a dome of skin that covers a nerve ending. They’re used to detect slight disturbances in water, allowing the animal seek prey in even murky water. All crocodilians have these. 

The underside of the caiman. Notice the pattern of scales surrounding the cloaca and on the limbs. 

The head of a diamondback rattlesnake.

This large coastal carpet python belong to my friend Aaron. He lived in the herpetology lab for years until he was killed in a lab wide epidemic of unknown origin that killed most of the snakes in the lab. We never learned the origin or even the specific nature of the disease, although we suspect that may have had something to do with the introduction of a wild snake into the lab.

He has a really interesting ventral pattern. The photo doesn’t do justice to the brilliance of his yellows and greens. 

Here’s a detail of the heat sensitive pits along his jaw. They’re actually perforations in the scale that begin as in dentions at either end. 

It’s often the case, that only in death can many animals be examined in detail; their intricacy of texture and form eludes the eye admidst the fleeting motion of life.

Click on the images for high res photos. 

This is parakeet.

The projections on the foot of this red tailed hawk are called “spicules.” They are specialized scales that increase the surface area and help improve the hawk’s grip, allowing it to take better hold of struggling prey. Spicules are particularly prominent in birds of prey that feed on fish, like osprey. 

The wing of a raven in black and iridescent blue. 

As an invasive species in the US, the European starling is much maligned. They are the target of many pest management efforts, and represent such an ecological disaster that it’s actually difficult to find information on starlings written in anything bordering on a neutral tone. 

I’ve always thought of them as unremarkable, until I had the opportunity to see this one up close. 

They’re really quite beautiful aren’t they? Perhaps the admiration that must have belied their misguided introduction is somewhat ……..understandable. 

This guy was found dead in winter and is in his non-breeding plumage. You see how in the above photo, the white tips of his feathers are chipping off? By spring, he would have lost all his white “stars”’ to enter his glossy black breeding plumage. 

I took this a few days ago, during a routine trip to the park. The doe appeared for less than a second. Mimi remained oblivious to the whole event. 

It’s an amazing shot.

Anonymous asked: Hello, I have just come across your blog today, and I have to say it is strikingly fascinating and beautiful; the detail, images, explanation and language you use, both technical and wildly poetic, somehow combine to make this an extremely valuable piece of writing, for being personal and still informative. For a while I have been searching for a blog such as yours, which doesn't simply, messily showcase the inner workings of the anatomy- often stupidly, or even mockingly - yet you have the ability to present information succinctly and sensitively. Thank you for your lovely blog.

Thanks for reading my blog! I taught anatomy for a while and was always disappointed at the dull, confusing way that anatomy was often presented to students. I often tried to make supplemental materials to help or tell stories about the context and cultural history of various systems. 

If we strive to bring to light, the things that remain untold, the affliction of disinterested would be a rare phenomenon indeed. 

Thank you for taking the time to peruse my work. 

Anonymous asked: How did you get started in morphology?

I’ve always been really interested in art and science. My interest in biology wasn’t well defined until I took an animal anatomy class. The opportunity to study the bone structure and muscular anatomy not only help me draw better, but through anatomical study I came to understand the role of form and function in both the behavior of the organism, its ecology and evolutionary origins. 

Etched in each bone and woven into the fibers of each muscle is the life and death of the individual. Yet within the architecture on which the body is built, lies the story of its origins and its journey to the present day. The systems by which we have come to name, define and conceptrualize these complexities has a lot of cultural context, in terms of the way we have come to view our bodies.  

Morphology and by extension Anatomy are some of the most fascinating stories ever told. 

There seems to be a fair number of people who read my blog, so I’ve decided try out some interactive. 

I’ve put together a couple questions below. Would you like to take a guess? 

Question 1: 

This is a tray of skulls from a small museum I worked for. 

What are the two skulls at the front of the tray?

(Hint: One of them should be very easy, as I’ve previously blogged about it.)

Question 2: 

This is a buffalo skull. It’s the same skull that I cleaned in this post. 

It’s 22 inches across at the horns, and twenty inches long. I put my keys in the picture for reference. 

Here is a picture of me holding this skull. 

My question to you is:

How heavy is this skull? (I will accept lbs and kg.)

These seem to be fairly straightforward questions, but there’s some interesting points to both answers. 

You may answer via the reply function, or you may submit your answer here.

I’ll post the answer in a few days. Take a guess?