Thursday, February 5, 2015

Walk this Way

I may be a geek, but I do like to shake my groove thing on the dance floor. To indulge my desire to boogie oogie oogie, I go to Zumba every Wednesday.
Shout out to my fabulous Zumba instructor, Sandy Castro!

Zumba is a great workout that moves your whole body, from your legs and feet to your arms and hands, and yes, there's a whole lotta booty shaking as well. We may not give much thought to how we move on a daily basis, but when you stop to watch other members of the animal kingdom, you'll see there's more than one way of getting around. 

Flatfooted: Plantigrade
When an animal walks with their foot bones flat on the ground, it is known as plantigrade. This is how humans walk and why I prefer my comfy hiking boots to heels--it's how we were made to walk, and after all, who is the Nature Geek to argue with nature? Plantigrade animals enjoy being the most efficient long distance walkers and an increased stability with their flat feet. Going back to my footwear example, who is easier to push over, a geek in boots or a model in stilettos?
That's gonna hurt tomorrow.

Squirrels are an example of a plantigrade animal. They have big, flat back feet which were just made for scaling trees and gripping tightly onto branches. But watch a squirrel closely and you'll discover something incredible about those feet. Watch the video clip below to find out!

The Ballerinas: Digitigrade
Next, we have the animals that are the true prima ballerinas. These animals always walk on their toes, known as digitigrade. Examples of digitigrade animals include cats,
and birds.
Many people at one time or another have pondered about birds' knees bending backwards and why they do so. The answer is that what is commonly regarded as the "knee" is actually the bird's ankle! The bones that come after the bend are really super long foot bones, and then of course, the toes. A bird's knees are close to the body and what we refer to as the "drumstick." So a bird's knees don't bend backwards at all, what you're seeing is an ankle joint that bends just like your own.

So what's the advantage of walking on your tiptoes all the time? First of all, digitigrade animals have the ability to walk much more softly than we flatfoots. Also, by having less contact with the ground, these animals increase their stride length and speed. The cheetah, the fastest land mammal, could never run as fast if its feet were plantigrade. But even though the cheetah may be the fastest, its speed is only short lived. If you want to be fast and efficient, you've gotta have even fancier feet. 

Which leads us to...

The Showoffs: Ungulates
You thought an animal walking on its toes all the time was an accomplishment? Try walking on just your toenails! That's what it means to be an ungulate, or unguligrade. The toenails on these animals have evolved to be thick and strong, and we call them hooves.

The fastest ungulate in the world is a hometown hero, the pronghorn antelope of North America.
"CMR Pronghorn USFWS" by USFWS Mountain-Prairie 

The story of the pronghorn's speed has always been one of my favorites. In the pronghorn's native range in the western United States, there are no predators that come close to rivaling its speed. So why are pronghorns so fast? Because during the Pleistocene the American cheetah roamed the plains. Today the American cheetah may be gone, but the pronghorn antelope and its speed live on.

Like with digitigrade animals, having a further reduction in toe bones in contact with the ground increases stride length and speed. So why wouldn't all digitigrade animals be unguligrade? The increase in speed comes with a trade off, decreased stability. Not only because of the tiny amount of surface area in contact with the ground, but also because of the lack of grip of hooves when compared to toes and feet. But try telling that to these dam goats.
 Click here for more about these unbounded ungulates.

Look Ma, No Hands!
I can't do a post on how animals move without giving some much due respect to snakes. After all, they don't have feet, toes, or even hooves, they manage to get along at some amazing speeds and even climb using only their belly. How do they do it?

Zumba is a great way for me to get up off my butt and get some exercise in the doldrums of winter as I wait for the warm days of spring to return. Whether you move your feet, toes, hooves, or do the worm (or snake) on your belly, do some moving this weekend and think about the different ways animals move while you're at it!


  1. That was great! I never knew why birds have backwards knees (ankles)!! Squirrels with swiveling ankles? Now that's too cool. Thanks also for the knowledge of a pronghorn adaptation as an homage to a long extinct predator. That venetian blinds analogy was perfect by the way. Thanks, Nature Geek!!

  2. You're welcome on all counts, Randy! Glad you enjoyed the post and learned something new! The swiveling ankles fact is always a favorite when I share it. It is truly amazing! Nature rocks.