Did you know that ostriches are the only bird with 2 toes on each foot?
The flightless birds known for their long necks and quirky personalities have evolved to become the ultimate sprinters of the animal kingdom!
"Feet, don't fail me now!” is something you'll never hear an ostrich say. They’re one of the fastest animals on land, and can even run faster than Usain Bolt! :O
(An ostrich can run up to 70 km/h. Usain Bolt, considered one of the fastest humans in history, can run up to 44.72 km/h. Cool!)
The ostrich’s breakneck speed comes in spite of the fact that these birds have just two (admittedly gigantic) toes on each foot. In fact, they are the only birds in the whole world to have two toes on one foot - all other bird species have three toes, or more.
But why just two toes, and why is that important at all? Well, let's delve into the world of animal anatomy and find out
In the animal world, it seems like the secret to running fast like a pro is all in the toes!
It turns out the difference in toe numbers in animals is due to their evolutionary adaptations for running great distances. In all animals - from ostriches, to horses, to deer - fewer toes makes them much faster, and much more efficient runners.
That’s because it all comes down to efficiency and balance. The fewer toes there are, the less energy is needed to move those feet. And a single hoof instead of multiple toes allows for a more stable stride, helping them cover more ground in less time.
I had no idea that was a thing, and was so wowed by this fun fact when I learnt about it!
Let’s take a short break from ostriches to learn about another animal that loves running - horses!
The humble horse’s ancestor seems to have started off as three or four-toed creatures. But over millions and millions of year, the process of evolution helped them trim down to just ONE toe, making them the footloose and fancy-hooved creatures we know today.
Their middle toe evolved into a single large hoof, while the other toes became smaller and ultimately functionless. So, while only horses with single-toed hooves survive today, the remains of tiny vestigial toes can still actually be found on the bones above their hoofs.
Where Did Horses Come From? The majority of horse species evolved in North America. From there, they occasionally walked to other continents. About 20 million years ago, three-toed horses called anchitheres crossed to Asia and continued to Europe and Africa. About 11 million years ago, three-toed horses called hipparions spread from North America around the globe. About three million years ago, hoofed Equus, the ancestor of living horses, spread to several continents including South America.
Deer also joined in on the two-toed fun, and with those legs they can bound away from danger in a flash. Who needs to be a centipede when you can be a speedsdeer! (Like speedster, but deer. Geddit? No? Okay…)
Now, this is a bird blog, so let’s go back to the star of the show - the ostrich!
Standing tall at over 2.44 metres tall and weighing in at a range of 70 - 150 kilograms, the ostrich is the largest bird in the world.
But what we want to focus on today are their two-toed feet. As mentioned earlier, the fewer the toes, the better an animal is at running.
But these gigantic birds use their feet for other things too - like to scratch at the ground, and even to be used as a weapon in battle. The large toe is tipped with a 4-inch claw that helps the ostrich balance and steer while running - and also fight, I guess!
Two-toed… humans?
While doing research on today’s article, I learnt about a tribe of humans that have feet like an ostrich’s. They are the vaDoma people, from a tribe living in the Kanyemba region in the north of Zimbabwe, currently the only indigenous traditional hunter-gatherer tribe still living in Zimbabwe!
Sadly, however, due to massive amounts of inbreeding within the tribe, the children of the vaDoma people are famous for the inherited ‘ectrodactyly’ condition.
Ectrodactyly, also known as split hand or cleft hand, is a rare congenital disorder where one or more central digits of the hand or foot are missing or absent, leading to a claw-like appearance. It is caused by a failure in the formation of the hand during development and can affect the thumb, ring finger, and little finger. The incidence of cleft hand ranges from 1 in 90,000 births.
In people with ectrodactyly, their middle three toes are absent and the two outer ones are turned in.
However, among the vaDoma tribe, the ectrodactyly condition prevails because of the small genetic pool among the vaDoma - there is a tribal law that forbids members to marry outside the group, so this genetic mutation keeps being passed down from generation to generation.
But it’s not all bad! It is reported that those with the condition are not handicapped and are well integrated into the tribe. Some scientists think that this condition could possibly an aid in tree climbing, too! (I wonder if they run any faster than us five-toed humans?)
The high incidence rate of ectrodactyly among the vaDoma tribe has resulting in the tribe being known as the "two-toed" or "ostrich-footed" tribe.
Well, in conclusion, the world of animal anatomy is full of surprising and quirky adaptations. Whether you have one toe or five, every animal has its own unique set of adaptations that help them survive and thrive in their environment. So, the next time you see a horse, an ostrich, or a five-toed human, take a closer look at their feet and marvel at the wonders of evolution. Who knows, you might just learn something new!