This might be a really weird question, but why do Kangaroos jump instead of walk?
As a human jumping takes a lot more energy than jumping, so it must be something biological, but they are like the only animal family that does that (I’m sure there are more kangaroo-like animals I don’t know about)?
Edit – After seeing a few comments, this post isn’t about why the evolved to do so (even though it is an interesting question), I was asking what is the anatomical reasoning for it.
In: 418
Because their legs work like springs. The kangaroo uses less enery when it jumps because it stores the energy from landing and uses 8t for the next jump.
So now that we got that out of the way, how far can a “roo” travel without stopping or in a day? I must know, TYIA
Hopping is much more efficient than walking, they have anotomically evolved to gave two giant springs for legs that propel them forward with minimal use of energy. I did hear that they are the most efficient movers in the animal world when considering energy spent.
I’ve also heard humans move more efficiently while skipping rather than walking/running. I don’t remember where I heard that but I do like the idea of our ancient ancestors skipping about all day looking for a feed.
With the way they evolved, jumping is a more efficient method than walking.
They have long feet and incredibly strong leg muscles designed for jumping, using their feet as leverage they can jump very far very easily, and over long distances and time periods. They are built for jumping in the same way cheetahs are built for running: very good at that, awkward at doing anything else.
Plus, being able to move quickly is a survival trait in a country that regularly catches fire in a catastrophic manner. Jumping they way they do is faster than walking.
Also a fun fact, their digestive organs actually move in rhythm when they jump, so they get a benefit to their digestion when they jump from place to place.
Because it’s actually a very efficient way of travelling. Kangaroos have elastic tendons and ligaments that store energy when they land, and recycle it into the next leap. Tests show that they’re actually [among the most efficient users of energy for movement](https://www.upi.com/Archives/1986/01/08/Science-Today-Kangaroo-Energy-Efficiency-Just-Like-A-Pogo-Stick/5720505544400/).
Kangaroo are actually hopping on their toes. The lever is around their ankle, where some muscles from your knees to your toes are being stretched and pulled back (like that reflex test that the doctor does on your knee ).
Compare with when you run. It’s easier and less tiring to run on your toes than your whole feet. Because the reflex from the muscles use less energy than actively using the same muscles.
This is literally the crux of both morphology and physiology. I’m not making dunno you, but you could just as easily ask, “Why don’t peille swim by wiggling their body side to side? It works for fish and crocodiles?”
Jumping is SO much easier than walking or jogging, for a kangaroo. So much so that it is l one of the most energy-efficient forms of animal movement t ever to evolve, about tied with humans, who have INSANE levels of efficiency in a walk or slow run, and about double humans, much, much more efficient at high speeds.
To walk like us, though, a kangaroo’s waist is too stiff, it’s pelvis is all wrong both in the angle of the pelvis, the location of the hip sockets, and angle of the hips. It’s limb proportions between the femur, the tib/fib, and tarsal bones is way off, and it’s foot is too stiff (it would have to walk on the tips of it’s claws/nails. They can’t straighten their knee fully, and don’t have proper kneecaps. Just for starters.
To walk on two legs like a dinosaur would be easier, but still not right. Remember kangaroo ancestors probably DID stride with their back legs when they still used their front legs. In that case the absence of some key muscles that run from the base of the tail to legs are missing. Dinosaurs had something called a caudofemoralis muscle, but mammals don’t, so our “glutes” and lower back muscles that support our stride are above the leg, and not on our tails, and are not used the same way. That’s why 4-legged mammals walk, shuffle, trot, bound, etc.. on a dinosaur or a chicken the step and stride is exactly the same, just faster and faster.
So, take an animal like a rabbit, which is an exaggerated bounder and leaper. Even when “walking” a bunny doesn’t go left/right front, right/left back like a cat does. He takes little slow-motion hops, both fronts then both backs.. Speed that up and he’s taking long leaps. Why don’t rabbits bounce on his their hind legs, then? They SOMETIMES do, but the posture Is very upright, because they don’t have a balancing tail, for one, and their plump rumps are way in the back.
Wish they walked instead of jumping then they wouldn’t cause so much damage as they do when they jump in front of your car at 110kmh
It takes a heap of energy for you to keep jumping but it is extremely efficient with their biology.
https://www.orlandosentinel.com/news/os-xpm-1986-01-19-0190220124-story.html
>The red kangaroo of the Australian plains is probably the most efficient ground animal in the world. When hopping along at the speed of a world-class marathon runner, it uses half as much energy as a human.
>A marathoner’s speed is nothing for this 7-foot pogo stick. Its top speed is three times faster — about 40 miles an hour, with each hop extending as much as 18 feet.
Worth reading the whole thing if you have a few min.
Kangaroo legs are adapted so that energy from moving up and down can be transferred through the elasticity of their muscles (while using little energy themselves) into forward motion. This allows them to get to high speeds easily. You can see similar behaviours in some birds on the ground, not only in land mammals and monkeys. In conclusion, jumping is more efficient for kangaroos than walking like we do because their bone structure is different.
Also looked up kangaroo and kinda shocked by how there are multiple different [sub]species. There’s even a tree kangaroo.
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