Cheetahs' inner ear is one-of-a-kind, vital to high-speed hunting | Hacker News Reader

Cheetahs' inner ear is one-of-a-kind, vital to high-speed hunting

eurekalert.org

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Relevant, cheetahs running filmed with an high speed camera: Cheetahs on the Edge—Director’s Cut https://vimeo.com/53914149

I have watched this video dozens of times. It is like an hour of meditative breathing exercises condensed into 5 minutes.

Thanks for this clip, it's amazing how it keeps the head still. BTW, the kingfisher has similar ability, check this https://www.youtube.com/watch?v=NIs4tpV2FUQ

Optical image stabilization! I am interested to see that this seems to be the way various predators have solved the problem, I take it that unlike the direction our camera technology is going (which is to throw more software at the problem), it was most economical to use a lot of tiny neck muscle adjustments (no Moore's law for predator brains, to be fair, so it might have tied up a lot of neurons to do the same in software).

>> the cheetah, is a successful hunter not only because it is quick, but also because it can hold an incredibly still gaze while pursuing prey.

A bit off-topic but I have a theory on athletic ability when it comes to certain sports related to this post. Before I share my theory, consider this 1 minute clip narrated by an apex predator.

https://youtu.be/S9MtJ164XJI?t=1m24s

When I was young there was a lot of ethic tension in my neighborhood. Being a minority, I always felt like prey. I didn't even trust the police. I lost every street fight and broke a few bones along the way. And I was terrible at almost all ball sports because I could not get my eyes to smoothly track the motion of a basketball for example.

I suspect, but don't know for a fact, that they eyes of prey being chased by said cheetah are darting chaotically looking for any and all escape routes and to avoid additional predators.

In my 30's I spent time training in brutal martial art combat techniques. I trained in powerlifting and 10 years ago I weighed 200lbs. I grew muscles I didn't know existed. Now, I have lost nearly all of these gains because I no longer train, but I managed to achieve and maintain that predator instinct. When I play racquetball, I murder that ball. I can track it perfectly.

The downside is I have safely ridden a motorcycle most of my life. I find I have more "close calls" now that I lost my innate ability to feel like prey which no longer comes naturally.

Ride safe bud. Wear good gear and be disciplined about maintenance.

For lack of a better way to phrase it...what exactly is your point?

He's proposing a theroy about human behavior. His idea is that when people are used to feeling unsafe they tend towards prey animal survival strategies (eyes darting around, focusing on escape routes instead of goals) and that when people get used to being on top of things they tend to adopt predator animal behaviors (eyes on the ball, focusing on goals instead of possible escapes.)

The reason I wasn't sure this was what he was trying to say is that good motorcyclists tend to keep their eyes steady on the horizon, and yet also, they continuously identify possible escape routes.

Interesting article. Sounds like the cheetah has a sort of natural implementation of camera stabilization. Their head stays still despite the exaggerated motion of everything else during a high speed chase.

Don't humans have this too?

Yes. Pretty much all vertebrates have something like this. The claim here is that cheetah's have an unusually well developed vestibular system, and that this evolution was recent (developed after the 'concept' of a cheetah evolved).

The linked paper is free to read. The actual research itself is limited to the anatomical study of how cheetah's vestibular system are different from other cats. It builds on other papers that talk about the relative advanceness of the cheetah's head stabilization, and the estimated benefits of the stabilization.

Specifically from the article:

> They found that the inner ears of living cheetahs differ markedly from those of all other felids alive today, with a greater overall volume of the vestibular system and longer anterior and posterior semicircular canals.

> These traits were not present in Acinonyx pardinensis, the extinct species examined by the researchers, emphasizing the recent evolution of the highly specialized inner ear of modern cheetah.

In a rough sense, but maybe keeping your eyes fixed on something on a high-speed roller coaster that shakes a lot would be a better comparison of cheetah vs human stabilization.

I also wonder if there is some technology or lesson we can learn from this, more than just learning about our world and the animals in it. Either way it's fine, but it's always fun to wonder about the opportunity.

Humans have a tighter feedback to the muscles in the eyes and do most of the stabilization that way. Chickens don't have that sort of eye movement, and so they have to be more responsive with their head.

This is a characteristic you think humans have? https://www.youtube.com/watch?v=8gy55o76SZc

It's something you'll see a trained ballerina do when twirling, but I'm not about to say humans walk on their toes.

Ballet dancers are trained to do turns (fouette [0], pique [1] and pirouettes [2]) by "spotting" (i.e. picking an object in the near distance and spotting it until the next turn). I'm not sure the chicken video does this term justice, hence the links below.

[0] https://www.instagram.com/p/2ZOLkkHMKU/?taken-by=devon.teusc...]

[1] https://www.instagram.com/p/BeoYE2DlTXF/?taken-by=tilerpeck

[2] https://www.instagram.com/p/BT4WSbmDMKM/?taken-by=devon.teus...

We do have a "poor man's" version of it I guess. Coz our sense of balance does reside in the inner ear.

> The inner ear facilitates the cheetah's remarkable ability to maintain visual and postural stability while running and capturing prey at speeds of up to 65 miles per hour. Until now, no one has investigated the inner ear's role in this incredible hunting specialization.

This is crazy. How does the ear affect the ability to move? I guess Cheetahs and cats in general just have insanely acute hearing.

The inner ear (vestibular system) helps you maintain balance. The inner ear has a series of curved liquid filled canals that are also lined with sensitive hairs. As your head accelerates, the liquid sloshes around and the hairs pick up on the movement.

Being able to stablize your head during running lets you do a few thing:

* It probably makes it easier to continue tracking the prey. It probably makes it easier to see what the prey is doing (are they about to turn? are they looking somewhere? what's going on?)

* While running, if you can minimize any vertical movement, you can minimize energy consumption. Presumably even if your body/shoulders were displacing vertically while running, if you could maintain your head at a fixed vertical position with respect to the ground, you could save the energy put into moving the head against gravity. Obviously this advantage is heavily biomechanically and anatomically situational, and may not always be the case

The article goes into depth on this. It has nothing to do with hearing, but rather the balance system of the inner ear. Cheetas' inner ears are different from other cats, and they have more brainpower for processing the balance signals, so they are more sensitive and more responsive when it comes to feats of balance. This helps them hunt at very high speeds because they're able to keep their heads stabilized and fixed on their prey.

The very cool chicken based steady cam vid should give you an idea https://youtu.be/_dPlkFPowCc

https://youtu.be/UytSNlHw8J8

Kind of the same way your eyes help you stay balanced. Try and close your eyes and stand on one foot.

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