
Why Flamingos Are More Stable on One Leg Than Two - Sujan
https://www.theatlantic.com/science/archive/2017/05/flamingos-one-leg/527781/?single_page=true
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cmontella
Another great example of evolutionary wonders in birds is the albatross. They
have a tendon sheath that allows them to lock their wings open. This, combined
with their giant wingspan, their relative heft (albatrosses are porkers), and
some mysterious sensory mechanism and they are able to take advantage of wind
gradients to perform a maneuver called "dynamic soaring", wherein the bird
extracts energy from the wind. Scientists have measured the heartrate of
soaring albatrosses, and found it to be not much higher than their resting
heart rate. Albatrosses use this advantage to journey thousands of miles
across the pacific, without landing once.

Some more info:

[https://en.wikipedia.org/wiki/Albatross#Morphology_and_fligh...](https://en.wikipedia.org/wiki/Albatross#Morphology_and_flight)

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jessriedel
> wherein the bird extracts energy from the wind.

Just to be clear for others: the bird is gaining kinetic energy and/or
elevation (potential energy). It's not extracting energy from the wind and
converting it to chemical energy (fat/sugar).

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cmontella
Right, it still has to eat along the way :)

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pkulak
That was a lot of explanation about how the joints lock into place, but that's
not what's interesting to me. If I took a steel rod and put a stuffed animal
at the top of it, I wouldn't expect it to be inherently stable.

~~~
cmontella
Well, as the article lays out, it's a little more complicated than the leg
joints just locking into place. They couldn't figure out how the leg was
locking. It's only when they engaged the lock (by picking up the bird by the
shin) that they realized the entire body reconfigures to achieve the needed
stability:

> When a flamingo shifts onto one leg, two things happen. First, the leg
> inclines so that the foot moves from being directly under the hip to being
> directly under the center of the body. Second, the center of mass moves to
> just in front of the flamingo’s (hidden) knee, so its body weight naturally
> pulls the hip and knee forward. These two changes, combined with gravity’s
> pull and the shape of the leg bones, keeps all the joints in place.

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kazinator
The reason anything with two legs is more stable on one foot is that it has
the choice to immediately put the free foot anywhere in order to bring about
stability.

I have taught this to hikers who were struggling to get over some obstacles
such as boulders. Quit standing on both feet and teetering. Always keep one in
the air. When you step onto the next rock, lift the recovering foot, and keep
it up until you decide the next step.

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fjdlwlv
You said yourself that putting the second foot down doesn't increase
stability. It's a paradox.

~~~
robert_tweed
To answer this from the taijiquan perspective, the stability comes from being
properly balanced on one leg. The second leg is a spare for when something
happens unexpectedly like a gust of wind. By forcing people to keep one leg
off the ground, you're forcing them to balance on one leg and learn to be more
stable like that.

If you have no balance, it doesn't work. That's why tai chi is often
recommended for older people to improve their balance and reduce the risk of
falls.

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jlarocco
A much better write up of this, from one of the people who actually worked on
it, was posted the other day: [https://theconversation.com/neuromechanics-of-
flamingos-amaz...](https://theconversation.com/neuromechanics-of-flamingos-
amazing-feats-of-balance-78160)

And the HN discussion:
[https://news.ycombinator.com/item?id=14408786](https://news.ycombinator.com/item?id=14408786)

The Atlantic story linked here dumbs it down quite a bit.

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rubicon33
Heh... Interesting article.

I have a standing desk, and oddly enough, find it much easier to stand on 1
leg than 2. If it didn't take effort to keep my second leg up (in the yoga
pose) I could see standing like that for hours. My knee joint locks, and I
keep my balance easily with the support of the desk. For some reason, standing
on 2 feet is far less comfortable and requires more 'effort'.

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dmoy
Woah I never noticed this but yea, when I am at my standing desk I shift from
standing on one leg to standing on the other leg, shifting when my foot
complains.

(to address your yoga pose, just sort of half wrap the ankle around the back,
doesn't require much/any effort for the second leg if you let the toe drag all
the way down towards the ground)

~~~
rubicon33
Interesting, I'll give that a try. Thanks!

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Fezzik
This article reminded me of a hiking skill I never mastered - the Rocky
Mountain Rest Step (the name I learned it by, but I have heard others). It's
pretty simple - when hiking on steep slopes, especially with weight (a heavy
pack), you train yourself to lock your knee when stepping up to conserve
energy and "rest". I always found it rather uncomfortable, but I have climbed
with many strong mountaineers who swear by it.

[http://rockymountainhikingtrails.blogspot.com/2012/09/learni...](http://rockymountainhikingtrails.blogspot.com/2012/09/learning-
rest-step.html?m=1)

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thrw1001
> "We really wanted to do an experiment where we just walked over and gave
> them a little prod," says Chang. "But the zoo wouldn’t let us."

This is _hilarious_.

~~~
jaclaz
Though I doubt that the flamingo would let you come near it, but it could have
been a nice alternative to cow tipping:

[https://en.wikipedia.org/wiki/Cow_tipping](https://en.wikipedia.org/wiki/Cow_tipping)

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tomxor
Also dead fish can swim upstream... evolution has a way of just making things
work well mechanically.

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maxxxxx
I don't think 's true. What fish would that be?

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ploughjogger
It seems to be possible:
[http://www.people.fas.harvard.edu/~glauder/reprints_unzipped...](http://www.people.fas.harvard.edu/~glauder/reprints_unzipped/BealEtAl2006.pdf)

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justboxing
TL;DR (quoted from the article):

"When a flamingo shifts onto one leg, two things happen. First, the leg
inclines so that the foot moves from being directly under the hip to being
directly under the center of the body. Second, the center of mass moves to
just in front of the flamingo’s (hidden) knee, so its body weight naturally
pulls the hip and knee forward. These two changes, combined with gravity’s
pull and the shape of the leg bones, keeps all the joints in place."

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graphememes
flamingos are cool

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djsumdog
and smelly

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Avshalom
Nature smells so bad.

I grew up in Alaska and oh God seals and whales smell so bad.

