Why birds do not fall while sleeping

> The only permanent bipeds of the animal kingdom alongside humans

Kangaroos?

Kangaroos engage in quadrupedal (actually pentapedal—using their tail as well) locomotion at slow speeds.

Humans also engage in quadrupedal locomotion, often at any speed and sometimes up stairs too.

Also, I see both of my dogs standing on 2 legs every day, often walking short distances like that. According to wikipedia this only happens when they are trained to do it (?!) but we never trained them and they've been doing it since a few months old. Maybe I should update https://en.wikipedia.org/wiki/Bipedalism to indicate training may not be required for temporary bipedal behavior in some dogs.

So do humans, babies and the elderly especially.

What has 4 legs in the morning, 2 in the afternoon, and 3 in the evening?

The key here is how relaxed is the interpretation of "permanent".

Birds migrating are mostly zero legging it!

To answer the question: a yacht race?

Also the wallaby and there are some hopping rodents found around the world.

I mean fuck, if that counts then I’m quadrupedal every time I go up the stairs quickly in my house

And the ground pangolin, apparently

I like the answer, I'm just not sure it's correct - are there any yacht races that have that many legs?

(Aside from AI Yacht's, of course: https://www.youtube.com/watch?v=U79-kDQnbPE )

something something wings are air-legs

Indeed, their trademark hopping is actually only really when stressed/startled.

Many of the animal sanctuaries in zoos in Australia actually have little signs telling visitors not to be disappointed if they don't see the animals actually hopping: "Laying down and sunbathing, and the slow walk with their tail is a sign of relaxation and a lack of stress on the animal."

Baby crawling adults walking and old man with cane?

Okay but that's a pretty long day, isn't it? I'm not sure that's a proper 'riddle', per se.

Oh. I did see one hopping across a local park. I didnt realize it might be stressed. I assumed like a dog they like to run.

Like it or not it's been a definitive example of a classic riddle since before it appeared in Oedipus Rex, an Athenian tragedy by Sophocles that was first performed c. 429 BC.

~ https://en.wikipedia.org/wiki/Oedipus_Rex

( spoiler: he loved his mother )

> Maybe I should update https://en.wikipedia.org/wiki/Bipedalism to indicate training may not be required for temporary bipedal behavior in some dogs.

That is against wikipedia's rules and thus will get reverted. You have to have a secondary source, not a primary source, and you're currently a primary source.

https://en.wikipedia.org/wiki/Wikipedia:No_original_research

> So do humans, babies and the elderly especially.

Only the healthy adult form is taken into account generally, you wouldn't say that dragonflies are mainly swimming animals for example, even if they do spend most of their life underwater as larvae.

The point here is that kangaroos that are capable of bipedal motion will always choose quadrupedal motion at low speeds. While humans who can walk will always choose to walk when possible.

In practice, most trivia on the site follows the "no source at all" policy, including the claim the GP suggested they might revise.

Whether it gets reverted essentially depends on whether someone would bother before it gets lost in the depths of the change history and how the GP chooses to respond if someone did.

Adults crawl all the time

Adults never choose to crawl, unless in tight spaces or drunk off their rocker.

you've never been to a teetotal claustrophile bdsm party

Mahy do. The Caribbean 600, for example.

Now, nobody is completing that race in one day, but that’s a different issue.

https://caribbean600.rorc.org/

> What has 4 legs in the morning, 2 in the afternoon, and 3 in the evening?

A table. My table. To solve this stupid riddle, I remove 2 of its legs before afternoon and screw one of them back on before the evening.

Sphinx, I dare you to refute me.

Yes we do, e.g. there's a sweet spot when scaling an incline (especially if there's easy handholds, e.g. a grassy incline) where using all fours is much easier and natural than making the same trips on two legs, even though you'd be perfectly capable of doing that too (i.e. I'm not talking about proper wall climbing).

And in the case of humans possessed by Satan, they frequently will engage in quadrupedal locomotion at speed down stairs and across walls/ceilings, bent over backwards like a demonic crab.

Pretty sure the Sphinx was talking about my "third leg" in the evening. In the morning I crawl on all fours until I get my coffee.

You’re right, but if I can extrapolate from myself to most adults, that’s approximately never.

I think I’ve done that once in the last 10 years, and I spend a fair bit of time in the woods.

But that’s not a normative mode of movement. Among healthy adults, quadrupedal locomotion will represent a small portion of their movement and is far from a comfortable means of movement thanks to our short arms compared to other apes who engage in quadrupedal movement a significant fraction of the time.