How large would a bird need to be to carry us aloft?

[Radrook]

I have always wondered how large a bird would need to be in order for an adult averaged sized human to saddle him up and fly him around. I mean we can ride ostriches but that isn’t flying.

The following bird was the largest flying bird ever. But was he big enough to carry let’s say, a 200 pound person aloft?


World's largest flying bird was like nothing alive today

The new species, Pelagornis sandersi, had an estimated wingspan of 20 to 24 feet when its feathers are included. This is up to more than twice as big as that of the royal albatross, the largest living flying bird, which has a wingspan of about 11.4 feet.

Here, an illustration of what may be the largest flying bird, an extinct beast with a wingspan of 20 to 24 feet (6.1 to 7.3 meters)....(Liz Bradford)

By Pelagornis.jpg: Ryan Sommaderivative work: Haplochromis (talk) - Pelagornis.jpg, CC BY-SA 2.0, File:Pelagornis miocaenus.jpg - Wikimedia Commons

 

[Ken Rank]

This should do the trick.

 

[~Anastasia~]

Eagles can carry off lambs.

It should be easy enough to work out. But it would be a big, big, BIG bird to offset the weight of a person, since weight and lift have to do with whether a bird can fly.

 

[Radrook]

This should do the trick.

Thanks for the fascinating video. Yes, I am aware that such birds have been depicted in films as well as included in sci fi fantasy short stories and novels. Do you think that Pelagornis Sandersi, the prehistoric bird I mentioned, was big enough for us to ride in that way?

 

[durangodawood]

Beyond a point, living beings cant just be "scaled up" in a linear fashion.

To oversimplify, look at a weight-bearing leg bone.

The load capacity of the bone increases roughly per the square of the linear increase in the animal's size. (cross sectional area of leg bone)

But the overall load increases per the cube of the linear increase in size. (total body mass)

This is why ants can have really skinny legs compared to body mass, while hippos have to have broad thick legs.

 

[Ken Rank]

Thanks for the fascinating video. Yes, I am aware that such birds have been depicted in films as well as included in sci fi fantasy short stories and novels. Do you think that Pelagornis Sandersi, the prehistoric bird I mentioned, was big enough for us to ride in that way?

Probably not. The estimated wing span of the Pelagornis Sandersi is 13', just under 3' longer than a Condor which cannot come close to carrying a 200 pound man.

 

[Radrook]

Eagles can carry off lambs.

It should be easy enough to work out. But it would be a big, big, BIG bird to offset the weight of a person, since weight and lift have to do with whether a bird can fly.

Do the birds shown in that Lord of Rings video meet that size requirement? How about Pelagornis Sandersi, the bird I mentioned in the oped? Does it meet that size criterion?

 

[Radrook]

Probably not. The estimated wing span of the Pelagornis Sandersi is 13', just under 3' longer than a Condor which cannot come close to carrying a 200 pound man.

According to the article at the link I poste, it had a wingspan of 20 to 24 feet (6.1 to 7.3 meters)
If indeed the above estimate is accurate, would it then be able? Wouldn't that body proportion be comparable to the creatures shown in the film Lord of Rings and in the film, Avatar?

 

[~Anastasia~]

Do the birds shown in that Lord of Rings video meet that size requirement? How about Pelagornis Sandersi, the bird I mentioned in the oped? Does it meet that size criterion?

Well, you also have to consider that some very LARGE birds don't hunt very large prey, comparatively. Some have more body mass or are a bit more ungainly, and so even being huge wouldn't add that much ability.

It's certainly not something I've thought about before. But eagles are built such that they are fairly capable to bear weight, based on their weight, wingspan, strength, and do on.

Just glancing at your drawing, my guess (and that's all it is) would be that they really couldn't carry all that much.

I'm also wondering if you HAD an eagle-like bird of sufficient size, perhaps the dynamics of flight would be changed based on the gross change of the animal's body size, so it might not be able to fly at all.

I'm no expert at all. If you mean it for a fantasy kind of question, I'd say a huge eagle-like bird might manage. If you mean it as an actual question, I'm not sure if physics would make it really impossible.

 

[essentialsaltes]

Durango has it right. The square cube law puts a harsh limit on things.

Perhaps the correct question is "how many birds would you need to carry us aloft?"

And the next most important question is, "Are they African swallows or European swallows?"

An African swallow can carry a one pound coconut. So if you constructed a light frame to distribute the weight evenly, and could train the swallows to work together, it wouldn't take much more than 200 African swallows.

 

[Radrook]

Beyond a point, living beings cant just be "scaled up" in a linear fashion.

To oversimplify, look at a weight-bearing leg bone.

The load capacity of the bone increases roughly per the square of the linear increase in the animal's size. (cross sectional area of leg bone)

But the overall load increases per the cube of the linear increase in size. (total body mass)

This is why ants can have really skinny legs compared to body mass, while hippos have to have broad thick legs.

So would the creature I mentioned be able or not be able to carry that load?

 

[Radrook]

Well, you also have to consider that some very LARGE birds don't hunt very large prey, comparatively. Some have more body mass or are a bit more ungainly, and so even being huge wouldn't add that much ability.

It's certainly not something I've thought about before. But eagles are built such that they are fairly capable to bear weight, based on their weight, wingspan, strength, and do on.

Just glancing at your drawing, my guess (and that's all it is) would be that they really couldn't carry all that much.

I'm also wondering if you HAD an eagle-like bird of sufficient size, perhaps the dynamics of flight would be changed based on the gross change of the animal's body size, so it might not be able to fly at all.

I'm no expert at all. If you mean it for a fantasy kind of question, I'd say a huge eagle-like bird might manage. If you mean it as an actual question, I'm not sure if physics would make it really impossible.

It is a actual question based on what I have observed in films depicting such creatures easily carrying humans aloft.

BTW
Thanks for the feedback to all that have responded

 

[essentialsaltes]

Note that the Pelagornis sandersi itself weighed less than 100 pounds at most, and was likely barely able to fly (if at all) "probably able to fly only by hopping off cliff edges".

 

[Radrook]

Note that the Pelagornis sandersi itself weighed less than 100 pounds at most, and was likely barely able to fly (if at all) "probably able to fly only by hopping off cliff edges".

Was wondering why they didn't include its actual weight. If indeed it was that light then of course it would be unable. The eagles depicted in Lord of Rings look far heavier than a mere 100 pounds as do the creatures in Avatar. It would be indeed wonderful if we could actually have a creature to fly us around in that way. Perhaps there actually was one among the pterodactyls or pteradons?

 

[~Anastasia~]

Note that the Pelagornis sandersi itself weighed less than 100 pounds at most, and was likely barely able to fly (if at all) "probably able to fly only by hopping off cliff edges".

Yep, add 200 pounds and it would drop like a stone off the cliff in that case.

 

[Radrook]

Yep, add 200 pounds and it would drop like a stone off the cliff in that case.

With my luck if I were all saddled up and hunched on its back it would continue all the way down straight into the rocks even if it were as big as a house.

 

[durangodawood]

So would the creature I mentioned be able or not be able to carry that load?

I say no. From the article it seems like it was maxed out just dealing with its own weight.

 

[Radrook]

I say no. From the article it seems like it was maxed out just dealing with its own weight.

Miserable sounding creature! IMHO!

 

[JacquelineDeane55]

Wow, what a beautiful bird! Don't you just love animals? I like animals.

 

[Radrook]

Wow, what a beautiful bird! Don't you just love animals? I like animals.

In the painting as it soars beautifully in that majestic way I agree-it is beautiful. I was referring to the way that he described it as hobbling on the ground barely able to get around and falling like a rock whenever it tried to get aloft by diving off a cliff.