Bird carrying capacity and why druids are scary

[Belac93]

So. Long post incoming.

I was looking through my players handbook, and I noticed something: Owl Strength scores. 3. I flipped through, and checked some other animals. Falcon: 5. Frog: 1. Bat: 2. Seems reasonable, right?

Wrong.

I then took a look at the carrying capacity section:

Your carrying capacity is your Strength score multiplied by 15.

Not only that, but we get this little gem:

You can push, drag, or lift a weight in pounds up to twice your carrying capacity.

All of this, of course, is halved for tiny creatures.

HOWEVER, this still means that an Owl can lift something weighing up to 45 pounds. And they can still move at top speed while carrying up to 23 pounds!

With a falcon, these numbers go up to a whopping 75 pounds and 37 pounds.

Now: the average 4-year-old weighs between 34 and 36 pounds...

The average 10-year-old weighs between 70 and 72 pounds...

I think you can see where I'm going with this.

Imagine a world where things like owls and falcons regularly prey on humans children, or even halflings. Even if the bird is heavily encumbered, meaning they their speed will drop to 5 feet/round, that means they only need to move for 2 rounds to get to a height where 2 out of 3 adult humans will die if they fall. Children, in-game, are noted as usually being non-combatants with 1 health. This means that any fall from a height of 10 feet or more is instantly fatal for them.

These birds may only have 1 health, but that isn't a problem when children have no attacks whatsoever.

Imagine a world where birds shoot down from the sky, plucking lone children from the ground with ease. I envision transportation being a constant struggle to keep children in their caravans, safe from above.

An angry druid, convincing his bird friends to end humankind by making sure no child lives to adulthood ever again.

And that's not even bringing the others into the mix.

What if Ravens worked in packs, imitating a parent's calls to lure children away from their parents?

Bats swooping in silently, using their blindsight to hunt down prey while they slept.

Eagles have 6 strength. Carry weight of 90 pounds, lifting 180.

Vultures are medium size, with 7 strength and 5 health. That means carrying 105 pounds, or lifting up to 210. Now, not even the adults are safe.

Even a spider is strong enough to drag a 60 pound body off into the night, 5 feet at a time...

This isn't even mentioning giant animals.

And you know what?

Druids command them all. This is why they are feared. They may be tree-hugging hippies, but with a couple spells and a few words in the right ear, they could end humankind by eradicating their children.

That's why they are respected alongside wizards and sorcerers. Because what horrors would befall those who disobeyed them?

[Koo Rehtorb]

This is why "rules as a physic engine" doesn't work.

[Talyn]

Yeah, they probably should have put a "divide by 10 for flying creatures" or something. Riding fliers (or getting grabbed by flying creatures and dropped off of cliffs!) is a fantasy staple, it's not like you couldn't possibly expect it to come up.

If we divided by ten, you'd get, for a Small sized owl, a carrying capacity of 4.5 pounds, or a small cat. That looks about right.

Let's see if it works in the other direction - a Giant Eagle has a strength score of 16 (base carrying capacity 240) and is Large (x2) and flying (/10). So it could carry up to 48 pounds - a naked Halfling, but not a dwarf or a human. Hmm, Tolkien wouldn't approve. Maybe in Tolkien his Giant Eagles are actually size Huge?

According to a brief internet search, it looks like the Professor never specifically said how big they were, but the movies at least gave them a ~70 foot wingspan. That's definitely Huge, if not Gargantuan. Ok, so if they are size Huge, then they could hold a 96 pound weight. Still not enough.

Maybe divide by 8 instead of 10? That would let an owl pick up a 6 pound critter, which seems plausible, and would let a Huge eagle carry 120 pounds. Still not enough.

Divide by 5? That lets an owl carry 9 pounds, which is beginning to strain credibility, but is not so outrageous that I need to call fowl.* It lets our Huge giant eagle carry 192 pounds, or a good-sized human plus some gear. That seems to work.


TL:DR - after doing some math, a "Divide max carrying capacity for flying creatures by 5" rule seems to satisfy verisimilitude without being too difficult to implement.



* No apologies for the pun.

[Grod_The_Giant]

Does 5e have special rules for encumbrance while flying? I think 3.5 did.

Druids command them all. This is why they are feared. They may be tree-hugging hippies, but with a couple spells and a few words in the right ear, they could end humankind by eradicating their children.

That's why they are respected alongside wizards and sorcerers. Because what horrors would befall those who disobeyed them?

I vaguely remember seeing a 5e spell combo to deliver dozens of snakes to an unsuspecting victim...

[Flemkopf]

Druids command them all. This is why they are feared. They may be tree-hugging hippies, but with a couple spells and a few words in the right ear, they could end humankind by eradicating their children.

That's why they are respected alongside wizards and sorcerers. Because what horrors would befall those who disobeyed them?

I think you have just given me an idea for my next adventure with my group... {Evil laughter}

[ko_sct]

I'm not sure but I think that in 3.5 flying creatures couldn't fly if they carried more then a light load, so half the values you've given.

Of course that was only for creature flying under their own power, the fly spell allowed to fly while carrying up to your maximum load. It might have been 3.0 or in a supplement though.


Though we used that exact stratetgy to destroy a powerfull demon in one game I played in once. My druid wildshaped in the strongest bird he could, then my group casted enlarge person on him, then reduce object on a large rock (1/12 the original size). Flew high up till the spell was nearly over and dropped the rock. One pancake demon please.

[TheCountAlucard]

Also, I wouldn't let a bird just carry off a living humanoid without it first succeeding at a Grapple check.

(Incidentally, the Strix introduced in Hundred Devils Night Parade does exactly that!)

[tomandtish]

Divide by 5? That lets an owl carry 9 pounds, which is beginning to strain credibility, but is not so outrageous that I need to call fowl.* It lets our Huge giant eagle carry 192 pounds, or a good-sized human plus some gear. That seems to work.
* No apologies for the pun.

A large owl actually got our 16 pound dog off the ground once (he's very compact for his weight so looks more like a large rabbit in size) but dropped him after about three feet. So I'd buy that one could carry 9-10 pounds.

And it was weeks before our dog would go outside again, then he was running under bushes to take care of business.

[ATHATH]

I vaguely remember seeing a 5e spell combo to deliver dozens of snakes to an unsuspecting victim...

A quote from that thread is in my sig, if you need to find it again.

[Nupo]

A large owl actually got our 16 pound dog off the ground once (he's very compact for his weight so looks more like a large rabbit in size) but dropped him after about three feet. So I'd buy that one could carry 9-10 pounds.

I don't have much direct experience with owls, but large hawks struggle to get off the ground with 2 pounds. Hawks, falcons and eagles all max out carrying about half their own body weight. That means a large golden eagle can carry 6-7 pounds max. If it's flying and snatches something out of the air, or off the edge of a cliff, it can carry closer to it's full body weight, but it will be loosing altitude the whole time. The largest owl, the Eurasian eagle-owl (Bubo bubo) weighs up to 10 pounds, and the most common large owl in North America, the great-horned owl, is half that, topping out at 5 pounds for an exceptionally large individual. I'm told owls can carry a bit more than other raptors. For the sake of argument if we say they can carry a very generous twice as much, a large Eurasian eagle-owl would top out at carrying 10 pounds and a great-horned owl 5 pounds. While I'm not calling you a lier, I do wonder if maybe your story was exaggerated a bit.

[Grod_The_Giant]

A quote from that thread is in my sig, if you need to find it again.

Aha! Thanks!

[coolAlias]

I expected a discussion about airspeed velocity... but I suppose the question of laden vs. unladen birds is just as important as base speed.

Which edition are we dealing with, here? I'd guess 5e from the encumbrance rules mentioned, in which case yeah, it's not a great simulation of reality even for medium sized humanoids, and it breaks rather dramatically when you diverge from that.

I don't remember which edition it was, but there was at least one in which an adult dragon couldn't even lift itself.

[JBPuffin]

While I'm not calling you a lier, I do wonder if maybe your story was exaggerated a bit.

Give it a Google - Penny Arcade at the least has a podcast where their artist mentions an epidemic of birds stealing dogs in his area.

[Twizzly513]

*Tear comes to eye*
This is beautiful

Now let's all have a nice slow clap for RAW

[Nupo]

Give it a Google - Penny Arcade at the least has a podcast where their artist mentions an epidemic of birds stealing dogs in his area.

I'm not saying owls don't kill small dogs, they can, but carrying off a 16 pound dog, even just three feet, not likely. I have seen large hawks and falcons try to carry something weighing less than three pounds (a cottontail rabbit for example) and not even come close to getting it done. I'm not talking about internet videos that are easily faked. I am talking about seeing it in person with trained hawks and falcons numerous times.

[tomandtish]

I don't have much direct experience with owls, but large hawks struggle to get off the ground with 2 pounds. Hawks, falcons and eagles all max out carrying about half their own body weight. That means a large golden eagle can carry 6-7 pounds max. If it's flying and snatches something out of the air, or off the edge of a cliff, it can carry closer to it's full body weight, but it will be loosing altitude the whole time. The largest owl, the Eurasian eagle-owl (Bubo bubo) weighs up to 10 pounds, and the most common large owl in North America, the great-horned owl, is half that, topping out at 5 pounds for an exceptionally large individual. I'm told owls can carry a bit more than other raptors. For the sake of argument if we say they can carry a very generous twice as much, a large Eurasian eagle-owl would top out at carrying 10 pounds and a great-horned owl 5 pounds. While I'm not calling you a lier, I do wonder if maybe your story was exaggerated a bit.

Give it a Google - Penny Arcade at the least has a podcast where their artist mentions an epidemic of birds stealing dogs in his area.

I'm not saying owls don't kill small dogs, they can, but carrying off a 16 pound dog, even just three feet, not likely. I have seen large hawks and falcons try to carry something weighing less than three pounds (a cottontail rabbit for example) and not even come close to getting it done. I'm not talking about internet videos that are easily faked. I am talking about seeing it in person with trained hawks and falcons numerous times.

I believe I did say that the owl only got him about three feet off the ground before dropping him, whether because of weight, noise, etc. And we know it was about three feet because he was dropped OUTSIDE the dog fence (part of our backyard has a small 32" fence that we use to keep the dogs in "their part" of the yard). I don't think it could have carried him any appreciable distance. But we did have a vet bill for some nice deep punctures, and yes, we actually saw this happen (and it sure as heck looked like a large owl to us).

Edit: Actually, doing some googling seems to indicates that Great Horned Owls can potentially carry as much as 1.4 times their own weight, and there have apparently been studies that found some were taking prey in the 15 pound range. Given that, I'm less surprised that one went for a dog that LOOKS like he weighs 10 pounds, and am instead grateful that he doesn't ACTUALLY weigh 10 pounds.

[Excession]

The Haast's Eagle has been estimated to weigh up to 16 kg (35 lb). Pretty sure if those things were still around playgrounds would need some hefty bird nets.

[Squared]

I think you are under-estimating just how much a bird can carry.

From a standing stop position an eagle can't carry too much more than it's own weight, with plenty of speed.

Eagles can and do drop mountain goats off of cliffs.

Just check out Youtube for Eagle vs Goat. Also, eagles killing wolves.

^2

[hamishspence]

Eagles can and do drop mountain goats off of cliffs.

That would be Bull Rushing them off cliffs.

Half its own weight seems to be close to the upper limit.

While eagles attack much heavier prey - they generally won't carry it. I would guess that anything significantly larger than half the eagles weight, needs to be dismembered, disembowelled, etc. first.

[Max_Killjoy]

D&D rules that break down into ludicrous hilarity once you apply them more widely than the specific case of humanoids with classes and levels?

Never...

[hamishspence]

if you're using 3rd ed, then are you using Biped carrying capacity, or Quadruped carrying capacity, for birds?

The dire eagle (and the Giant Eagle, a Magical Beast) both have carrying capacities as appropriate to quadrupeds rather than bipeds.

Giant Eagle: Str 18 Large: 300 lb Light Load
Dire Eagle: Str 20 Large: 399 lb Light Load


Which, extrapolated to smaller birds, gives them:

Raven: Str 1 Tiny: 2.25 lb Light Load
Owl: Str 4 Tiny: 9.75 lb Light Load
Hawk: Str 6 Tiny: 15 lb Light Load
Eagle: Str 10 Small: 33 lb Light Load


With only "biped lifting power"


Raven: Str 1 Tiny: 1.5 lb Light Load
Owl: Str 4 Tiny: 6.5 lb Light Load
Hawk: Str 6 Tiny: 10 lb Light Load
Eagle: Str 10 Small: 24.75 lb Light Load

[Nupo]

I believe I did say that the owl only got him about three feet off the ground before dropping him, whether because of weight, noise, etc. And we know it was about three feet because he was dropped OUTSIDE the dog fence (part of our backyard has a small 32" fence that we use to keep the dogs in "their part" of the yard). I don't think it could have carried him any appreciable distance. But we did have a vet bill for some nice deep punctures, and yes, we actually saw this happen (and it sure as heck looked like a large owl to us).

I never doubted that an owl attacked your dog, just doubted it could get it three feet in the air. Was it a snatch and grab, where the owl never stopped? If so, with momentum it could get a bit more weight in the air. Are you sure your dog weighs 16 lbs? Also, if you don't mind sharing, what continent are you located on?

Edit: Actually, doing some googling seems to indicates that Great Horned Owls can potentially carry as much as 1.4 times their own weight

links please? If this was an actual study it would indicate that owls can carry three times as much as hawks and falcons. That would be interesting to know.

and there have apparently been studies that found some were taking prey in the 15 pound range. Given that, I'm less surprised that one went for a dog that LOOKS like he weighs 10 pounds, and am instead grateful that he doesn't ACTUALLY weigh 10 pounds.

Birds of prey commonly attack prey that is heavier than themselves, but they don't carry it away. They consume it (as much as they can eat anyway) on the spot. One of my falcons that weighs 32 ounces has killed sage grouse that weigh 7 pounds. That same falcon struggles to get off the ground with a 16 ounce pigeon.

I think you are under-estimating just how much a bird can carry.

From a standing stop position an eagle can't carry too much more than it's own weight, with plenty of speed.

Eagles can and do drop mountain goats off of cliffs.

Just check out Youtube for Eagle vs Goat. Also, eagles killing wolves.

^2

That would be Bull Rushing them off cliffs.

Half its own weight seems to be close to the upper limit.

While eagles attack much heavier prey - they generally won't carry it. I would guess that anything significantly larger than half the eagles weight, needs to be dismembered, disembowelled, etc. first.

Yes calling it a Bull Rush would be a good description. If you watch those videos they are loosing altitude quickly. I have seen my falcons bind to quarry in the air that is much heavier then themselves, but they don't "fly" with it. They do control, and somewhat slow, the fall, but it's not flying. More "falling with style."

If I was going to home brew a rule about how much weight things can fly with it would be:
- They can carry up to 1/4 of their own weight without penalty.
- Up to 1/2 their own weight with reduced speed and maneuverability. Also climb rate will be greatly slowed.

If I wanted to get more detailed I might try to figure out a way to adjust it slightly for exceptionally strong, or weak individuals. It wouldn't change the amount greatly however. No matter how strong it is, it still only has so much surface area on it's wings, and no matter how hard it flaps them, it can only generate so much lift.

[hamishspence]

3e had feats for flying with Medium and Heavy Loads.

If those feats were built into the basic flying rules - that would allow for the "heavily laden, slow flyer" - and if the Light, Medium, and Heavy loads were much lower when the creature was in flight - that would fix the issue.

Result- a creature can move easily on the ground with a Walking Light Load, but in flight, it'll probably be a Medium or Heavy load, that slows it.

[Nupo]

if you're using 3rd ed, then are you using Biped carrying capacity, or Quadruped carrying capacity, for birds?

The dire eagle (and the Giant Eagle, a Magical Beast) both have carrying capacities as appropriate to quadrupeds rather than bipeds.

Giant Eagle: Str 18 Large: 300 lb Light Load
Dire Eagle: Str 20 Large: 399 lb Light Load


Which, extrapolated to smaller birds, gives them:

Raven: Str 1 Tiny: 2.25 lb Light Load
Owl: Str 4 Tiny: 9.75 lb Light Load
Hawk: Str 6 Tiny: 15 lb Light Load
Eagle: Str 10 Small: 33 lb Light Load


With only "biped lifting power"


Raven: Str 1 Tiny: 1.5 lb Light Load
Owl: Str 4 Tiny: 6.5 lb Light Load
Hawk: Str 6 Tiny: 10 lb Light Load
Eagle: Str 10 Small: 24.75 lb Light Load

3e had feats for flying with Medium and Heavy Loads.

If those feats were built into the basic flying rules - that would allow for the "heavily laden, slow flyer" - and if the Light, Medium, and Heavy loads were much lower when the creature was in flight - that would fix the issue.

Result- a creature can move easily on the ground with a Walking Light Load, but in flight, it'll probably be a Medium or Heavy load, that slows it.

If you used the biped carrying capacity, and divided it by 10 it would be pretty close. That would put a hawk's light load at one pound, and medium at two. Can't fly with heavy load unless they have a feat allowing it. That would still be a little high but a lot easier to swallow.

[tomandtish]

I never doubted that an owl attacked your dog, just doubted it could get it three feet in the air. Was it a snatch and grab, where the owl never stopped? If so, with momentum it could get a bit more weight in the air. Are you sure your dog weighs 16 lbs? Also, if you don't mind sharing, what continent are you located on?

links please? If this was an actual study it would indicate that owls can carry three times as much as hawks and falcons. That would be interesting to know.

In the USA (Texas to be precise). And I've now found links that are claiming up to 3x weight. And yes, our dog weighs 16 pounds. One of the issues we have had with him is weight management (he was 19 at one point). And National Geographic notes "several times heavier than themselves".

[Nupo]

In the USA (Texas to be precise).

Thanks, so it was most likely a great horned owl. Just wanted to make sure it wasn't a Eurasian eagle-owl because they are about twice as big as great horned owls.

And I've now found links that are claiming up to 3x weight. And yes, our dog weighs 16 pounds. One of the issues we have had with him is weight management (he was 19 at one point). And National Geographic notes "several times heavier than themselves".

Thank you for the links. Neither site gives any evidence to back up their extraordinary claims. It's on the internet, it must be true. I have a real hard time believing an owl can carry six times as much as a similar size hawk. I know a few guys that hunt with trained owls. I might have to give them a shout and see what they have actually experienced. I can say, I have seen hawks and falcons attempt to carry items many times, and have never seen one be able to get off the ground (take off) with much more than half it's own body weight. Yes, with a snatch and grab their momentum can allow them to get heavier weights off the ground briefly, which is likely what happened with your dog.

[tomandtish]

Thanks, so it was most likely a great horned owl. Just wanted to make sure it wasn't a Eurasian eagle-owl because they are about twice as big as great horned owls.

Thank you for the links. Neither site gives any evidence to back up their extraordinary claims. It's on the internet, it must be true. I have a real hard time believing an owl can carry six times as much as a similar size hawk. I know a few guys that hunt with trained owls. I might have to give them a shout and see what they have actually experienced. I can say, I have seen hawks and falcons attempt to carry items many times, and have never seen one be able to get off the ground (take off) with much more than half it's own body weight. Yes, with a snatch and grab their momentum can allow them to get heavier weights off the ground briefly, which is likely what happened with your dog.

National Geographic is a fairly well-respected nature magazine, so I'll usually trust it until given reason to assume otherwise. But if you want more, here's a summary of 22 North American studies with 100 more more prey items each. Of note....

Mammal prey biomass ranged from 2 g, (masked shrew [Sorex cinereus]) to 6300 g, (striped skunk [Mephitis mephiti..

6300 grams = 6.3 kilograms, or about 13.8 pounds.

So yeah, our dog was a bit more than a large owl could actually carry away, which is what I believe I've been saying all along.

[Nupo]

National Geographic is a fairly well-respected nature magazine, so I'll usually trust it until given reason to assume otherwise.

I don't blame you for trusting National Geographic more than some random guy on an internet forum.
I sent them an email asking if they have any documentation to back that up. It will be interesting to see if I get a reply.

But if you want more, here's a summary of 22 North American studies with 100 more more prey items each. Of note....

This just deals with prey items. It doesn't deal with being able to carry it. Birds of prey commonly catch things that are too big to carry. They simply eat it where it lands.

So yeah, our dog was a bit more than a large owl could actually carry away, which is what I believe I've been saying all along.

Yes, I got that. I was just doubting that it could even get it three feet off the ground. I'm not saying it's not possible, especially with a snatch and grab. Just saying a similar size hawk or falcon wouldn't be able to get it done.

I also sent an email to a friend of mine that hunts jack rabbits with a Eurasian eagle-owl. He lives in Texas by-the-way. I will see if he has any insight about the carrying capacity of owls. This thread has really gotten me curious.

[tomandtish]

Me too. I've shot an e-mail to the Owl Research Institute to see what they say.

[Belac93]

if you're using 3rd ed, then are you using Biped carrying capacity, or Quadruped carrying capacity, for birds?

I'm actually using 5th edition rules. They don't have differences between the amount of legs, just the size and strength scores.