Hypothetically, how much do you think a (fictional) dragon eats?

Without being too spoilery, if anyone watched episode 6 of season 6 of game of thrones, you'll know that a certain character rides off with a horse and returns with a dragon. Me and a friend were jokingly agreeing that she probably fed the horse to the dragon, but also started wondering about a dragon's metabolism.

Do you think they would be similar to monitor lizards and Burmese pythons? Only eating once a month-ish as adults, or would they need to eat on a daily basis? Thoughts? :D

Would also depend on the size of the dragon :P

A dragon as big as a school bus will probably eat horses and cows and such... while a dragon that does not get bigger then a small car would probably do with pigs :rolleyes:

And how much ... i would say 2/3 times a week ... unless you keep it in rack then 1/2 a week jup!

Depends on whether the writer is Anne McCaffrey, Christopher Paolini, or Cressida Cowell.

I don't watch or read Game of Thrones, so here are my thoughts about generic dragons in general:

1. If they breath fire, they must have an extremely high internal body temperature, which presumably has high metabolic demands to maintain, even assuming that their skin has exceptional insulating properties.

2. However, many dragons do appear to have extended brumation periods on top of their piles of gold. Their metabolic requirements are presumably much lower during these times, and they seem to thrive and even grow on just the occasional knight or hero.

3. I also have to assume that a dragon requires much more iron and other metals in its diet than most animals, due to its high internal temperature and probably also to reinforce its bones and muscles in order for such a large animal to be able to fly. That's why they need a pile of gold in order to attract knights: they need the nutritional content of the plate armor, chain mail, etc. Princesses appear to fill the same function.

4. Speaking of flight, for a large animal to get off the ground requires a LOT of energy. I think Smaug in Lord of the Rings is roughly in the same ballpark, size-wise, as a 747. But he appears to be about the upper limit, size-wise, for fictional dragons that fly. Wagner's Fafner is said to be giant (and was a giant before he was a dragon...) but he's still small enough for Siegfried to slay with a sword. So dragons do seem to reach an adult size somewhere between the size of a horse and the size of a 747.
A 747 uses something like 1500 gallons of fuel during takeoff alone, or about 50 trillion calories, or about 8500 elephants (apparently jet fuel is more energy dense than elephants). Dragons don't go anywhere near as fast or as high, and for the sake of argument we'll say they're also much lighter than a similarly sized aircraft. So if they're a hundred times as efficient as a 747, Smaug would still burn 85 elephants' worth of calories just to get airborn. All that swooping around presumably burns a good bit too. My guess is that a dragon of Smaug's size would pretty much have to be able to slow down its metabolism and use the hoard as bait for knights and heroes, because going on a rampage in order to catch large game would have such high caloric costs that the dragon like Smaug would have to eat like an entire herd of wildebeest in order to come out ahead by the time it got home.

But dragons more the size of horses or elephants or small whales would have much more manageable caloric requirements, although flight would still be pretty demanding.

So in conclusion, a dragon that is very active, able to breathe fire, able to take off from the ground and perform complex aerial maneuvers, etc, probably has very high caloric requirements on the order of consuming its own weight in energy-dense food (e.g, not salad) somewhere between every 12 hours and every week. If it isn't able to brumate "on demand" when its energy stores run low, it probably dies of starvation extremely quickly, like a hummingbird.

However, a dragon that mostly sleeps on top of a hoard of treasure until a meal happens by has much lower requirements and can survive on the occasional knight or hero. Sort of like a ball python with its nose poking out of its hide, waiting for Furry Sir Gallahad the Squeaker to happen by.

Edit: Wow, I am really overthinking this......

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Originally Posted by Coluber42

I don't watch or read Game of Thrones, so here are my thoughts about generic dragons in general:

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Edit: Wow, I am really overthinking this......

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:rockon: That was brilliant!

I read the Temeraire series by Naomi Novik and thought it was pretty interesting she went extensively into diet, size, breeds etc of dragons. In those they ate quite a bit if active and more when younger for growth, a meal of a few cows or horses seemed to be the norm though.

If you keep your dragon in a smaller cage it wont get big...

Last night I watched The Hobbit. Smaug had been asleep under the mountain for hundreds of years before Bilbo woke him up.

And I thought ball pythons went on feeding strikes!!! :O

I tend to assume that a dragon should be more akin to a bird than a reptile, personally. Scales and feathers are not all that different. Lighter bones, frequent diet of relatively small items... now, I don't assume that the 'fire breathing' would require a higher internal temperature. More likely an arrangement somewhat like the ability to spit venom. Possibly containing a substance that ignites on contact with oxygen, if fire is really necessary, but more likely a type of venom or highly acidic toxin. Disable your prey, and start the digestive process at the same time.

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Originally Posted by Caspian

I tend to assume that a dragon should be more akin to a bird than a reptile, personally. Scales and feathers are not all that different. Lighter bones, frequent diet of relatively small items... now, I don't assume that the 'fire breathing' would require a higher internal temperature. More likely an arrangement somewhat like the ability to spit venom. Possibly containing a substance that ignites on contact with oxygen, if fire is really necessary, but more likely a type of venom or highly acidic toxin. Disable your prey, and start the digestive process at the same time.

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Or fire breathing could be accomplished by ejecting two"venoms" that combust when they mix. The Vernon ducts could then be aimed such that the two streams would actually combine a safe distance in front of the dragon's mouth. That would not only remove the requirement for a high internal temperature, but also reduce the need for as much thermal shielding or internal organs capable of withstanding high temperatures. Maybe that's an adaptation of dragons from regions without enough knights in steel armor.

It would, however, mean that certain types of injuries to the mouth, teeth, fangs, etc, could conceivably make the dragon's head explode.

Terry Pratchett's swamp dragons can breathe fire because of the volatile stew in their stomachs, but are rather prone to digestive difficulties of an explosive nature.

I like to go with the Flight of Dragons theory of dragonflight. They have a set of very hard teeth that can grind up limestone. They grind this limestone up and swallow it into a crop or a second stomach of sorts. There it is broken down into Hydrogen. This serves 2 purposes. 1st is it makes the dragon super buoyant and getting off the ground and staying airborne requires much much less effort than previously thought. 2nd is that it means they can be cold blooded and still breathe fire. Exhaling hydrogen from the air bladder will make maintaining flight more difficult or impossible after a point but some sort of bio ignition system in the top of the mouth would ignite the hydrogen on its way out.

Therefore you could have a flying dragon larger than what would be normally possible without an air bladder, cold blooded to require a lot less food than a warm blooded animal and extended brumation periods would allow a low intake of food for an animal so large. Small herd of cattle for an animal the size of a small airliner like a 737 could easily sustain it for a year or more which would keep the food supply from being too depleted, even with multiple animals.

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Originally Posted by Coluber42

It would, however, mean that certain types of injuries to the mouth, teeth, fangs, etc, could conceivably make the dragon's head explode.
Terry Pratchett's swamp dragons can breathe fire because of the volatile stew in their stomachs, but are rather prone to digestive difficulties of an explosive nature.

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This nearly made choke, I really shouldn't read and eat lunch at the same time. I just kept picturing a knight fending off a dragon bite, the dragon loosing some teeth and being really angry then attempting to cook the tiny human and BAM! it's head explodes :rofl:

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Originally Posted by ScottyDsntKnow

I like to go with the Flight of Dragons theory of dragonflight. They have a set of very hard teeth that can grind up limestone. They grind this limestone up and swallow it into a crop or a second stomach of sorts. There it is broken down into Hydrogen. This serves 2 purposes. 1st is it makes the dragon super buoyant and getting off the ground and staying airborne requires much much less effort than previously thought. 2nd is that it means they can be cold blooded and still breathe fire. Exhaling hydrogen from the air bladder will make maintaining flight more difficult or impossible after a point but some sort of bio ignition system in the top of the mouth would ignite the hydrogen on its way out.

Therefore you could have a flying dragon larger than what would be normally possible without an air bladder, cold blooded to require a lot less food than a warm blooded animal and extended brumation periods would allow a low intake of food for an animal so large. Small herd of cattle for an animal the size of a small airliner like a 737 could easily sustain it for a year or more which would keep the food supply from being too depleted, even with multiple animals.

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I like that theory!

It does seem that many sources describe dragons as being extremely long-lived, so in addition to spending a lot of that time brumating they probably also have a very slow reproductive rate, which would be necessary in order to keep the population density low enough to not exhaust the food supply. Maybe they are like 17-year cicadas, and every 113 years (113 because it is a prime number, it is over a century, and it ends in 13) they all come out at once to breed.

And then every 113 years they go on rampages, which is just often enough to keep the knights interested in making periodic attempts, thus providing the occasional interim mineral-rich snack. Otherwise they might have to gut-load the cattle with iron filings.

Well logically speaking since some dinosaurs evolved into birds I would assume that dragons split off from this lineage, at least based off Occams razor (google it but short version is the simplest explanation is usually right). Therefore I would assume that the firebreathing and the large size (anything over the generally accepted max 25kg weight for flying birds) would make flight possible by using something like hydrogen (think Hindenberg airship). I would also use the bombardier beetle as to the mechanism as it can produce an explosive irritant at high temps as to how it would work.

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Originally Posted by ScottyDsntKnow

I like to go with the Flight of Dragons theory of dragonflight. They have a set of very hard teeth that can grind up limestone. They grind this limestone up and swallow it into a crop or a second stomach of sorts. There it is broken down into Hydrogen. This serves 2 purposes. ....

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Unfortunately, limestone is mostly calcium carbonate (CaCO3). Stomach acid is mostly hydrochloric acid (HCl). Mixing acid and CaCO3 produces carbon dioxide, water and calcium chloride. No hydrogen. Zinc metal and hydrochloric acid would react to produce hydrogen gas.

A Boeing 747 is 70 m long with an interior cabin width of just over 6 m and an empty weight of 162 tonnes. That seems a bit excessive to me. Scrooge McDuck's money bin might not hold quite enough treasure to cover a dragon that big. The white dragon of Pern was about the size of a horse. But he was a dwarf specimen. Seems to me that a more realistic range would be somewhere between the size of an elephant (Asian elephants--2 to 3 m from shoulder to toe and 2 to 5 tonnes in weight) and a good sized sauropod dinosaur such as the Apatosaurus (formerly Brontosaurus), which was 21-27 m long, 3-4.6 m tall at the hips, and 30-35 tonnes in weight. But I can't visualize a physical mechanism that would let a creature in that size range actually get off the ground.

Sauropod dinosaurs had a pretty good sized "brain" in the spinal cord at the hips. We might postulate that the hindquarters brain had a levitation function built into it. And the wings were for maneuvering. Dragons are fantasy creatures, so why not a fantasy flight mechanism? :)

this thread raises a very good question and has many posts w/ valid points that i pretty much agree with.

:gj:


also how often do u guys think that dragons like to cook their food w/ their dragon fire breathe? or is that just a hunting or defensive thing? i wonder if dragons like their food rare, med rare, med or well done...

Now this is the kind of discussion I joined the forum for! :D Loving all these theories so far