Writing about a setting with a nation of intelligent dragons has got me thinking about the limits of greater draconic society. I found the discussion here very helpful, but I want to expand on it. Specifically, if a dragon the size described in that question needs two pony-sized animals per week (I'm gonna guess that's 3 sheep per pony) to feed itself, than what sort of population density would be likely for dragons?
I would like estimates for both dragons sustaining themselves primarily by hunting for prey, and dragons getting food from vassal livestock tithes. A dragon that hunts could be calculated fairly easy; just figure out how much land a flock of sheep needs and do the math (about 30 acres for 100 sheep from what I see from a search).
A herder owning sheep for instance (I don't know of any pastoralist societies that herd ponies), let's say one herder gives 10 percent of his flock to his dragon overlord every month (just as a starting point); how big does his flock need to be, and how much pasture land does he need to feed it? How many herdsmen and thus square miles would the dragon need to make up any difference? How big could the dragon's family and entourage be if all the dragons have the same appetite (or would they need to live mostly separate from their friends and relations)? And how many dragon families could you have if the dragon race rules over, say, an area of approx. 250,000 square miles of land suitable for grazing?
I realize I'm asking a lot of questions all at once but I have no real clue where to start and I literally could change any of these variables as needed to get a workable answer. I hope to encourage a lot of math and statistics discussion.