Well, the dragons do have a long lifespan and their hoarding tendency seems to involve more storing food (gems) then eating them. I'd guess that young dragons tend to go through a "mine" phase to quickly grow larger and collect food to store. Then as they mature they get a bit less greedy (or at least get the urge to mate as well as greed) so that some form of reproduction can take place.Bright wrote:It wouldn't just make co-existing with other creatures hard; it would also make sharing space with other dragons difficult to say the least. From what we've seen, they're not very social creatures, with each adult dragon having their own territory. But what implications does that have for breeding? If the competition for resources is this steep, I don't see boy-dragons and girl-dragons getting along long enough to procreate. That would seem to indicate that the hoarding is either cyclical as you suggested, or eventually gets less compulsive as dragons age.
Interestingly, the dragon in "Dragonshy" left behind his treasure when he flew off. That always bugged me a bit. How did he even get it all to the mountain in the first place, or did he collect it all before going to sleep there?
In Dragonshy, the dragon seemed flattered by Rarities complements at least until she offered to "watch his hoard" at which point he drove her out. I doubt he was attracted to Rarity but it seems the idea of going out to show off his scales was a tempting thought. Dragon mating probably consists of dragons trying to watch over their hoards until one gets horny enough to leave and search for mates, then they find another dragon, prove they don't want the hoard (or offer gifts), and then try to procreate. Or depending on how messed up their life cycles and psychology are a dragon might wait until their potential mate goes into a 100 year sleep.
Actually, the dragons reaction in Owl's Well that Ends Well makes more sense given what we know now. We saw a tiny baby Spike chewing on a bit of the dragons horde, the dragon saw a little dragon that had the potential to get greedy and suddenly turn into a huge monster. So... it might not be much of a problem for dragons to mate with eachother but it does make caring for baby dragons into a bit of a risk. Few animals exist that can threaten a dragon but dragons can be a threat to eachother... even the young baby ones have the potential to suddenly grow huge enough to be a problem for the adults. I'm pretty sure an adult dragon can beat a greed-boosted baby dragon but it would be close enough that it wouldn't seem worth having one around. Imagine is five year old humans could suddenly grow as big as an adult once they learn to steal stuff.
So, maybe the ponies of Equestria have a deal going with the dragons where they take dragon eggs to hatch them and raise the baby in an environment where they keep the babies from getting greedy. The ponies sure don't want greedy dragons rampaging all over and the dragons don't want to worry about their kids turning into huge thugs and stealing everything the next time the parent takes a nap. Celestias rule has lasted for about 1000 years, seems long enough for the dragons to see things improved with this system over how things would be in the wild (or whatever the heck it was like under Discord).
As for the dragon in Dragonshy, its possible that he just flew out to find a new lair and was planning to come back later to move his gems to the new place. Also, it could be that this particular dragon had been raised by ponies and thus made his lair near Equestria out of familiarity and subsequently left once he learned that his snoring was causing problems for its inhabitants.