A problem that fantasy writers have when faced with long-lived races, such as elves, is population control. A common method is low fertility and/or an extremely long maturity rate, but this would make it extremely difficult for the race to ever rebound if something went wrong.
So here are other ideas.
- Breeding is controlled by government.
- Large amounts of the species are periodically killed off, i.e. in battles, esp. for those located in war zones, or participating in a war.
- Violent race that fights (and thus dies) a lot.
- High death rate among infants.
- Social/pheromone stimulation controls fertility: in an area dense with pheromones or heavily populated, a female is unlikely to come into estrus. If she is removed from her own kind, she will come into her breeding cycle.
- There's nothing wrong with their fertility; they just have a low sex drive.
- They have perfectly normal fertility and sex drive, but they are advanced enough for widespread acceptance of birth control.
- They require very specific conditions to breed.
- They are robots/androids and incapable of breeding.
- After they reproduce, they die.
- There are far more males than females.
- The extreme majority of the species is homosexual.
- The government/population employs mass, artificial population control (in other words, mass executions) to keep numbers low.
- Original Writerium Article