Alright, I'm trying to figure out if the Drow as written could survive. Because huge math equations make me cry a little I decided that the best way to do this is brute force with perl. So, after 6 hours writing a script I finally have something that doesn't suck, now it's onto finding actual numbers to base the estimates off of.
Where I'm at now:
Basing the Drow directly off of the Elf entry in the 3.5 SRD I have them living to age 300 (where they suffer a 100% mortality rate because I can't be bothered to make them older, they can't breed at that point anyway so it's moot.) The SRD has Human middle age at 35 and Elven middle age at 175, a couple of fermi estimates later I get Human breeding age of 14.7 and a Elf one of 73.5.
Because Drow are Evil and kill each other like it's going out of style only half of all drow born will make it to the age of 74. Because at this point I'm just doing raw estimates I'm going to give them a flat mortality rate of 0.932312147% a year.
Fertility wise I'm putting them at a birth rate that in humans would produce 1.9 children/family (6.33...%/yr).
What I found in this Extremely guessimate based simulation is that a mortality rate of 0.932312147% and a fertility rate of 6.3% gives them a stable population.
Now is where you all come in, I want any piece of information regarding Drow fertility and survival rates people can think of. I've never read the Drizzt books, which I'm sure has something somewhere in them regarding how likely it is for Drow to reach adulthood, and when adulthood is for that matter. Currently the only hard information I have comes from the Drow of the Underdark, pg 24.
The drow are notably more fertile than are their surface-dwelling cousins. They become pregnant more easily and have a slightly shorter gestation period.
This information is less than helpful seeing as I haven't found any information regarding the rate of pregnancy in surface elves, nor their gestation period.
Perhaps spurred on by these hostile circumstances, drow children develop much faster than other elves -- almost as swiftly as humans, in fact -- often beginning schooling as early as age eight or ten.
This implies that drow reach adulthood sooner than elves, but it doesn't outright state it.
Once they have reached adolescence (at about age 20, by wich time over a thrid of them have been murdered or sacrificed.)
This is actually useful, kinda. Adolescence implies the beginning of puberty. In humans (F) puberty begins at 10-11 while (M) is 11-12 ending at (F) 15-17 // (M) 16-17. For the sake of argument I'll just multiply all these numbers by 2 to get a guess for the Drow of 32 for sexual maturity. Do they start having kids at this point is another question, though that one is extremely cultural and I doubt there's any information on it in the splatbooks.
On that note, I NEED INFORMATION!!!!! Please