Can vary. Some of those nests you see are really just rare spawn points. At this you can see one or so an hour regularly. Then there are true nests. Its not uncommon to see two, three, or four of the same mon close by spawning regularly. With pineapples you could certainly evolve multiple fully evolved forms. Even without them you can save up a lot of candy!
Pokemon Nests
Not sure if you guys consider the Silph road nest atlas cheating, but the area where i live its pretty much useless, but lets say there is a dratini nest in a bigger city thats on their map....if i drove there, how many would you expect to catch? I usually just walk around two smaller towns to catch/hatch eggs. All of my big Mons have come from 10k eggs.......which are becoming rarer. I just read the last guys thread how he hatched 15 Machamps via Machop nest....so was just wondering, how do nests work?
Answers
Some may say using any third party tools to find Pokémon is cheating.
Some may say using the Nest map is not cheating even though it is telling the player where the exact Pokémon they are looking for is spawning frequently for the next 14 days.
Nests are where a specific type of Pokémon gather. Normally they will spawn about 6 at once in a small area which is usually parks.
Elite Pokémon and crap pokemon and region exclusives (IIRC) do not have Nests. So there are no
Draini
Lavatar
Chansey
Snorlax
Piggey
Weedle
Caterpie
Zubat
As a side note,if you age looking for dratini check a water biomedical the spawn psyduck and magikarp frequently.
My closest nest has 3 spawn points that can regularly have 2 spawns to catch, and on rare occasions all 3 spawns are active...but there are times that you need to wait half an hour just to catch one of the nesting mons.
Then there are 2 other nests close, that are over a larger area, and these will have at least 3-4 of the nesting species at any given time, and can go as high as about 10 over the whole area, and spending a couple of hours there will give you enough to evolve.
So it depends on the nest.
Once you have been to a nest a couple of times you can tell how productive it can be.
As for the dratini nest you mention...there is no such thing.
And no...I don't consider sharing nest locations on Silph to be cheating in any way...and neither do Niantic.
That sounds more like a regular spawn point.
There are some spawn points that seem to spawn the same selection of mons, and sometimes you can be lucky enough to find a point that spawns a very desirable mon on a regular (or semi regular) occasion.
These can be handy, because when the nest changes occur every 2 weeks, the regular spawn points won't change - so you can keep going there and getting the same mon again and again.
Sounds to me like you have found a semi regular spawn, that has dratini as one of it possibile spawns.
Nests change...regular spawn points can be consistent over a longer time period.
dratini do not nest as others have said but sometimes people will put a marker down at places were they regularly find them. The closest such place to me gives me one dratini if I spend an hour there between say 1900-2100 sometimes 2 sometimes 0. It fortunately has a number of stops in close proximity and a fairly dense nest (bellsprout at the moment which kind of sucks)