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Dwarf Fortress => DF Dwarf Mode Discussion => Topic started by: DragonThrall on April 02, 2012, 12:34:46 pm

Title: Egg hatching time science
Post by: DragonThrall on April 02, 2012, 12:34:46 pm
Before trying to hatch some rocs, I decided to do some research as rocs have an eggsize of 200k. For the study, I used chickens and modified the tags [CHILD:X] (Age to mature), [EGG_SIZE:X] and had chickens grow at birth using [BODYSIZE:0:0:X]. If nothing hatched after a year, I aborted the game. Here are the findings:

Bodysize      Eggsize     Age to mature     Time to hatch in months
10001003
10005003
100015003
100025003
10005000-
10000100-
100005003
1000015003
1000025003
100005000-
1000000100-
10000005003
100000015003
100000025003
100000050003
10001013
10001023
1000105-
100010103
1000103
100050003

Tl,dr: the result is quite surprising, regardless of parameters, chicks hatched either exactly three months after the eggs were laid or not at all. The latter seems to be due to some random factors, as sometimes a set of eggs hatched, sometimes they did not.

Most importantly:
Eggsize and bodysize are not correlated with time to hatch, at least in chickens.
Title: Re: Egg hatching time science
Post by: Girlinhat on April 02, 2012, 12:40:14 pm
More likely, there's a lower limit of 3 months.  Try changing it into the thousands of eggsize, you'll probably see results.  It's just that "anything shorter than 3 months is rounded up".
Title: Re: Egg hatching time science
Post by: Naryar on April 02, 2012, 12:46:19 pm
yeah, try egg sizes superior to 500 now. This is good anyways, post it on the wiki after !

Also it seems that bodysize does not influe egg hatching time.

Title: Re: Egg hatching time science
Post by: DragonThrall on April 02, 2012, 12:48:56 pm
Actually cave crocodiles have an eggsize of 80. I don't know if there is a common creature with bigger eggs. This would mean nearly every creature hatches after three months of time, except for the megabeasts?

EDIT:
Tried with eggsize 10k. Still three months. However: Out of twenty roosting hens, only three gave birth to chicks after that time. So possibly higher eggsize reduces chances of hatching?
Title: Re: Egg hatching time science
Post by: Girlinhat on April 02, 2012, 01:00:24 pm
Well then what's the hatching time of 200k?
Title: Re: Egg hatching time science
Post by: Sphalerite on April 02, 2012, 01:01:01 pm
Need more information on your experimental setup.

Are you generating a new world each time you change the numbers?

If not, are you changing the egg size of the raws in your region folder, rather than the general folder?

Are you starting over with a new batch of chickens every time you change the values?
Title: Re: Egg hatching time science
Post by: DragonThrall on April 02, 2012, 01:03:03 pm
Dragons have an egg size of 6100 :P. Imagine what these poor chickens have to suffer. And I generate a new world each time, even quitting DF between runs to be sure to load the new raws. And yes, I modify the DF/raws folder.
EDIT:
At eggsize 1000000, time to hatch is still three months.
Title: Re: Egg hatching time science
Post by: NonconsensualSurgery on April 02, 2012, 01:22:33 pm
Eggs do sometimes randomly fail to hatch. I would have guessed 50% failure, but your data suggests only 25% failure.

This is interesting and noteworthy by itself.

(drop [COMMON_DOMESTIC] into rocs, strip out megabeast tags and see what happens)
Title: Re: Egg hatching time science
Post by: DragonThrall on April 02, 2012, 01:28:39 pm
After precisely three months, I get roc hatchlings. So it seems that egg hatching time is always exactly three months, not really depending on anything.
EDIT: 8/20 hatched. So perhaps stats influence egg hatching chance after all.
Title: Re: Egg hatching time science
Post by: Sphalerite on April 02, 2012, 01:32:58 pm
Interesting.  The question now is, does the EGG_SIZE tag actually do anything at all?
Title: Re: Egg hatching time science
Post by: DragonThrall on April 02, 2012, 01:39:37 pm
Right now, all roc eggs have hatched, however it took them up to six months.

My theory is the following: All fertilized eggs hatch precisely after three months.

Let me outline my experiments in detail:
For the first few experiments, I created several different chicken species and embarked with one female and one male. Later on, when changing egg sizes only, I took up to forty females and twenty males. Noticably lower hatching rates after three months.
Now, I took five male rocs and twenty female ones.

The stunning revelation:
All twenty females gave birth. However, it took for some longer to hatch, some up to six months after the eggs were laid.
So possibly eggs are not instantly fertilized. Depending on the hatchery setup/male availability, it takes some time for all of the eggs to be fertilized. And three months later, they hatched.
Title: Re: Egg hatching time science
Post by: Wannazzaki on April 02, 2012, 01:40:02 pm
It causes a situation that looks something like this

Spoiler (click to show/hide)
Title: Re: Egg hatching time science
Post by: i2amroy on April 02, 2012, 03:28:34 pm
Quote from: Sphalerite on April 02, 2012, 01:32:58 pm
Interesting.  The question now is, does the EGG_SIZE tag actually do anything at all?
Weight possibly? Maybe it would control how much food you would ever get if you managed to somehow "butcher" an egg.
Title: Re: Egg hatching time science
Post by: nightwhips on April 02, 2012, 04:43:27 pm
Is weight not a factor during cooking?
Title: Re: Egg hatching time science
Post by: Sphalerite on April 02, 2012, 04:58:10 pm
Quote from: nightwhips on April 02, 2012, 04:43:27 pm
Is weight not a factor during cooking?

Not in the slightest.  Roc eggs and chicken eggs yield exactly as much food per egg when used as cooking ingredients.  My attempts to build a roc egg farm were a great disappointment.
Title: Re: Egg hatching time science
Post by: Garath on April 02, 2012, 04:59:02 pm
the meals might weight more though.
Title: Re: Egg hatching time science
Post by: Greiger on April 02, 2012, 09:31:17 pm
I always thought the eggsize just had an effect on the weight of the egg, I kinda figured size made no difference in hatching time from my own experiences, but my egg science always had to do with civ creatures laying eggs and not just general egg science and never got around to really testing hatch times under controlled conditions.

Always good to see science disprove common belief, wish we had more data on exactly how egg fertilizing worked though.  The eggs that took up to 6 months, were they all 3 or 6 months or did some end up at 4 months, some at 5 months?  If it was 3 or 6 and nothing in between that might mean critters only send out spores once a season.
Title: Re: Egg hatching time science
Post by: Tierre on May 15, 2012, 09:42:17 am
in http://dwarffortresswiki.org/index.php/Time it is said that egg_size determines time to hatch. But tests show otherwise.
Title: Re: Egg hatching time science
Post by: Akura on May 15, 2012, 11:47:45 am
I guess [EGG_SIZE] really just determines the size of the egg item. Normally, the items created from animals have sizes and weights determined by the original creature(weights derive from creature materials, I think). Younger creatures are smaller, resulting in smaller and lighter animal products. I think eggs are handled differently, since animals that aren't fully grown but otherwise mature lay the same-size eggs, requiring [EGG_SIZE].

If eggs remain on abandon, perhaps you could create a fort, lay both chicken and roc eggs, abandon, then send an adventurer to pick up the eggs, then use them as weapons to see if larger eggs are better.
Title: Re: Egg hatching time science
Post by: Loud Whispers on May 16, 2012, 11:58:02 am
Whelp. The modding forums have been defeated :O