1. Welcome! Are you interested in tortoises? If so, we invite you to join our community! Our community is the #1 place for tortoise keepers to talk online. Once you join you'll be able to post messages, upload pictures of your tortoise and enclosure, and discuss any tortoise topic with other tortoise keepers. Get started today!
Dismiss Notice
Hey Guest! The 2018 Tortoise Forum Calendar is here! Click here to pre-order! Proceeds go directly to keeping TFO online and FREE for all to use! Thank you for your support!

Setting up for TDSD Study 1st question - Humidity

Discussion in 'Tortoise Breeding' started by Markw84, Dec 17, 2016.

  1. Markw84

    Markw84 Well-Known Member 5 Year Member

    Joined:
    Jan 17, 2012
    Messages:
    1,987
    Likes Received:
    2,515
    Trophy Points:
    113
    Location:
    Sacramento, CA (Central Valley)
    I am currently setting up two new incubators I have made designed to hold temperatures within 0.2 f of the set point. That is done and they are working wonderfully. I have extremely accurate sensors I place in the egg containers that will right next to the eggs that records the exact temperature and humidity within 0.1 f and 0.1% RH. It records those reading every 1 minute and provides a graph of the results I download to excel for an exact readout of conditions over the entire incubation period in one minute intervals.

    With this setup I am now questioning the best thing to do as far as humidity. Most successful breeders seem to favor the water / vermiculite 1:1 mix in a closed container with a few holes in the top of the sides. When I do that with these sensors in a simulated egg container using golf balls for eggs - I get nothing but a constant 100% humidity reading in the containers with the "eggs". There seems to be pretty unanimous consensus that no matter what medium you use - it is kept moist in the closed container holding the eggs. I cannot do that without 100% humidity.

    SO - are we saying that 100% humidity in the egg chamber is what we are trying to achieve? When I read articles and descriptions of techniques that actually measure humidity, they all seem to suggest in the 80 - 90% range. some even lower. But none of the techniques I described above that most suggest for placing the eggs produces anything but 100% humidity.

    I've always hatched eggs myself over the last two decades using the closed Tupperware style box with hole towards the top and a damp medium inside. Always had good success and high hatch rates. But never really put sensors inside before to actually MEASURE the humidity.

    With my new setups I can control the humidity of the entire incubator to any humidity level I want. So perhaps it would be better control to use open topped egg containers and control the humidity that way. But what is the desired humidity then? Are we SAYING that 80% or so sounds good, despite most all of us seem to have been using a system that actually produces 100% RH?

    Input / Comments please!

    IMG_4581.JPG


    IMG_4582.JPG
  2. wellington

    wellington Well-Known Member Moderator 5 Year Member

    Joined:
    Sep 6, 2011
    Messages:
    33,241
    Likes Received:
    9,421
    Trophy Points:
    113
    Location:
    Chicago, Illinois, USA
    (These ads do not appear for registered members.)
    Wow, love it. I have not hatched many eggs. In no way an expert, just saying what I have learned. Anyway, I was told to run 80%. My understanding, of the way I have been told and/or read is if it's too wet/high humidity, the eggs will I absorb to much moisture and will develop many cracks and go bad.
    The approx. 6 clutches I have had, only one hatched, the incubator read 75-85%, most of the time 80% which was my goal. Of course the sensor is at the inside top the lid. No idea what it would read at egg level.
    Very interesting thread.
  3. Markw84

    Markw84 Well-Known Member 5 Year Member

    Joined:
    Jan 17, 2012
    Messages:
    1,987
    Likes Received:
    2,515
    Trophy Points:
    113
    Location:
    Sacramento, CA (Central Valley)
    Thanks for the reply. Most everyone seems to "control" humidity by feel or look. That is exactly what most all experiences we have to pull from entail - No real data from a sensor where the egg is actually placed, and most all our incubators and thermometers / hygrometers are questionable as far as accuracy. Let alone temps an humidity within the incubator varying with room temps over the course of 3 months or more incubation time. Even if you read Behler's Center's Goode's paper on TDSD in Platynota, the paper qualifies it's findings with their own questions about their temperature accuracy to a degree to pinpoint the pivotal point, etc. And no humidity data. Yet most papers on TDSD often remark that Humidity as well as Temperature may play a role in triggering hormonal activity that seems to promote or subdue gonad development. So maybe some of the problems we run into with buying so many TSF hatchlings turning out to be male may be a result of lack of humidity control, or inaccurate thermometers?? So I would like to start with controlling precise humidity and make temperature the variable. But what is ideal? Most say 80% or so. Yet most all techniques I read about actually used create a 100% RH. Which is it????
  4. Yvonne G

    Yvonne G Old Timer TFO Admin 5 Year Member Platinum Supporter

    Joined:
    Jan 23, 2008
    Messages:
    70,099
    Likes Received:
    27,009
    Trophy Points:
    113
    Location:
    Clovis, CA
    How is your study going to address the timing question. I've read that sex is determined at a certain time during the process - at what temperature it is at that certain time.

    Does humidity play a role in sex determination, or just temperature?

    I've always done the seat-of-the pants method.
  5. Markw84

    Markw84 Well-Known Member 5 Year Member

    Joined:
    Jan 17, 2012
    Messages:
    1,987
    Likes Received:
    2,515
    Trophy Points:
    113
    Location:
    Sacramento, CA (Central Valley)
    So far as I've read or heard about, no one has determined if humidity ALSO plays a role, but most TDSD papers I've read speculate that it could play a role. So I want to control it to the degree to NOT make it a variable.

    I will be varying timing as well as temperatures with different groups. From my studies and experiences so far, I am leaning towards the theories that Temperature has a cumulative effect during the temperature sensitive period that seems to be highest 1/3 through incubation an lasting mostly the entire middle trimester. But with platynota, what does diapause do to that timing? And with varying diapause formulas, how does that effect it? Some of the most successful programs diapause at 65f for 30 days. Others do room temp for a week, then 65f for 4 weeks, then room temp. The Behler Center, hatching over 100 last year with only 1 not hatching - uses placing a box under the tables in one of their building, letting the eggs fluctuate from 69f to 82f for 6 weeks.

    So lots of questions to get into. A long term endeavor. But for this first post, I want to try to settle on the Humidity best to use so I can be consistent with that throughout.

    So hopefully the experienced breeders will contribute here and we can come up with an idea of the best humidity that gets the best results.
  6. wellington

    wellington Well-Known Member Moderator 5 Year Member

    Joined:
    Sep 6, 2011
    Messages:
    33,241
    Likes Received:
    9,421
    Trophy Points:
    113
    Location:
    Chicago, Illinois, USA
    Let's see if we can alert some others here. @Tom @ALDABRAMAN @allegraf @deadheadvet
    @Redfoot NERD @Neal @DeanS
    That's all I can think of off hand.

    If there is a way, while you are doing this, you could at the same time, test the humidity levels using one of the incubator type gauges and placed in the same manner as the incubator ones, but in the same container as the one you are testing, this could possibly help with comparing not only the humidity within your own setup, but your setup with others that have used the incubators and what was produced, hatch times and rates. It would give, I think, a more accurate comparison from your testing/readings to what most others are getting.
    I hope you get what I'm trying to say. Having what'd time trying to explain.
    Last edited by a moderator: Dec 18, 2016
  7. Markw84

    Markw84 Well-Known Member 5 Year Member

    Joined:
    Jan 17, 2012
    Messages:
    1,987
    Likes Received:
    2,515
    Trophy Points:
    113
    Location:
    Sacramento, CA (Central Valley)
    Sorry, Barb. You lost me! I have not seen accounts of anyone sharing what humidity they use from a gauge placed next to the eggs in the egg container itself. And if gauge accuracy is the issue, the biggest problem is variability with the same type gauges. An accurate gauge is more expensive than most choose to invest in, yet alone one small enough to go in the egg container with the eggs and produce readouts throughout the incubation to watch for fluctuations, media drying out before we check, etc, etc. Those who do cite humidity are usually talking about 80% or so, yet their very techniques for setting up the eggs produce 100% at the egg when I duplicate it.
    wellington likes this.
  8. KevinGG

    KevinGG Well-Known Member

    Joined:
    Nov 16, 2013
    Messages:
    1,005
    Likes Received:
    861
    Trophy Points:
    113
    Location:
    Santa Cruz, CA
    I know Behler Center uses closed Tupperware containers with all of their hatchlings. I never saw a humidity gauge in individual containers. Don't remember if they measured humidity inside their incubators but I imagine this would be useless with closed top containers. So if you have found that all closed top containers are kept at 100%, Behler is incubating their hatchlings at 100%. Don't know if this is new info for you or not.
  9. Markw84

    Markw84 Well-Known Member 5 Year Member

    Joined:
    Jan 17, 2012
    Messages:
    1,987
    Likes Received:
    2,515
    Trophy Points:
    113
    Location:
    Sacramento, CA (Central Valley)
    Thanks Kevin. I studied their incubator setups pretty closely and asked them lots of questions. They don't monitor humidity. Just rely on keeping the medium in the closed containers moist the same as most people talk about. They make no effort to control the incubator humidity at all since the individual egg containers are sealed. They don't monitor humidity in the containers other than " keeping it moist".

    So are we to conclude that individual containers at 100% RH is the way to go??????? Any others willing to share??
  10. KevinGG

    KevinGG Well-Known Member

    Joined:
    Nov 16, 2013
    Messages:
    1,005
    Likes Received:
    861
    Trophy Points:
    113
    Location:
    Santa Cruz, CA
    Yeah that's what I thought. I think 100% is a safe bet seeing as everyone has been successful with it. Can't imagine anyone here has done their own studies. Maybe @Will has some insights.
    Markw84 likes this.
  11. cdmay

    cdmay Well-Known Member 5 Year Member

    Joined:
    Feb 1, 2008
    Messages:
    1,794
    Likes Received:
    1,216
    Trophy Points:
    113
    Location:
    Somewhere in Florida
    Excellent thread!
    The question of humidity has also been raised by long term breeders when it comes to extra (supermumerary) scutes and other shell deformities.
    I have to admit that for many of us we incubate eggs 'by feel', for me meaning I don't know what my humidity is...but I know to look for and feel for when I open my incubators. Kind of like my grandma in Miami making fried chicken. No measurements, no timing, just knowing.
  12. deadheadvet

    deadheadvet Well-Known Member 5 Year Member

    Joined:
    Sep 5, 2011
    Messages:
    813
    Likes Received:
    811
    Trophy Points:
    93
    Location:
    Cary, NC
    I currently have 11 Platynota eggs cooling down for 45 days. I have no supplemental water trays since the containers are sealed and I periodically check to make sure there is not condensation accumulating on the inside lid. I mix 1:1 course vermiculate to water ( by weight , not volume) After 45 days, into the incubator they go. Sealed lid and I monitor condensation as previously mentioned, If there is, OI just wipe it off w/ paper towel. As far as temperature probe in the container, the container is not sealed and will affect moisture. I use a laser thermometer right into the container to monitor temp. I keep a tray of water inside the incubator to maintain humidity, but I am not measuring the humidity, If the substrate is too dry, then I add more water to the tray. Water dripping onto the eggs can lead to embryonic death, so If there is too much humidity, I would consider putting a few holes in the lid.
    Markw84 and cdmay like this.
  13. cdmay

    cdmay Well-Known Member 5 Year Member

    Joined:
    Feb 1, 2008
    Messages:
    1,794
    Likes Received:
    1,216
    Trophy Points:
    113
    Location:
    Somewhere in Florida
    I would agree with Deadheadvet, water actually dripping onto the eggs, or anywhere else in the incubator is way too much .
  14. Markw84

    Markw84 Well-Known Member 5 Year Member

    Joined:
    Jan 17, 2012
    Messages:
    1,987
    Likes Received:
    2,515
    Trophy Points:
    113
    Location:
    Sacramento, CA (Central Valley)
  15. Markw84

    Markw84 Well-Known Member 5 Year Member

    Joined:
    Jan 17, 2012
    Messages:
    1,987
    Likes Received:
    2,515
    Trophy Points:
    113
    Location:
    Sacramento, CA (Central Valley)
    Thanks so much for taking the time to reply. Very helpful. I want to hear examples like this of how people do control humidity and if they do actually measure it.

    I can, with my current setup, get any humidity I want, and am happy with the setup. I just am a bit reticent to go with the 100% is seems everyone is actually using by testing the various recommended setups. The dilemma - it seems we all tend to feel 100% RH is too high and risks embryo suffocation. Yet our recommended techniques produce 100%!!!!
  16. Markw84

    Markw84 Well-Known Member 5 Year Member

    Joined:
    Jan 17, 2012
    Messages:
    1,987
    Likes Received:
    2,515
    Trophy Points:
    113
    Location:
    Sacramento, CA (Central Valley)
    Apparently the way I chose to post above did not work. let me try again and see if I can correct the formatting....

    TMI ALERT!! If you are interested, I am posting technical thoughts/opinions here, But this is where some of my kids would start rolling their eyes!!

    Yes, that is an interesting issue I want to explore as well. From my current position, Scute placement happens before sex determination in the embryo development. Placodes form on the carapace of the embryo at about day 22 in a 90 day incubation - which sets scute placement. By day 31 the carapace scutes would be delineated. I am believing the start of the process that develops sex starts at day 25-28. At that time, the hormonal balance - in particular the production of aromatase, either will convert androgen to estrogen at higher temps, or, at lower temps, not enough conversion takes place - resulting in gonadal development. This is a cumulative effect. So the longer the yolk environment remains rich in aromatase - the more estrogen developed - female sex organ develops.

    So - the earlier conditions around and up to day 22 through 30 would be effecting scute placement and delineation, while conditions starting at day 25 and probably lasting until about day 55-60 determine sex outcome. There is an overlap, so I would theorize higher temps at day 20 or so, could lead to abnormal scutes, and start the process leading to female. This would account for why most abnormal scute tortoises are female. But high temps with a subsequent drop in temperature around day 30-40 start limiting additional aromatase production and then results in a male. Since the temperature effects of sex setting are cumulative, higher than normal early temps that would possible cause scute deformity, would require a longer, cooler environment to reverse the starting of the female cycle. That would account for why male scute deformity is relatively more rare.

    So that's my thoughts on this so far. I don't see it as a humidity issue at this point of understanding. BUT... So much yet to learn and discover!!
    Anyfoot likes this.
  17. Markw84

    Markw84 Well-Known Member 5 Year Member

    Joined:
    Jan 17, 2012
    Messages:
    1,987
    Likes Received:
    2,515
    Trophy Points:
    113
    Location:
    Sacramento, CA (Central Valley)
    EXACTLY! I have been doing the same for about 35 years now. However, I actually use paper towels as the medium I place eggs on (for at least the past 30 years now). I put in 6-8 layers of damp paper towel, then push and indentation in where I want to place the egg. Stays nice and clean. No worries about ingestion with the hatchlings. And very easy to judge moisture level. Like @deadheadvet , I have to wipe the occasional condensation off the top of the lid to avoid drips, but it's worked great for me in hatching over 1000 turtles and tortoises with 90%+ hatch rates.

    But now I would like to be more exact. Does all our humidity in the egg container hover around 100%, often creating condensation. Then drop as the medium dries until we check the eggs the next time and notice we need to add a little water??? If so what does that do to effect sex determination if anything? Or as you bring up, scute abnormality? I simply want to take that variable out of the equation. But in trying to settle on a humidity to maintain, there is very conflicting advice from the same people who actually do address humidity levels. Most all will state they believe 80% or so is ideal. To avoid 100% as it risks embryo suffocation. Yet the very techniques they promote produces 100% humidity when you actually copy and monitor their techniques. So I am repeating myself on this several times on this thread so far, but I would really like to hear from more on this. Get a consensus.

    Would love to hear from @Tom @skottip @zovick @KenS @kingsley @G-stars @Will @tortadise @ALDABRAMAN or anyone else I am not thinking of right now that has hatched a considerable number of tortoises.
  18. Tom

    Tom The Dog Trainer 5 Year Member

    Joined:
    Jan 9, 2010
    Messages:
    39,072
    Likes Received:
    15,213
    Trophy Points:
    113
    Location:
    Southern California
    In the past I used Hovbators, filled the bottom canals with water, and plugged all the vent holes in them. With this method I used 2 or 4 1/8 inch vent holes in the sides of my shoe boxes that held the eggs. This method worked well for me, but each Hovabator could only hold 2 shoe boxes of eggs, so I had to run a bunch of them. In recent years I've been using a Brinsea bird brooder chamber. This holds a much more precise temperature. It has a fan that runs continuously and I found that it was drying my media out. Now I've plugged all the vent holes in the shoe boxes and I run a tub of water directly under the fan. This works well and doesn't dry out my media now. I only add a little water to the media once or twice during a 3 month incubation period and again when hatching is imminent.

    I also use the 1 : 1 method with vermiculite and I've never tried to measure the humidity inside the shoe boxes. Humidity inside my incubator is between 80-100% on my inaccurate $10 hardware store hygrometers, for whatever that is worth. I go by feel too, and I loved Carl's fried chicken analogy! I just "know" what too dry feels like and I "know" what too damp feels like, and I adjust accordingly.

    I've hatched several hundred sulcata and leopards this way. If my first year moms have given me fertile eggs, I should see some SA leopard hatchlings in the next few weeks. Looking forward to hatching platynota this way next year!!!

    Good luck with the experiments Mark. I'll follow your results with great interest.
    Markw84 likes this.
  19. Markw84

    Markw84 Well-Known Member 5 Year Member

    Joined:
    Jan 17, 2012
    Messages:
    1,987
    Likes Received:
    2,515
    Trophy Points:
    113
    Location:
    Sacramento, CA (Central Valley)
    Thanks for the reply, Tom. This really helps!

    Looking forward to seeing pictures of those SA leopard hatchlings!
  20. Anyfoot

    Anyfoot Well-Known Member

    Joined:
    Nov 24, 2014
    Messages:
    5,515
    Likes Received:
    4,502
    Trophy Points:
    113
    Location:
    UK Sheffield
    Mark,I have little incubation experience here and much to learn, but I have noticed what you mention. My incubator reads out around 80℅. My humidity probe that I actually lay on the vermiculite touching an egg always reads 95%+. Bare in mind this is a £10 gauge, nothing fancy.
    Also, my females urinate in the nest before laying to the degree it's sloppy mud, surely that's way off the humidity chart, I would imagine over 4 or 5 months this would dry off a bit(not taking into account rainfall) Perhaps they need higher humitiy levels at the start of incubation and the humidity naturally reduces in the nest with time, or maybe the rainfall keeps it up.
    Just thoughts for you to think about.
    Markw84 likes this.
Similar Threads: Setting TDSD
Forum Title Date
Tortoise Breeding Setting up a Hova incubator Dec 14, 2016
Tortoise Breeding Help please setting up an incubator. Feb 1, 2015
Tortoise Breeding The Egg Machine-Setting Records Jul 22, 2014
Tortoise Breeding Hingeback eggs with an upsetting end! Jun 27, 2012

Share This Page