# Hermanns: Incubation



## RGB

Hi, I have had an adult Hermann that I had been breeding for one season and any fertile eggs were incubated with about 75% success rate. This spring, I obtained a 2.5 colony from a longtime breeder and have begun getting a few clutches of eggs, most of which are infertile. The eggs that are fertile (chalked and showed vessels on illumination) are probably only hatching 25%. I retrieve eggs almost immediately, most are laid outside in the ground. My incubation technique has been dampened vermiculite and the humidity has been 80-85% with temp of 30'C. I've checked with several thermometers. I'm going to begin incubating on near dry vermiculite with humidity of 70%. I'm not sure what else to try. It seems like my eggs "dry out" with large bubbles forming quickly which is why I tried the higher humidity, but it never made any difference. 
This may just be the difficulties of new torts in a new environment for the first season, not making beautiful eggs, but I'm not convinced I don't have a bigger problem. I feed predominately weeds and mazuri chow, with calcium carbonate sprinkled regularly.

Any thoughts? Any questions I need to ponder? Any constructive advice?


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## GBtortoises

Are you sure that the hygrometer that you're using to monitor the humidity level is accurate? Are the thermometer & hygrometer kept in the incubator at all times or are they placed in it periodically to check levels? Ideally, they should remain in the incubator at all times for accuracy.
For years I have consistently incubated Hermann's eggs as well as most other Testudo eggs at about 31.2 (88f)-31.7 (89f) at 75-90% ambient humdity with very good sucess. I use perlite rather than vermiculite. I dislike vermiculite because it is so unstable. When it gets too dry it draws moisture from the egg where they are in contact. When it gets too wet it does not allow air exchange around the egg where it contacts it and often ends up causing the egg to develop mold at the contact point. To maintain correct humdity levels within the incubator I use seperate containers of water with a sponge in them to act as a wick to help disperse the moisture better.


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## RGB

Thanks so much for the response....

I leave thermometers and hygrometers in the egg containers in the incubator constantly. I'm thinking humidity is my problem. Multiple hygrometers range about 10% between the high and low readings.... So its difficult to know exactly my humidity. I have an ambient humidity in the incubator of around 60% with pans of water in the bottom of the incubator. And I have been keeping the eggs on pretty much dry vermiculite. I've read to mix vermiculite 50/50 with water by weight, but that seems way to wet to me. I have been placing a few drops of water in corners of egg containers away from the eggs until the hygrometers read 75-85%.

Does this sound like a poor set up?

Maybe I need to keep the vermiculite wetter?
I could switch to perlite, how do you know how much water to add to perlite?

I could add sponges and raise the overall humidity.

Thanks again!


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## GBtortoises

Like I mentioned above, the reason I dislike vermiculite is due to it's instability. It dries out too rapidly or retains too much moisture based on the environment (humdity & temperature) that it is in. It is very inconsistent. In reality the incubation medium should not be what controls the moisture level within the incubator. The heat and humdity source should. You can incubate eggs that are sitting on a dry surface, not surrounded by any medium if the temperatures and humdity level within the incubator are suitable for incubation. Incubation medium only needs to hold the eggs in place if the conditions (again temperature & humidity) are adequate within the incubator while allowing good air exchange without adding or taking away moisture from the egg. Vermiculite does exactly that where in contact with the egg, adds or takes moisture away because it has a wick effect. 

You do not need to add water to perlite. It can be used "as is" out of the bag. The moisture (humidity) should not be supplied by the medium, but by a seperate water container within the incubator. It works more efficiently if the open water container has a sponge floating on top or standing up in it to help wick air out of the container and throughtout the incubator.

Another factor in incubation is where it is located. If it is in an area that is considerably drier than the level that you're trying to maintain within the incubator you'll have a harder time keeping the desired humidity level within that incubator. If it's in an area that is much cooler (or warmer) than the temperature that you'r trying to maintain within the incubator it will effect the temperature within the incubator. Any areas where the temperatures and humidity fluctuate considerably will effect the levels within the incubator too. It works best to place the incubator in an area that is consistently 10 or 15 degrees cooler than the temperatures being maintained within the incubator.


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## RGB

Thanks so much.

I will follow your advice! That should help hatch more of my fertile eggs.

Now I just have to hope that with time the colony will adjust to new surroundings, and the fertility rate will go up. And with more experience i can create better egg laying conditions (i wonder if a few clutches have been held too long as a few of the eggs have un evenly calcified shells). It would be hard to determine if I received some infertile males. 

Thanks again for the great advice!


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## GBtortoises

RGB-The photo below is the incubator set up that I am referring to:


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## RGB

Ok
I have had a hard job creating greater than 60% humidity in my incubator, but I'll just add even more water buckets and try adding sponges.

So...
1. Eggs in dry perlite, no need for lids on containers
2. humidity supplied by water tub/sponge
3. Temp= 31'C
4. Humidity= 75-85%
5. keep incubator in stable environment with temp of approx 20'C 

I am nervous about moving my current viable eggs, but I guess I probably should be ok if I do it very carefully without shaking or turning them. 

I appreciate the very helpful information!


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## GBtortoises

If you are having a hard time maintaining a humdity level within the incubator above 60% you may want to look at how well the top is sitting on the base. It may be allowing too much air/moisture to escape. Might it be located in an area that is very dry? This would also cause the incubator to have a difficult time maintaining a higher humdity. What type of incubator is it?


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## RGB

It's a reptibator. It has been excellent at maintaining very consistent temps. I have it in my basement which is 20'C and about 50% humidity.
I note that yours does not have any obvious air holes in the bottom, mine has air holes in the bottom that facilitates air flow from the bottom up through. Maybe I should tape those off and restrict the airflow as it probably is reducing my ability to raise humidity. I'd love to experiment with these things, but it's hard to play around too much when I have 5 chalked eggs in there. On the other hand, to do nothing to improve and hatch only a couple of them would be equally disturbing!


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## GBtortoises

I bought a couple Reptibators to try them a few years ago when they came out. They're terrible at holding humidity because the top doesn't form a good enough seal with the base. I adhered an inexpensive foam weatherstripping to the top rim of the base and they work much better. They produce the heat well, just don't hold it or the humidity in. The other incubators I use are good old, simple Hovabators.


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## Tom

GB, Do Testudo babies eat the incubation substrate right after hatching?

I ask because my sulcata hatchlings do. I pop them into brooder boxes as soon as they step out of their eggs, but they still ingest a fair amount of vermiculite while they are working on getting out of the egg. When I finally see their first poops, a couple of weeks later, there are the unmistakable shiny flecks of vermiculite in them. They seems to pass the vermiculite just fine, but when I bought some from another breeder that were incubated on perlite, necropsy revealed that they were blocked up with the perlite.

Everything you are saying about the perlite makes great sense, so I'd like to use that for Testudo eggs when the time comes, but I'm understandably nervous about it, given my history with it.


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## Tortoise

Gary
Should I incubate my red foot eggs on dry perlite too-I have them on perlite with 1 part water so far. My Russian eggs are on dry perlite though and seem to be developing so far

thanks


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## GBtortoises

Tom said:


> GB, Do Testudo babies eat the incubation substrate right after hatching?
> I have never seen any evidence or indication that the babies consume any of the incubation medium. They get a little covered with the dust of it if they burrow down into it, but that's it. I have also never seen evidence of them consuming their eggshell in the incubator. But they do occasionally once placed in the brooder. My brooder is an incubator that I maintain at about 84 degrees. It contains a large sphagnum moss filled container that is kept very moist by spraying and an additional open container of water the same as within the incubator. I place newborn tortoises into the moss within the brooder as soon as possible once they're fully out of the egg. In between the incubator and brooder transfer I place them in a tempid container of shallow water and allow them to drink. I crumble the remaining eggshell up and place on top of the moss. I keep them in the brooder for an average of 3 days. When they come out of the brooder and into a regular enclosure their yolk sacs are always absorbed and the seam nearly completely closed. They also have almost completely "unwrinkled" from the shape that they are when first hatched.
> 
> 
> I ask because my sulcata hatchlings do. I pop them into brooder boxes as soon as they step out of their eggs, but they still ingest a fair amount of vermiculite while they are working on getting out of the egg. When I finally see their first poops, a couple of weeks later, there are the unmistakable shiny flecks of vermiculite in them. They seems to pass the vermiculite just fine, but when I bought some from another breeder that were incubated on perlite, necropsy revealed that they were blocked up with the perlite.
> 
> Everything you are saying about the perlite makes great sense, so I'd like to use that for Testudo eggs when the time comes, but I'm understandably nervous about it, given my history with it.


Nowadays the majority of long time tortoise breeders along with several snake and lizard breeders use perlite, Hatchrite (which is just hydro-infused perlite) or the Repashy Super hatch. I tried the Repashy brand incubation medium which is basically a clay product and found it to work terrible with tortoise eggs if used per the instructions on how to hydrate it. For many years, way back to the early 80's I used vermiculite and have never been very happy with it's stability. I've tried different soils, foam and probably a few other things that I cannot recall. Above and beyond all of them perlite has resulted in the desired and most productive results.




Tortoise said:


> Gary
> Should I incubate my red foot eggs on dry perlite too-I have them on perlite with 1 part water so far. My Russian eggs are on dry perlite though and seem to be developing so far
> 
> thanks


I certainly can't decide that. All I can say is that I have experimented with a lot of different incubation mediums and incubation methods over the years and have realized that the medium itself does not need to be and probably should not be wet. The humidity should come from the air within the incubator by means of a source separate from the medium that is in contact with the eggs. I don't know what the maximum humidity range is that can be reached by this method but I know that I my own incubators reach as high as 88% ambient humidity within the incubators if I let them. So with that kind of moisture why would you need to place the eggs in a damp medium? I have never dug up a nest outdoors and found the eggs sitting in wet soil. Even when the eggs are a poorly built nest that does not have an air chamber but is packed solid with soil. The soil obviously does contain some moisture. But it is by no means damp or wet. Just my observations.


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## RGB

I have blocked off nearly all air holes in the reptibator incubator (both top edge and in the bottom.... And there are a lot of them). Increased the water reservoir in the bottom, and added a sponge. The humidity has now been around the 75-78% mark during the day... 70% at night (my tortoise room cools down at night when all the heat lamps go out. Must somehow affect the incubator due to the changing temp in the room- something i didn't consider before)....

Does this sound sufficient? 
Still seems kind of low!
If not, I could try covering every hole in the bottom, getting a better seal for the top, or just buy a new incubator.

Great feedback guys, I much appreciate it. 

PS. I have witnessed a baby hermann half hatched (half still in egg) eating the vermiculite. It did fine. Only saw it once, and I have only had limited experience.


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## Baoh

Tom said:


> GB, Do Testudo babies eat the incubation substrate right after hatching?
> 
> I ask because my sulcata hatchlings do. I pop them into brooder boxes as soon as they step out of their eggs, but they still ingest a fair amount of vermiculite while they are working on getting out of the egg. When I finally see their first poops, a couple of weeks later, there are the unmistakable shiny flecks of vermiculite in them. *They seems to pass the vermiculite just fine, but when I bought some from another breeder that were incubated on perlite, necropsy revealed that they were blocked up with the perlite.*
> 
> Everything you are saying about the perlite makes great sense, so I'd like to use that for Testudo eggs when the time comes, but I'm understandably nervous about it, given my history with it.



This is not true. Why do you feel compelled to keep making revisions to your "story"?


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## GBtortoises

RGB said:


> I have blocked off nearly all air holes in the reptibator incubator (both top edge and in the bottom.... And there are a lot of them). Increased the water reservoir in the bottom, and added a sponge. The humidity has now been around the 75-78% mark during the day... 70% at night (my tortoise room cools down at night when all the heat lamps go out. Must somehow affect the incubator due to the changing temp in the room- something i didn't consider before)....
> I don't think a humidity level in the 75% range, give or take a few percent is bad at all. I can't add much about the drop in humidity except that I have tried to keep incubators in my tortoise room in the past thinking the heat from within the room would help with ambient heat. All it did was what you are experiencing, cause the humidity within the incubator to drop. Mine are set up in another, unheated area of my basement. The ambient heat in that area is always about 62-64 degrees so the incubators have a constant to operate within. The humidity remains within the desired range that I want to maintain despite the basement having a dehumidifier running in it 24/7 during the summer months. I really believe that the temperature stability goes hand in hand with creating humidity stability.
> 
> Does this sound sufficient?
> Still seems kind of low!
> If not, I could try covering every hole in the bottom, getting a better seal for the top, or just buy a new incubator.
> 
> Great feedback guys, I much appreciate it.
> 
> PS. I have witnessed a baby hermann half hatched (half still in egg) eating the vermiculite. It did fine. Only saw it once, and I have only had limited experience.


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## RGB

I followed the advice and so far so good...
I hatched two beautiful hermanns the other day. I also have about 10 eggs that are anywheres from just chalking to due to hatch in 10days, all of these appear to be developing/progressing well except for one that stopped very early in process. It would be super exciting to hatch 11/12 fertile eggs... Fingers crossed!

I'm still getting many eggs that are infertile but that seems to be a completely different issue!

I'll keep posted in a couple months with Update on remaining eggs...
Thanks
Bob


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## RGB

12 consecutive fertile eggs have now hatched!

As conclusion to this post: Thanks for the advice!!!!!!


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## TortieLuver

Wow that's awesome


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