At what temp will eggs cook?

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simus343
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At what temp will eggs cook?

Post by simus343 »

My H. platirhinos eggs should begin to pipe tomorrow. Today, I had an egg that I knew to be a dud that I was using as a lightning rod for mold - hoping any mold would attack the already defective egg first.

I took out the dud, cut into it thinking the shell would be tough (it felt tough). The shell was actually thin and super soft, unbelievably soft. The egg white (the egg was all white, no yolk) had the consistency/texture of a hard-boiled chicken egg. I incubated the eggs outdoors, out of the sun. Ambient temps never rose above 98 Fahrenheit. Average day time temps for incubation were around 94 Fahrenheit.

Would 94 Fahrenheit be enough to basically boil and egg if kept in slightly damp vermiculite with a light covering of sphagnum?

I have my fingers crossed this didn't happen to all my eggs, and just to my dud. But, if it happened to the dud, unless it was solid early on, I see no reason why it wouldn't have happened to my other eggs as well.
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Kelly Mc
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Re: At what temp will eggs cook?

Post by Kelly Mc »

The basic theory of higher temperatures killing the embryo is that it causes the metabolic processes of the embryo to surpass the egg's diffusion of gases. Which is why defaulting to lower temperature is usually preferred.

I have heard of eggs being ok when exposed to higher temperatures of limited duration though. And stage of development probably factors in. I have done a tiny bit of experimenting with that but not as much as I would or as far as I would if I could detach more from my eggs.

Let us know what you find out.

Its a very interesting subject Simus and so much more to learn.
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Kelly Mc
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Re: At what temp will eggs cook?

Post by Kelly Mc »

If by boiling you mean non metaphorically I don't think 94 F would change the matter to a cooked material but some dud eggs are caseous inside and the texture can vary from creamy to quite firm
simus343
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Re: At what temp will eggs cook?

Post by simus343 »

Okay, so it could just be that it was a little more gelatinous all along? When the other eggs kept form, it quickly became spherical, like a turtle egg. As the others got darker, it stayed white.

Could you please explain the metabolism vs diffusion of gases a little more? I've read very little literature about egg development.

I'm guessing it's something along the lines of the metabolism releases gases which get trapped inside the egg due to not being able to escape quickly enough through super small porous openings on the shell - or something along those lines? Do you know what the excess gas does to the embryos?
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Kelly Mc
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Re: At what temp will eggs cook?

Post by Kelly Mc »

The exchange of gases ideally keep up an equilibrium of input and out put (passive diffusion) Oxygen and C02, and other waste gases possibly sulfides in late incubation. If rate of gasses exchange creates poor blood oxygen level and too much wastes gasses level embryo dies
Kfen
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Re: At what temp will eggs cook?

Post by Kfen »

Is 94 a normal incubation temperature for them? Man, that just seems high to me.
simus343
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Re: At what temp will eggs cook?

Post by simus343 »

The temps are about the same as they would be in the wild. I know females select warmer nest sites due to increased hatch rate associated with warmer incubation temperatures.

And ok, so basically normal respiration except through an eggshell instead of nares?
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Kelly Mc
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Re: At what temp will eggs cook?

Post by Kelly Mc »

No its not really like active respiration. the oxygen is carried by capillaries to the embryo by a mechanism created in the membranes in the egg, and the warmer it is the more oxygen the embryo needs, and I think the bigger the embryo gets the more it needs to exchange gasses, too. But the transport of gasses through the shell is characterized as passive diffusion so a build up of metabolic waste product gasses and not enough oxygen for the developing embryo is easily fatal. At least that's how Ive come to understand it. But I don't know if that's what happened to the egg. Perhaps it was a slug from the beginning.
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Kelly Mc
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Re: At what temp will eggs cook?

Post by Kelly Mc »

I have never heard of any snake eggs incubated in the mid 90s, or that higher temps improve hatch rates?
simus343
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Re: At what temp will eggs cook?

Post by simus343 »

It was specifically a study conducted on Eastern Hognose Snakes up in Canada. I'm not longer a student at the college whose data base I found the study in, but once I learn the data-base system of my new college I'll look the study up - I'm sure I'll be able to find it.

The females would select nest sites ranging from what I remember to be approx 28-30 degrees Celsius, or 82.4-86 Fahrenheit. My site was approx 34.44 Celsius. Eggs incubated at the higher end of the range, 86 F > 82.4 F, had a higher success rate than at the lower end of the range. While it could be coincidental, it's the only thing I've ever read that gives an "optimal" rather than "either or, whatever works". I think this would warrant a further study across a range of Colubrids, or even within one species with such a large range as Eastern Hognose.

Granted, for the study and incubation temps, this is Canada with Canadian populations in temps which may be lower on average than in Florida with Florida populations. It would make since that Florida Heterodon populations would have eggs able to withstand Celsius temp difference as much as 2-4 Celsius higher. Though, I know nothing about Canada summers.

I don't have the means to properly incubate eggs inside currently. Also, last year we at work got red rat snake eggs that were incubated in a large metal garage with temps sometimes exceeding 100 Fahrenheit during their incubation period. All of those eggs hatched just fine under the extreme incubation temps - which is why I was a little confused as to how the egg would "cook".

Part of the issue could be my having covered them "lightly" with sphagnum. "Lightly" is open to interpretation to a degree, so I may have put just a little too much sphagnum on them at the beginning. I removed some about 5-6 weeks into incubation.

Also what I meant by "like normal gas exchange" was that it was O2 / CO2 transfer along with removal of excess wastes similar to normal metabolization. The process may be different, but with intake of O2, output of CO2 and other wastes, it seems similar to me in that regard. And now that I sit here thinking on the topic, I do recall hearing about this several times before, and even being tested on it haha. I just never really learned the actual mannerism in which "hard shell eggs" go about the exchange, just mammalian embryos.
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BillMcGighan
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Re: At what temp will eggs cook?

Post by BillMcGighan »

Most hog herpetoculturists that I know use 78 to 84 degrees F. as benchmark.

Most snake nests I've found in the field, the eggs were in a cavity, underground or in a tree hollow, where humidity was higher, but the eggs were just sitting on the medium, not buried in it, including a communal Ring-necked nest of 21 eggs.

Was the study measuring the cavity temp or the surface temp?
simus343
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Re: At what temp will eggs cook?

Post by simus343 »

Cavity temps were measured. Still, on an exposed sandhill buried in a sand cavity 10cm-30cm below the surface excavated by the female, I think during mid-day the nest temp would exceed 86F. The study didn't say if 86F (30 C) was the max the nests ever hit, in all likelihood I believe it to be the average over the course of incubation.

Some of the temps are almost 70F during the day during summer, which would almost certainly be different in Florida than in Canada - I would imagine.

If these eggs don't work, sort of similar to what you described I'm going to try next time. Sand that is JUST damp enough to stick together, eggs largely exposed, humidity measured.

I incubated these outdoors in a vermiculite base because in-door temps are mid-70s. As I don't live alone, sadly I can't crank the thermostat up a few degrees.

I THINK this is the study I originally read , but not sure - all the numbers match though:
http://mysite.science.uottawa.ca/gbloui ... etPare.pdf
VICtort
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Re: At what temp will eggs cook?

Post by VICtort »

Wow, incubating in the 90's...I had no idea that would ever be successful. I am not saying you are wrong, and it may be wise to follow the data if indeed it is accurate and all variables considered. I normally incubate not higher than 82f, and in some species (Drymarchon-indigos and cribos), temps exceeding that are contraindicated, a correlation between high temps at some phases of the embryo development resulting in spinal kinks and deformities. In the Canadian study, where high temps were recorded, did the eggs cool at night? That might make a big difference, 86f for a few hours might be tolerated but not necessarily for 24/7 in an artificial incubation situation.

If I had your situation, and my goal was to hatch eggs rather than an experiment, I would keep them indoors and within an incubator if the house is routinely in the mid-70's. That might actually work out real well for some species, the ambient temps in the mid-70's OK for a long incubation. I have opposite problem with high ambient temps exceeding the desired temps, thus my incubator is often required to cool below ambient.

I incubate H.n. kennerlyi at room temps, highs of 83f in late afternoon for few hours, but cooling down to 70 or so each night. They usually hatch.

Just fooling around with a soil thermometer indicates to me that several inches below the surface is remarkably stable temperature.

Tens of thousands of eggs, including many Heterodon have been successfully hatched on vermiculite and perlite and various clay substrates. Sand is pretty dense, not sure why you would think it better? Some of us think coarse incubation media like perlite or vermiculite is desirable, allowing interstices for O2 and water vapor. You can buy an incubator pretty reasonable, you probably don't need a real sophisticated one for those Heterodon eggs. It is always good to consider what the wild population does and imitate it in a simple way, but some factors that wild snakes consider in nest selection and behaviors likely elude us, and we do the best we can based on our experience and consensus.

good luck, Vic
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Kelly Mc
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Re: At what temp will eggs cook?

Post by Kelly Mc »

VICtort wrote:It is always good to consider what the wild population does and imitate it in a simple way, but some factors that wild snakes consider in nest selection and behaviors likely elude us, and we do the best we can based on our experience and consensus.
Yes - snakes are sturdy in a broad sense, but also acutely sensitized to details that may elude us from our perspective.

Spaces, moisture, air, and matter have their own behaviors also and trying to create an optimum takes a kind of buffering of factors, not so much an imitation but a superimposition of wild situ - ie; normalcy - to a closed captive system. Be it an egg box or a vivarium.
Kfen
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Re: At what temp will eggs cook?

Post by Kfen »

VICtort wrote: In the Canadian study, where high temps were recorded, did the eggs cool at night? That might make a big difference, 86f for a few hours might be tolerated but not necessarily for 24/7 in an artificial incubation situation.
I was going to mention the same thing as above.
Also, even if your room temps are in the low or mid 70's, there are likely warmer places in your house. In the cabinet above the fridge, a closet on the south side outside wall, near the furnace/water heater/boiler etc. If you have a temp gun it is easy to find places both warmer and cooler around the house. That is of course if your current method doesn't work out. Please keep us updated.
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BillMcGighan
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Re: At what temp will eggs cook?

Post by BillMcGighan »

Vic
Just fooling around with a soil thermometer indicates to me that several inches below the surface is remarkably stable temperature.
The dramatic difference in temp in some substrate was brought home to me in west Texas one June afternoon. Air temps were already in the high 80's.
The exposed top of a flat rock that was 4" thick was recorded as 96 F. (A rock of different composition can have different results based on heat conductivity.)
The bottom of the rock (where there was a half grown Emory's rat snake) was 74 F.
The animal was cool to the touch.



To reiterate what Vic said:
Tens of thousands of eggs, including many Heterodon have been successfully hatched on vermiculite and perlite and various clay substrates.
I think most keepers find a successful method, then stick with it as a recipe. Nothing succeeds like success!


Poor man's incubator:

I've hatched virtually all major north american species of colubrids with this, except for those with eggs too large to fit well.

Plastic coffee can ( I prefer Folger's Columbian :lol: )
+ 1/3 damp sphagnum
+ 6 or 7, 1/8" holes in the top of the sides (not the plastic top - holes in the top let the humidity out).
+ placing the eggs on top of the sphagnum, not even 1/2 buried.
+ placed in a temp range 72 - 80 day/night cycle. (The cycling of temps aids the can to "breath" .)
simus343
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Re: At what temp will eggs cook?

Post by simus343 »

Lows in the study were recorded going down to the 70s yes.
That is interesting to note the differences of temps within such a close range. I use to have a temp-gun but the batteries died and I can't find a screwdriver small enough to open the battery compartment.

The reason I'm curious about sand for Heterodon is because of nesting sites being excavated by the female in a sand substrate. Obviously they do well in the wild on sand. The chambers, from what I've seen, usually have a small air pocket. However, being built in a sandy environment, rain, settling of the soil, and passing animals would all pack the soil around the eggs I would think.

- Which would raise the question: How would the eggs respirate in such a closed environment?

The answer I believe may be found in root systems and microbes that are naturally found in the soil where snakes lay their eggs.

I do intend to buy an incubator in the near future, might try to get one sometime this winter.
Also, I completely forgot about the water-heater room when I first got the eggs...completely forgot about it....that would have been the perfect spot. Warm, behind a door and away from the cats, out-of-sight, don't have to worry about large temperature fluctuations.
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Kelly Mc
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Re: At what temp will eggs cook?

Post by Kelly Mc »

I think dens and burrow sites are chosen for their proxy to desirable topographical detail. Structural form (including trees, alive or parts, plant root systems) that offer fortification and specifics of benefit to the tunnel, chamber, hole, nest. And that they choose and fashion their sites in intimate relation to its features.
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justinm
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Re: At what temp will eggs cook?

Post by justinm »

Contact Jon Vanek. He just defended his thesis on Heterodon. I'm sure he might know a little.
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