# Incubation time



## Yellowtail (Nov 17, 2018)

Just had a clutch of Darwins hatch 3 days earlier than expected and I think it may be because in late
October I had an Airconditioning breakdown (Samsung) during a hot period and temps in my snake room went to 34 C for a few hours each day until I could get it fixed under warranty, a temporary portable A/C helped but could not cope in the hot part of day. My incubator is set at 31C and normally Darwins hatch at 58 days, this lot started poking their heads out at 55 days.
They all came out in a few hours without any assistance and appear ok, it will be interesting to see if other clutches due over next few weeks are similarly affected.
Any expert or experienced comments welcome.


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## Flaviemys purvisi (Nov 17, 2018)

Seems like a legit natural response to your periodically increased incubation temps. I know this isn't exactly the same but I know of a turtle breeder who conducted his own experiment and incubated 2 separate clutches of _Emydura macquarii signata_ - Brisbane River turtle eggs, one at 24°C and one at 30°C. The clutch incubated at 24° took 78 days to hatch, the clutch incubated at 30° took 42 days to hatch. There were no difference in the sizes of the hatchlings or their vigour, both clutches were bright, fit and alert. A normal optimum incubation temp for most freshwater turtle eggs is 28° and _signata_ incubated at this temp hatch at 54 days.

I'm currently incubating _Chelodina longicollis_ eggs which normally (with natural day/night temp fluctuations would take anywhere up to 122-180 days to hatch. My incubator is keeping them at 28° (provided I have no aircon failures like you did) they _could_ start appearing as early as day 65-67.

I would expect that you will have a few other heads poking out of their eggs a little earlier than expected without any negative outcome.


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## Sdaji (Nov 17, 2018)

55 days isn't unusual for Carpets. Either way, looks like you got some good results 

Flavi: I haven't incubated a huge number of turtle eggs, but I did split one clutch of Chelodina longicolis between an incubator and leaving them on the shelf at room temperature. Not surprisingly the ones in the incubator hatched much more quickly, and the ones on the shelf took a much longer time. I don't have the data handy (it's in a notebook in storage back in Australia), but after a very long time I put the eggs on the shelf into the incubator and within about 4 days they hatched, which I'm guessing meant they fully developed then sat there in the eggs waiting until spring, which the incubator simulated, making them assume it was a good time to come out.

They were all strong and healthy, but the colours were very different. One lot (I think it was the incubated clutch) had muted colours, while the cold clutch came out with the brilliant bright orange patterns.


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## Pauls_Pythons (Nov 17, 2018)

Its an interesting subject YT and one that will always bring a range of responses.
IMO incubation temps can go high at times and have little to no effect on the offspring, other than, as in this case bring on earlier than expected hatching. 
That said I had a similar problem with an aircon a few years ago and had at that time 4 clutches in the incubator at various stages of development. 2 of those clutches hatched out with no noticable change from normal other than being a day or 2 early, a 3rd clutch contained animals that were normal but undersized, most everyone of those animals failed to fully absorb the egg sak. (Same pairing has been done several times since then and never had this problem re-occur). The 4th clutch emerged with some being deformed. From memory 2 had short tails, one a tail kink and another was quite severely kinked though survived and had to be euthanased. 
I have not done that pairing again since, though both parents have bred normal hatchies with different partners. Was it due to genetics or temperature, my gut says it was the temperature spike.

My point is that I think it depends at what stage in the embryo development the temperatures change. If it happens to be late in the development stage there would be little to no impact on outcome, temps going to 34 might not be sufficient but I do believe that temp spikes at critical stages of the embryo development can bring about deformities that are sometimes incorrectly considered to be due to genetic issues rather than incubation/husbandry issues.


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## Flaviemys purvisi (Nov 17, 2018)

Sdaji said:


> 55 days isn't unusual for Carpets. Either way, looks like you got some good results
> 
> Flavi: I haven't incubated a huge number of turtle eggs, but I did split one clutch of Chelodina longicolis between an incubator and leaving them on the shelf at room temperature. Not surprisingly the ones in the incubator hatched much more quickly, and the ones on the shelf took a much longer time. I don't have the data handy (it's in a notebook in storage back in Australia), but after a very long time I put the eggs on the shelf into the incubator and within about 4 days they hatched, which I'm guessing meant they fully developed then sat there in the eggs waiting until spring, which the incubator simulated, making them assume it was a good time to come out.
> 
> They were all strong and healthy, but the colours were very different. One lot (I think it was the incubated clutch) had muted colours, while the cold clutch came out with the brilliant bright orange patterns.


Hi Sdaji, that is not surprising as _longicollis_ are known to over winter in their nest (if the clutch was laid late in the season) before emerging in spring so that's exactly what's happened there. The colour difference (I'm assuming on the plastron) is very interesting though... especially since you split a clutch and they were not separate clutches. You must have kept them at a reasonable temp on your shelf because below 22° the embryos would have died.


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## Sdaji (Nov 18, 2018)

Flaviemys purvisi said:


> Hi Sdaji, that is not surprising as _longicollis_ are known to over winter in their nest (if the clutch was laid late in the season) before emerging in spring so that's exactly what's happened there. The colour difference (I'm assuming on the plastron) is very interesting though... especially since you split a clutch and they were not separate clutches. You must have kept them at a reasonable temp on your shelf because below 22° the embryos would have died.



Yeah, I was sure they must overwinter, but I thought it was cool that they were obviously sitting there ready to hatch and came out when they were triggered by an environmental cue, rather than when they were ready.

They got below 22 degrees on the shelf and I don't believe you can easily find a place to bury eggs near waterways in southern Australia where they won't go below 22 degrees during all of winter.
[doublepost=1542467084,1542466807][/doublepost]


Flaviemys purvisi said:


> Hi Sdaji, that is not surprising as _longicollis_ are known to over winter in their nest (if the clutch was laid late in the season) before emerging in spring so that's exactly what's happened there. The colour difference (I'm assuming on the plastron) is very interesting though... especially since you split a clutch and they were not separate clutches. You must have kept them at a reasonable temp on your shelf because below 22° the embryos would have died.



Yeah, I was sure they must overwinter, but I thought it was cool that they were obviously sitting there ready to hatch and came out when they were triggered by an environmental cue, rather than when they were ready.

They got below 22 degrees on the shelf and I don't believe you can easily find a place to bury eggs near waterways in southern Australia where they won't go below 22 degrees during all of winter.

And yep, I'm talking about the plastron  I've seen wild ones (I was once lucky enough to spot one making its way from the nest to a pond!) and for memory they did have the bright orange colour, and for memory it was the cool temperature ones I incubated which came out with the bright colours. I'm not 100% sure on which way around it was, but it was definitely 100% split between the temperature treatments, and there was no variation within the treatments, so I'm highly confident the temperatures changed the colour. If I was breeding them again I'd definitely investigate further, but I doubt I'll ever work with them again. Someone else definitely should.


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## Flaviemys purvisi (Nov 18, 2018)

Sdaji said:


> They got below 22 degrees on the shelf and I don't believe you can easily find a place to bury eggs near waterways in southern Australia where they won't go below 22 degrees during all of winter.


I'm sure the fully developed and ready to hatch neonates on your shelf and the ones in the wild experience temps below 22°C whilst waiting for the spring thaw (hence them hatching after just 4 days after you put them in the incubator), but not the developing eggs... during the critical stages of development. The eggs are laid from late September to January, sometimes as late as February. The hatchies in nests laid late in the season will often delay emerging until spring. Incubation temps of nests or the ones on your shelf wouldn't fall below 22° (unless that shelf was one in your refrigerator - or you weren't being aircon smart)   that time of the year and if they happened to over night or in the wee hours of the morning, it wouldn't be for long. The _longicollis_ eggs wouldn't develop whilst constantly below 22°. The little turtles that over winter however would simply brumate, enter a prolonged period of torpor in the nest.

There is a species of turtle though; _Macrochelodina expansa_ - Broad shelled turtle that lays its eggs in autumn (March-May) and they experience a diapause - (period of suspended development) over winter and continue to develop when spring arrives hatching after 192 days. Artificially incubated _expansa_ eggs also must go through this diapause by switching the incubator off entirely for at least 4-6 weeks or they will not hatch if continuously incubated. The record for broad shelled turtles that hadn't emerged from their nest is 664 days, after the eggs were deposited. On day 664 the nest was excavated and all the baby broadies were alive and well, the cap of clay soil sealing their nest had turned as hard as concrete and they couldn't emerge themselves.

Whilst _expansa_ eggs go through a diapause over winter, this is not the case for _longicollis_. Their developing eggs don't over winter, only the ready to emerge hatchies sometimes do.


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## Yellowtail (Nov 18, 2018)

Thank you for the responses and they more or less confirm my thoughts on the situation, the overheating event was late October and quite late in the development of all my clutches except for one lot of Darwin eggs due to hatch late December so it will be interesting to see how they were affected. I have now closely examined the recent lot and they all appear healthy, active and normal.
I have hatched several clutches of Darwins each year for 12 years now always using the over water method and the incubation period has always been 58 - 60 days with a hatching period of only a few hours from the first head appearing to the last exiting the egg, I leave the eggs in the clump as laid and never pip any. They mostly hatch over night with most out by the time I find them in the morning, the hets always come out before the albinos, they appear more cautious and will have a good look before emerging.
Without stirring up the debate about almost all carpet python species being genetically identical why does the incubation period vary so much (50 - 63 days between species) and I am not including Morelia Oenpelli that I have never bred and apparently incubate for 100 days. It is not just a climate - locality thing or coastals and jungles would be the same, my julattens are always 62-63 days.


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## Sdaji (Nov 18, 2018)

Flaviemys purvisi said:


> I'm sure the fully developed and ready to hatch neonates on your shelf and the ones in the wild experience temps below 22°C whilst waiting for the spring thaw (hence them hatching after just 4 days after you put them in the incubator), but not the developing eggs... during the critical stages of development. The eggs are laid from late September to January, sometimes as late as February. The hatchies in nests laid late in the season will often delay emerging until spring. Incubation temps of nests or the ones on your shelf wouldn't fall below 22° (unless that shelf was one in your refrigerator - or you weren't being aircon smart)   that time of the year and if they happened to over night or in the wee hours of the morning, it wouldn't be for long. The _longicollis_ eggs wouldn't develop whilst constantly below 22°. The little turtles that over winter however would simply brumate, enter a prolonged period of torpor in the nest.
> 
> There is a species of turtle though; _Macrochelodina expansa_ - Broad shelled turtle that lays its eggs in autumn (March-May) and they experience a diapause - (period of suspended development) over winter and continue to develop when spring arrives hatching after 192 days. Artificially incubated _expansa_ eggs also must go through this diapause by switching the incubator off entirely for at least 4-6 weeks or they will not hatch if continuously incubated. The record for broad shelled turtles that hadn't emerged from their nest is 664 days, after the eggs were deposited. On day 664 the nest was excavated and all the baby broadies were alive and well, the cap of clay soil sealing their nest had turned as hard as concrete and they couldn't emerge themselves.
> 
> Whilst _expansa_ eggs go through a diapause over winter, this is not the case for _longicollis_. Their developing eggs don't over winter, only the ready to emerge hatchies sometimes do.



Mate, I slept in that room at the time, I kept reptiles in there, I had literally about a dozen thermometers in various positions there (I'm prone to it, in the room I'm in now I can see several thermometers from where I'm sitting) it routinely got below 22 degrees right from day one. It was a small, uninsulated bungalow in Melbourne with a raised floor (temperatures crashed at night).There were days where the maximum scarcely went above 22 degrees inside the bungalow and didn't get there outside. I watched the eggs being laid and they were in the bungalow shortly after. I'm not familiar with the thermal limits of eggs, but I definitely know those ones routinely spent a lot of time below 22 degrees and all hatched. I would be very surprised if I buried a thermometer by a pond in Melbourne and it didn't routinely fall below 22 degrees overnight, but I know what happened with these eggs.


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## Flaviemys purvisi (Nov 19, 2018)

Sdaji said:


> Mate, I slept in that room at the time, I kept reptiles in there, I had literally about a dozen thermometers in various positions there (I'm prone to it, in the room I'm in now I can see several thermometers from where I'm sitting) it routinely got below 22 degrees right from day one. It was a small, uninsulated bungalow in Melbourne with a raised floor (temperatures crashed at night).There were days where the maximum scarcely went above 22 degrees inside the bungalow and didn't get there outside. I watched the eggs being laid and they were in the bungalow shortly after. I'm not familiar with the thermal limits of eggs, but I definitely know those ones routinely spent a lot of time below 22 degrees and all hatched. I would be very surprised if I buried a thermometer by a pond in Melbourne and it didn't routinely fall below 22 degrees overnight, but I know what happened with these eggs.


Fair enough mate, I've spent very little time in Melbourne. It must have been a very cool summer though for the eggs to have spent substantial time below 22°. Heh heh #bungalowlife Despite my scepticism, Without having all the exact data of the daily temps and just as importantly, the humidity levels your "shelf eggs" were exposed to, it's difficult to argue with you. 

I certainly wouldn't attempt to incubate longicollis eggs at 22° or below, the success rate would be substantially diminished.
But it's great that yours hatched and I hope at least a couple of them are still around doing their thing.


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## Sdaji (Nov 19, 2018)

Flaviemys purvisi said:


> Fair enough mate, I've spent very little time in Melbourne. It must have been a very cool summer though for the eggs to have spent substantial time below 22°. Heh heh #bungalowlife Despite my scepticism, Without having all the exact data of the daily temps and just as importantly, the humidity levels your "shelf eggs" were exposed to, it's difficult to argue with you.
> 
> I certainly wouldn't attempt to incubate longicollis eggs at 22° or below, the success rate would be substantially diminished.
> But it's great that yours hatched and I hope at least a couple of them are still around doing their thing.



Even during the hottest months of the year, Melbourne routinely has nights well below 20 degrees, and this bungalow was near the top of a hill (Box Hill actually), on the south aspect of the hill, so the cold extremes were much cooler than the reported 'Melbourne' figures. Incubation lasted more than just the hottest part of summer anyway.

I doubt you'd get many to hatch if they spent most (say, more than 50%) of their time below 20 degrees, but mine certainly spent a significant amount of time that cool.

Haha, funny you should say 'Bungalow life'. That sums up that period of my life pretty well! Not especially pleasant but in a funny way I look back at it with fond memories. Maybe because it was a big turning point. Then again, with so little stability, every stage of my life seems to be a turning point! Haha!


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## Mick666 (Nov 23, 2018)

I lost most of my jungle clutch last year due to a heat wave (I'm assuming that was the cause). The next clutch went in the air con and I got 24 from 24. i'm doing the same this year.


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## Neil j (Nov 23, 2018)

2016 my caramel zeb jag clutch I set at 32 climbed to 35 late on and they started hatching day 49. What surprised me there was no veins left in the eggs just a dry empty shell. All hatched.
[doublepost=1542939750,1542939650][/doublepost]Heat wave due here Monday mick 40c


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## Yellowtail (Nov 26, 2018)

This clutch of Julattens just hatching now about 2 days earlier than expected confirms the pattern.


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## LilithLeChat (Nov 26, 2018)

Yellowtail said:


> This clutch of Julattens just hatching now about 2 days earlier than expected confirms the pattern.
> View attachment 325661



YAY!!!


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## MANNING (Nov 26, 2018)

Yellowtail said:


> This clutch of Julattens.......
> View attachment 325661



YES PLEASE YELLOWTAIL!


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## Yellowtail (Dec 13, 2018)

Just to destroy the theory high temps can shorten incubation period this lot that were in early stages when I had the high temps have hatched right on time.



[doublepost=1544653382,1544516158][/doublepost]


Yellowtail said:


> Just to destroy the theory high temps can shorten incubation period this lot that were in early stages when I had the high temps have hatched right on time.


One thing was unusual when they all came out. 13 albinos and only 4 hets?

Could the heat event early in their incubation cause this? My limited knowledge of genetics says no and the same pair last year with no heat spikes during incubation resulted in 9 albinos and 6 hets which was unusual but this is extreme.

Expert opinions please?


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## Sdaji (Dec 13, 2018)

No. Temperatures can not change the ratio of albinos. The genetic code of the embryos is determined at conception which occurs before the eggs are laid.

Also, it's very much a fact that eggs incubate faster at higher temperatures. Brief spikes may have differing effects at different periods of incubation, but as long as the temperatures remain within a range at which development can occur, development will be faster at higher temperatures. Eggs at a later stage of development may be able to accelerate development at higher temperatures more effectively than eggs at an earlier stage of development, which would explain why the last clutch of yours appeared unaffected. If you choose a fixed temperature for the entire duration of incubation you will see it very clearly.


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