Variable incubation temperatures

[Neal]

One of the topics at the TTPG conference today was about turtle egg incubation. I am assuming that temperatures affect tortoise eggs the same they do turtle eggs.

The point that was brought up is that turtle eggs that are incubated with variable temperatures versus a constant temperature produce turtles that are more active, stronger, and basically healthier than those produced at a constant temperature. I have never heard of this before, I had always thought nest temperatures remained constant, and if you chose to artificially incubate you should keep the eggs at a constant temperature.

I was interested in hearing if anyone on here incubates their eggs with variable temperatures and what have you noticed related to activity level etc… between variable temperature incubated tortoises and constant temperature incubated tortoises.

 

[egyptiandan]

These are temperatures in the nest of a Hermanns tortoise in Bulgaria. Nest temperatures are always variable in the wild. Though in the tropics the variation will be much smaller. In the study they found that less hatchlings hatched in the wild nest as opposed to in an incubator with a constant temperature. So it's better for the embryos to have a more constant temperature, but with a variable temperature you weed out hatchlings that probably wouldn't survive in the wild. So I can see where a variable temperature would make for stronger hatchlings as they have already made it through a weeding out process and are the ones with the best attributes to handle wild variables. Temperatures below are in celcius.


Hour-----June---July---August---September
6:00-----22.6---21.6---22.9------17.4
15:00----33.6---32.1---34.8------25.3
22:00----26.5---26.0---27.1------19.8

Danny

 

[ALDABRAMAN]

Interesting, we incubate at 86 degrees and have always gotten great results.

 

[Neal]

The speaker also indicated that this improved hatch rates. He was talking about turtles specifically though, so I don't know how much applies to tortoises.

 

[gummybearpoop]

A friend of mine hatches out an incredible amount of tortoises every year and he lets the temperatures naturally fluctuate. He says the tortoises tend to be healthier as well.

Did you enjoy the conference Neal? There were some very good presentations. I missed the last few on thursday.

 

[Neal]

Ya the conference was cool, even the turtle talks had a lot of good information. I missed all but the last 4 talks on Thursday so maybe that's why I didn't see you there. Did you catch this talk about turtle egg incubation?

 

[Tom]

Interesting, we incubate at 86 degrees and have always gotten great results.

ALDABRAMAN, Which species and what sex ratios do you typically get t a constant 86?

To everyone reading: We got some great info at this conference and a lot of the innovation seems to be learned by chance or by "mistake". Anyone with an interest in breeding, turtles or torts should really make this conference a priority. The author of just about every turtle and tortoise book I own was there and I got to pick their brains.

 

[armandoarturo]

:O! Tell us more about it!

 

[Neal]

:O! Tell us more about it!

They recorded the conference and told us they were going to make a DVD available at some point. Check the website www.ttpg.org, I'll post on the forum when it becomes available.

 

[ALDABRAMAN]

Interesting, we incubate at 86 degrees and have always gotten great results.

Aldabra tortoises. We have no clue as far as the ratio of male/female. I keep in touch with one of our local customers that has two from the same clutch from ten years ago and his are a pair. Big size and growth differences.

 

[onarock]

I incubate my eggs in a broken but new stand up freezer. I have always targeted 85-86. I never worried about the incubator getting as low as 83 and as high as 88 even though that rarely happends.