Some thoughts about eggs and incubation temps

[acpart]

Now that my season is over and the results are in, I wanted to post some of my thoughts and theories about incubation and temperature fluctuations. This season, for the first time, I used a commercially purchased mini-fridge, in my case the repti-pro5000. I also used the SIM with a thermostat probe inside the SIM and the digital thermometer in the incubator. As I posted in another thread, I had trouble keeping the incubator at the correct temperature when the ambient temperature changed greatly (it seems that the "heat" element and the "cool" element are designed separately and don't kick in when you'd expect). My previous 5 seasons were with hobovator and a digital thermostat. I would have to put the hobovator in the basement for most of the summer since the ambient temps in my house would exceed my incubation temps, and, as you know, you can't cool the hobovator (this is why I went with the minifridge).

Here are my stats for this season:

AFT's: 5 healthy hatches, hatch rate of 50% (some eggs laid in the dry hide; 50% is similar to my hatch rate last season with the hobovator)

Leopard geckos: 37 hatches, 85% hatch rate (not counting eggs laid by a female gravid when I got her, probably by an immature male, who laid infertile clutches until I bred her to one of my males), also similar to my hatch rate with the hobovator last season.

Of these 37:

33 healthy with no problems
2 (clutchmates) had eyelid deformities
1 was born small, did not thrive or eat and died after 3 weeks
1 is possibly a dwarf: eyes are small, but not deformed, weighs 8 grams at 2 months but is not proportioned like a newborn

I generally incubate at 81 or so. There were times during the season when the ambient temps were changing dramatically (I live in New England and have no AC). In those cases, during the course of a few days, the temperatures could get as low as 78.8 or as high as 83.2. The clutchmates with the eye deformities were born 6/28, about a month after my first leo hatchlings, and I don't recall there being any dramatic temp fluctuations around that time.

Here's my point: I do think we should be as diligent as we can to minimize temp fluctuations. I wonder, though, if one issue with temp fluctuations causing deformities is due to the speed of the temp change rather than the absolute temp change. With the minifridge, the temps did change rather slowly. As you can see from above, I had a nearly 5 degree temp change from min to max but it was usually a 2 degree difference or so from my ideal temp (on some occasions the temp got 2 degrees or so lower and on other occasions the temp got 2 degrees or so higher). My experience has made me think that slow temp fluctuations, even of several degrees, is not cause for panic.

This is not hard scientific evidence, but more like anecdotal evidence. I'd be curious about what others have found and what they think about this.

Aliza

 

[acpart]

So, just out of curiousity, is no one really interested in this topic? Or, is the post off-putting because it's so long? Or perhaps was I so complete and correct that no one has anything else to say (ha ha)?

Aliza

 

[fl_orchidslave]

My results were similar, I just haven't run any reports yet. With first year breeders there were some infertiles but things picked up toward the end. Plus I changed to superhatch after trying perlite and sphagnum. Oh, and moving in the middle of it all Aliza, I think a lot of people think it's easy to breed and make money selling animals. Seems like every other 10 year old at the shows wants to breed. Looking at actual results of the whole operation, including cost, could change that. We had a number of rehabs at the beginning of the season that took some focus from thinking of breeding. Thank goodness they are all in permanent homes now, except my little Apple Annie. She's staying with me There are only 2 sub-adults left in quarantine, that I may or may not keep. One is a sweet little enigma super snow, I wanted to learn about them firsthand. If I have to take one for our herp society I will, temporarily, but no more rehabs for a while. One adult died, six had to be euthanized vs one baby died, one culled. It's taken a lot just in the past year and I need a break from it, to have some fun and enjoy my animals a bit more With what I already had, a few holdbacks, a few picked up, next year will hopefully bring more smiles

THanks for posting your results

 

[softballstud_1099]

Aliza, I am with you on the temp change. I don't think that 2 degrees will make that big of a deal. I think that a baby with diformities will have these no mater what. You know I have read threads on here that the temp is kept at a certain degree for like weeks and then slowly bumbed up. would this not cause diformities? If not then I don't think a couple of degrees will hurt anything. I hope I made sense......lol

 

[Gregg M]

Temperature has a lot to do with the health of hatchlings...

In the wild eggs are not exposed to outside temperature fluctuations... Even just 6 inches underground, temperatures will only fluctuate 2 degrees throughout the entire hatching season... In composting material there is almost no fluctuation...

There are ways you can check this (I have done it)... One way is to just get a thermometer with a probe that records high and low... Put the probe 6 to 8 inches under the ground (the depth at which most reptiles deposite eggs) and record temps... You will see that there is almost no change from day to night and sunny days and cloudy days... Even when one day is 5 to 10 degrees cooler there is almost no change at all 6 to 8 inches underground...

I believe that temperature stability is very important during incubation and any sharp spike in temp, no matter how slight, can affect development to a degree depending on what stage of development the spike happens at...

I dont think it is as simple as "small temp spikes are ok and large temp spikes are bad"... The development of an embryo during incubation is much more complicated... Even variations in oxygen absorbtion, carbondioxide absorbsion can affect development and they can be influenced by temperature as well...

Aliza,
I honestly think you are incubating too low on the spectrum for the incubator you are using... I think your fluctuations would be less if you incubated around 85 degrees... That is a good middle ground and you will still get more females than males if that is what you are aiming for with your lower incubation temps...

 

[Keith N]

We had some power company long outages twice during our season. I noticed the temp and humidity rise. We did have a few deformities that came from eggs that were in there less than 2 weeks before each outage. Older eggs were not affected. So when the second power blip happened I was pretty bummed about it because I could then reference the eggs to see which ones were now in jeopardy. It was an interesting experiance, not one I want to do again but interesting.

 

[acpart]

Thanks for the information Gregg. I didn't mean to imply that big temp changes are bad and small ones are OK, rather that obsessing about a 1/2 degree temp change may not be necessary. Given small fluctuations within 2 degrees or so, I wonder whether it makes any difference if these fluctuations happen rapidly or slowly. My extrapolations from my season suggest thqat there may be a difference.

I'm intrigued by your suggestion that I incubate at 85. I've been reluctant to go that high because I don't want even 1/3 males. I have raised my target temp for the past 2 seasons from 80 to 81.5 and gotten 1 male per season at that temp. Maybe I'd be willing to go up to 83. Did you mean that the low end of the spectrum is not good for "the type of incubator [I'm] using" because of the temp fluctuations?

Aliza

 

[Kristi23]

Inside the SIMS, my temps were 83/84 all season. I ended up with way more males than females. I hate going lower, but I think I may have to.

One positive thing is that I only had a couple deformities all season. Last season had a lot more with the same incubator. I'm thinking I have the SIMS to thank for that. Thanks Gregg!