Reptile & Amphibian Forums

I am a pro at ball pythons and got the wife involved in bearded dragons. Had a clutch laid today and need the Ideal Temps to incubate them...there were so many different incubation temps I found. I set them up the same way as the ball eggs and put them in the same incubator that I have eggs for the balls cooking now.. I have another one warming up for the dragons as soon as the Ideal Temp is verified.
Thanks all
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RIVERSIDE REPTILE BREEDERS

When my dragons lay their eggs... I separate the klutch of eggs into 2 groups. 1 for females and 1 for males. My Male incubator is set at 83-85.5 degrees. My female incubator is set at 80.5-83 degrees Farenheight.

For example: Out of a klutch of 20 eggs. 10 eggs go in each incubator and maybe 1 out of the 10 eggs will turn out to be the opposite (expected) sex/gender.... So my theory works pretty well.

Make sure the incubator is in a regualted room temperature as well (the room temp. should not fluctuate).

Best of Luck!
www.AtlantaBeardedDragons.com

In general,82-86 are preferred temps. The eggs can withstand cold periods [ if it was winter and your 'bator malfunctioned and temps. went down to 60's or 70's for a day or so] better than over-heating.Atlanta dragons ,some day I'll have to try that method of yours.

Thanks Angie... It works well when you are breeding high end stuff (Trans, leathers, hypos, etc.) because you can control the sexing I WANT ALL FEMALES so its not a bad way to predict how many holdbacks I will have for next years breeding. All of my females cost's are higher anyways. Its a trick of the trade.
www.AtlantaBeardedDragons.com

Strange. Everything I've ever read and heard says Beardies sex is determined genetically. So if you you really are experiencing TDSD then you have genetic males showing female tendencies and vice versa. If this were true there would be issues in the next generation.

Yes I have read that this is not true for BDs either the temp dept sex gradient issue.

I have read that using cooler temperatures say 82 instead of 85 allows the dragons to develop just a little slower in the egg and therefore they end up being healthier dragons.

Here is a question:

I've always wondered how silkbacks come out of the egg. Doesnt the eggtooth get messed up along with the other scales and hard outer covering?

The dragons at the cooler temp are taking a little longer to develop arent they?

Do they seem to be any healthier?

Bearded eggs are super easy to incubate compared to other reptiles.

I have seen many clutches of eggs fluctuate indoors from 75 degrees at night to close to 90 degrees during the day and all of them hatched perfectly.

Also, I have had eggs hatch underground and babies emerge, in our southern california soil. Most of these eggs fluctuate between 68-75 degrees in about 12 inches of soil, and take about 4-5 months to hatch. I have had females lay close to the surface where the eggs are exposed to even greater temp extremes and they also hatched.

Many people keep their bearded eggs around 84-86 degrees. Normally, they will hatch in about 2 months when kept at these temps. I keep some of mine like this, and most in my gecko room where the temps range from 78-84 degrees. I still get the same ratios of males/females incubated both ways

Josh

I think it is genetic too. There is one cross i did this year that has produced 3 clutches of all males. The eggs were incubated with the others that produced pretty equal ratios males/females. Josh

aerg.canberra.edu.au/reprints/2004_Sarre_Georges_Quinn.pdf

Nice article on the topic.

You may have to download it if you want to read the article.

In the article... it is a challenging read unless you are scientifically inclined. I am to a certain extent.

Paraphrased from for the article:

Basically the argument is this...

the current line of thinking is the two types of sex determination types are thought to be mutually exclusive unto themselves.

Like you either have to have TSD (temp *environmental* sex determining) reptiles.

Or...

You have genetic sex determining found in a certain type of reptile.

The article argues that these two things are not mutually exclusive.

The genetic type of sex determining is thought to be the older form of the two.

But in some reptiles the TempSD has begun to really play more of a noticeable effect when studied.

However the article argues that there are other factors at play...

The males testosterone and how the androstetidone is transferred and estrogen synthesis etc etc. Gonad factors come to play into the equation. Male testosterone levels in other words factor in.

But as I was saying they are not thought to be mutually exclusive. You actually have TSD and GSD (temp % gene sex determining) factors at play simultaneously.

Males are found the extreme typically:

lots of warms or lots of colds

more males

Intermediate temps more females.

So this is counter to what some claim as either just hot: more females or cold more males

Intermediate temps: more females

Extreme temps: more males

The article states that TSD and GSD are closely related in reptiles. And some/most have incorporated both albeit with a few exceptions where one type of determining factor presides over the other.

See here from the article:

More recent work by Shine provides the strongest evidence yet that TSD and GSD may coexist in reptiles. They incubated eggs from the montane and chromosomally heteromorphic three-lined skink, Bassiana duperreyi, under temperature regimes that mimicked natural temperature variation. When temperatures were similar to those in the field at high altitudes in cool summers, sex ratios were significantly skewed. Approximately 70% of eggs produced males, a result that could not be explained by differential mortality. This suggests that, at the lower extremes of the natural range of temperatures experienced during incubation, sex in this species is temperature sensitive resulting in temperature
over-riding the underlying genotypic sex that prevails at other temperatures.

Read the article you will see. I would say that BDs are both TSD and GSD. Maybe a bit more toward the GSD side but the temp does play a minor factor to a small extent as it does with most other reptiles also.

Alligators and sea turtles have more specific TSD or GSD tendencies.

"all of them hatched perfectly."

Sorry, this is a pretty bold statement. The results were the same as incubator hatched eggs.

Leopard geckos are a prime example of TSD. Higher temps not only produce a majority of males, but also geckos with less black pigment.

Pretty cool stuff.

Josh

Many reptiles are Temperature sex determined, but not all of them. I don't think bearded dragons are but I haven't done much personal research in this particular area. As sex ratios are not 50/50 in most clutches, very difficult to tell if a higher temp produced more of one sex than the other, without a long term study.
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PHLdyPayne