Sex and temperature of egg incubation


New Member
As I knew from books and TV, the sex of some reptiles is determined by the temperature of egg incubation. Is it also applicable to Chameleon, especially Ri. Brev (I specify it just because i am keeping them now)?

Thank you.:D
dont know about that to be honest but I asked the same thing and I think that there was some people speculating that some species if not all could be temp induced.

What I gather is that no one has precisely controlled the incubation temps within a 2 degree temp for the whole incubation period so you could plausibly say that yes it can be controlled.

I tried to figure this out with snakes a while back but couldnt spend the time and the money to be accurate with it.
Here's some sure that the conclusion that because one species of chameleon is GSD that all species must be....
"I conclude that the veiled chameleon has genetic sex determination (GSD) and that anecdotal accounts of temperature-dependent sex determination (TSD) for this species, and other chameleons are likely to reflect reporting or statistical bias."
"the study suggests that the sex of Chameleo calyptratus is not governed by incubation temperature, but most likely fixed at conception by genetic factors."
O.. thank you for your replies. It seems sex of chameleons, at least of some species, is determined by genetic factors. I have four little pymgy babies now. I incubated them at 25C +/- 1C with an eletronic temperature-controlled incubator. Let see whether all four little guys become same sex. Report to you guys later on. :D
Even though you incubated the eggs at a set temperature, if the sex is all female you will still have to test the theory further to prove that it wasn't just a coincidence. If you want to show the range of temperatures that produces each sex even further investigation will be needed. It would still be interesting to find out though!

When eggs of known TSD reptiles are incubated there are ranges for each sex...a certain range of a few degrees in temperature will yield all males while a different range of a few degrees (higher or lower, depending on the species) will yield all females. When you hit the middle temperature range usually there is a mixture of males and females...and often they are not good reproducers.

For instance for (alligators) A. mississippiensis where the sex depends on the temperature of egg incubation...temperatures 30°C or a few degrees less produces all females, 34°C up to a few degrees hotter yields all males.

In some species there is a second "window" of temperatures where the sex can switch back to the opposite sex of the temperature range just above it. In some turtles, for instance, a certain range of high temperatures produces females and range of low temperatures produces males...but if you incubated the eggs at even lower temperatures it would switch back to yielding all females.

With some species there can also be a certain time within the incubation that the temperature is important in the determination of the sex, from what I have read.

Certainly an interesting topic!
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