How Do Chameleons Hatch Naturally?

[ReptiGeek]

Last night I was having a hard time falling asleep, and of course my brain started to think about things I need not think of. But then an interesting thought crossed my mind. How do chameleons hatch naturally? Now I know this might seem like a silly question, but I am curious to know if anyone knows the success rate of hatchlings that are able to breach the earth's surface when they are up to 12" deep in compact soil. Another thought was, when a female deposits the eggs, they are basically stuck together in a clump. If the eggs are to stay in a clump for an incubation time of 5-9 months in the wild, would the centre eggs be cut off from optimal growth, humidity from the soil, and oxygen?
Now, I know the success rate of the hatchlings actually surviving to adulthood is likely only 0-5% of the entire clutch, so that is not what I was wondering about. Just curious to know how many may actually hatch and how they manage to claw their way to open air being so small and fragile.

 

[ReptiGeek]

Awe, nobody? C'mon you chameleon brainiacs!

 

[fluxlizard]

I don't have all the answers for you but I can give you a few things for thought.

Firstly- Years ago I knew someone who studied lizard egg incubation at the local university. She thought it was hilarious that I worried about ventilating my eggs. At the time I was poking pinholes in my containers so there was a tiny amount of gas exchange, and then weighing the containers and adding water to bring the evaporated water weight back up. Meanwhile she was using sealed jars to incubate eggs under different gas conditions (more CO2, less CO2, whatever). When she found out about my pinholes, she started laughing and asked me how much fresh air eggs get buried underground. There is a little gas exchange in decent soil, but really, it isn't much. I've been using sealed food storage containers and keeping them sealed ever since. So, the eggs in the middle- I'm really not amazed. The eggs are like putting a bunch of marbles in a jar- there is still some air in there around them- even the middle ones, and there is space from middle all the way to the outer edges.

As for digging out- I think conditions are not "hard packed earth". Females tend to select sights around tree roots and presumably select sites with sandy well draining, loose soil, etc. rather than clay or something that would pack in tight. I kind of wonder if wild nests go so deep anyway- females will dig in captivity pretty deep- but mine usually seem to stop when they hit a non-easily dug area- whether that is all the way to the bottom of a 5 gallon garbage can or part way down a pot only several inches deep. Probably when digging in around treeroots it doesn't take long to hit a root or a big rock or something and go ahead and make the chamber. If digging conditions are not as easy as a bucket of sand or loose earth, maybe they wouldn't go as deep either. Babies tend to hatch all at the same time in nature- not over a couple of weeks as in captivity. So the big digout is a community effort with all the siblings.

Mortality rate is usually counted for animals that actually make it out of the nest I think, not the number of eggs laid.

The whole thing is really amazing. Life in general is I think.

Interesting questions you are asking.