The reasons are many, but, first and foremost is, our(keepers) cages suck. That is, they are not suitable for the requirements to hatch eggs(or even keep monitors)
Our cages and our setups and our choice of animals are not often not very good. We have seen with good pairs, that both parents envolve themselves with the whole process of recruitment. That is, they not only mate, but the male helps with nesting, and limited protection of nests. I get the feeling, they may even help the hatchlings escape the nests.(that is only my opinion) Many ground nesters nest very deep and there is little chance of babie ackies or storrs, digging up thru two feet of rockhard ground. Also, these is one paper where the authors dug down an ackie burrow and found babies in the burrow and hatched eggs and more babies in the chamber at the end. Now if you really think about that, How did a burrow large enough to be called an ackie burrow lead to the eggs. Wouldn't it be from the eggs to the outside? and wouldn't it be very tiny, the size for hatchlings. Which would not be recognized as an ackie burrow. There are billions of tiny holes in the desert. Also, the paper talked about following the burrow. My experience is when hatchlings dig out, they dig strait up.
Also, eggs take long periods of time and our cages do not stay in the proper temp and humidity range for those periods.
With that said, if the timing is right, we can hatch eggs in cages, I have done that with both caudos and ackies.
Its also, my experience that most of the nesting material people use, kills eggs. That is, if the eggs are not removed, quickly, then they die. That should indeed tell you, how bad your nesting medium is.
And lastly, because we do not enclude the required tools for monitors to go about their daily lifes, they often destory the cages(dig up everything) in search of their needs.
When conditions are good, they will not only avoid the eggs, but seem to understand exactly where they are and make sure they are not disturbed. Even to a point that when several clutches are laid, they do not disturb the exsisting eggs.
Lastly, the state of our knowledge is really low. Most people do not even understand the basics, they do not know how to sex monitors, nest monitors, even keep monitors(pairs, groups, etc) Some boneheads still think they are solitary and have no social life or behaviors. I hope some of this helps, FR
