Incubating Eggs

[Yvonne G]

I've been thinking about the way we all place our tortoise eggs in the containers in the incubator. We line them up, side by side. When mama tortoise poops them out into the hole she dug, they fall on top of and next to each other. So I've been toying with the idea of piling eggs up in a pile next time I incubate them. I have a nice, deep Zoo Med Reptibator that would allow a deeper container of a 'pile' of eggs. Any ideas on this subject?

 

[G-stars]

I wonder if different temperatures are achieved this way as well, resulting in a mixture of males and females. Will the eggs toward the bottom be cooler than the eggs toward the top?

From a survival point of view, it wouldn't make sense for all of the hatchlings to come out one gender. Anyone have further thoughts on this?

 

[Markw84]

There have been lots of studies on this, especially with sea turtles and snapping turtles. Definitely found a difference in sex ratios top to bottom of nest. With larger tortoise with larger egg chambers, this certainly would come into play. Of course choice of nest site also has a great deal to do with sex ratios as some females seem more prone to lay in more open locations, while others prefer closer to some bush cover.

I think the egg pile is an interesting technique to try. I would think it would also trigger more mass emergence as one moving and hatching would cause its neighbor to feel the activity. I also think there is value to so much of the egg to be open to air, as the only contact with round eggs is a very small area of contact with the neighboring egg. We all seem to spend time "buring" eggs at least partially, while a female tortoise spends a great deal of attention to making the inside of the egg chamber as smooth as possible, and then plugging the top with a mud plug to keep the eggs as uncovered as possible!

My biggest block in doing this so far has been the extreme differences we see in pipping times with eggs artificially incubated. How does an emerging tortoise keep from damaging the yolk sac of a neighbor?

 

[wellington]

I just wonder Mark, if with the piling, and possible waking the neighbor egg to wake, if that would take care of the egg sack from being damaged, they are all trying to hatch at/about the same time in a tight fit hole there isn't much room to crawl out until the top ones have moved on out?

 

[wellington]

I wonder if different temperatures are achieved this way as well, resulting in a mixture of males and females. Will the eggs toward the bottom be cooler than the eggs toward the top?

From a survival point of view, it wouldn't make sense for all of the hatchlings to come out one gender. Anyone have further thoughts on this?

I wonder if with trying this method, if the hole should be as closely duplicated to the natural hole the female would have dug?

 

[wellington]

I've been thinking about the way we all place our tortoise eggs in the containers in the incubator. We line them up, side by side. When mama tortoise poops them out into the hole she dug, they fall on top of and next to each other. So I've been toying with the idea of piling eggs up in a pile next time I incubate them. I have a nice, deep Zoo Med Reptibator that would allow a deeper container of a 'pile' of eggs. Any ideas on this subject?

I did always wonder why we lay them flat and apart from each other. It will be very interesting to see how this goes. Would be nice if you could do this with a window that goes the whole length of the hole so you could watch what they do in this pile up from bottom to top.

 

[Markw84]

I did always wonder why we lay them flat and apart from each other. It will be very interesting to see how this goes. Would be nice if you could do this with a window that goes the whole length of the hole so you could watch what they do in this pile up from bottom to top.

Seems like a clear Tupperware bowl would do the trick. But then... Does total darkness have something to do with simultaneous emergence?

 

[wellington]

Seems like a clear Tupperware bowl would do the trick. But then... Does total darkness have something to do with simultaneous emergence?

Hmmm, might have to do a dark curtain, removable black paper or something?

 

[Markw84]

I can't help but think that all the looking, the light, the adding water as they might dry... All the things we do with artificial incubation, prompts hatching earlier than they would in a totally dark, undisturbed nest. I would bet the hatchlings stay in their eggs quite a bit longer in a natural nest, absorbing the yolk sac and waiting for probably rain to increase moisture in the chamber, maybe lower oxygen levels in the egg, and trigger emergence. A tortoise hatching in an incubator may be breaking out of the egg a few weeks earlier than it would have if left totally dark and undisturbed. That way all the clutchmates would "catch up" to the early developers, and all are ready to hatch and emerge at the same time????????

 

[Yvonne G]

I tried a bunch of Manouria eggs that way year before last. I was pretty sure they weren't good because I found them in the nest pile late and the decomposing litter got the eggs pretty hot, but I put some leaf litter in a 5 gallon bucket, then piled in the eggs, then loosely added more leaf litter. I set the bucket in one of my winter time covered enclosures and set up black lights to get the interior temperature up to where I wanted it. A thermometer probe told me what temp the egg grouping was, and it was staying stable at about 85F. I occasionally added a bit of water to the bucket. None of the eggs were any good, and so none of them hatched. But next batch of leopard eggs I get I'm going to try the pile method.

I have two batches of SA leopard eggs sitting at room temperature. I want to try my hand at actually hatching them before I try any experimentation. I'll experiment with the babcock eggs when I get the next batch.

 

[Markw84]

I tried a bunch of Manouria eggs that way year before last. I was pretty sure they weren't good because I found them in the nest pile late and the decomposing litter got the eggs pretty hot, but I put some leaf litter in a 5 gallon bucket, then piled in the eggs, then loosely added more leaf litter. I set the bucket in one of my winter time covered enclosures and set up black lights to get the interior temperature up to where I wanted it. A thermometer probe told me what temp the egg grouping was, and it was staying stable at about 85F. I occasionally added a bit of water to the bucket. None of the eggs were any good, and so none of them hatched. But next batch of leopard eggs I get I'm going to try the pile method.

I have two batches of SA leopard eggs sitting at room temperature. I want to try my hand at actually hatching them before I try any experimentation. I'll experiment with the babcock eggs when I get the next batch.

I eagerly will await your updates when you do that.

I agree - tough to experiment with our precious eggs!