Possible egg infertility

[jobeanator]

Hello-
I have questions I am hoping some keepers that have had similar experiences I have encountered. I currently have a 3.8 group of redfoots that I acquired 2 years ago. The first year with the group, I had many signs of breeding but no eggs or anything. The last year till present breeding has been consistent and daily, and I have received 5-6 clutches from many different females. Every clutch I have artificially incubated. The temperatures I have incubated the eggs are at a consistent 86-87 degrees. Humidity stays also around 80-90%. Eggs are kept in incubation for a max of 160 days and still no results. I have also candled after a couple of weeks and see no chalking or any signs an embryo is evident. I will say I have pulled a recent clutch on 12/19/21 and looks like I possibly see some chalking in some eggs. Also, I use hatch rite for the medium for incubation. I know many breeders that use this and also vermiculite. My question is why are there so many infertile eggs? Could it be the diet? Could it be the hatching medium? Could it be some of my males are shooting blanks? ( this one personally I don't believe is the issue). I would love to hear feedback on this or help in any way possible. I would love to pick a breeder's brain with any experience they've had with this or know what the issue might be.
-Joby

P.S- I have attached photos of my incubator and current eggs.
P.P.S- It has been a long time since I have posted in here and its good to be back!

 

[Maro2Bear]

Good luck. One would think that it can’t be the substrate or diet. But ill defer to some of the experts. @Markw84

 

[Markw84]

Too much to address at once, but a few things:

It could be diet, but lower on the list of suspected causes. Be sure the adults are getting a good diet with lots of the vitamins and minerals. (calcium and D3/sunlight) especially for the females)

Are the adults related?

What temperatures and overnight lows are the females subjected to while forming the eggs?

I would definitely not use perlite. Although probably not an issue in regards to fertility, it is a very real potential problem if new hatchlings ingest some. I use vermiculite, and personally I believe in mixing in 1/2 peat moss to decrease the pH of the medium. (helps with calcium chelation and then uptake by embryo)

I always use a covered container for the eggs. A few small 1/4" holes in the sides, but covered. Otherwise they will desiccate way to easily. Female tortoises release quite a bit of water into the nest chamber when they dig and lay. That nest chamber is pretty close to 100% humidity.

 

[Tim Carlisle]

Too much to address at once, but a few things:

It could be diet, but lower on the list of suspected causes. Be sure the adults are getting a good diet with lots of the vitamins and minerals. (calcium and D3/sunlight) especially for the females)

Are the adults related?

What temperatures and overnight lows are the females subjected to while forming the eggs?

I would definitely not use perlite. Although probably not an issue in regards to fertility, it is a very real potential problem if new hatchlings ingest some. I use vermiculite, and personally I believe in mixing in 1/2 peat moss to decrease the pH of the medium. (helps with calcium chelation and then uptake by embryo)

I always use a covered container for the eggs. A few small 1/4" holes in the sides, but covered. Otherwise they will desiccate way to easily. Female tortoises release quite a bit of water into the nest chamber when they dig and lay. That nest chamber is pretty close to 100% humidity.

I have no intention of ever breeding tortoises, but this was educational! lol

 

[jobeanator]

Too much to address at once, but a few things:

It could be diet, but lower on the list of suspected causes. Be sure the adults are getting a good diet with lots of the vitamins and minerals. (calcium and D3/sunlight) especially for the females)

Are the adults related?

What temperatures and overnight lows are the females subjected to while forming the eggs?

I would definitely not use perlite. Although probably not an issue in regards to fertility, it is a very real potential problem if new hatchlings ingest some. I use vermiculite, and personally I believe in mixing in 1/2 peat moss to decrease the pH of the medium. (helps with calcium chelation and then uptake by embryo)

I always use a covered container for the eggs. A few small 1/4" holes in the sides, but covered. Otherwise they will desiccate way to easily. Female tortoises release quite a bit of water into the nest chamber when they dig and lay. That nest chamber is pretty close to 100% humidity.

The tortoises are not related, as they were all imports years and years ago. As I stated in my first post these eggs were laid on 12/19/21. Do you think it's too late to cover the eggs now?

 

[cooky_luvs]

Since you didn’t get eggs last year it sounds like these are their first clutches. Unfortunately the first clutches are often, but not always infertile. My first year of eggs I got 6, all infertile. Last year there were 9, only one fertile. This year i’m at 37 eggs and 4 have hatched so far and some more look good with visible embryos. The last clutch was 5 eggs and only 2 developed and one died in development. Fertility will improve over time.

 

[jobeanator]

Since you didn’t get eggs last year it sounds like these are their first clutches. Unfortunately the first clutches are often, but not always infertile. My first year of eggs I got 6, all infertile. Last year there were 9, only one fertile. This year i’m at 37 eggs and 4 have hatched so far and some more look good with visible embryos. The last clutch was 5 eggs and only 2 developed and one died in development. Fertility will improve over time.

Congrats!
I'm hoping that could be my issue- as I have experienced this before with other species also. My group has laid multiple clutches with no fertile eggs. Usually, spring/summer time breeding ramps up, and i should get many clutches. I hope you have continued success!
-joby