Reptile & Amphibian Forums

I by no means consider myself to be a prolific breeder of graybands, but have paired up our wild caught alternas from the 90's and 2000's to produce perhaps 10 to 15 clutches of 7-13 eggs each. In all other years leading up to 2010, our eggs have incubated for 60-62 days. Amazingly, the clutches from this year pipped just yesterday, 102 days since being laid! The only variable I tweaked this year was the average temperature, which I kept ast 75, as opposed to 80-82 in prior years. Now comes the question for all of you more experienced alterna fanciers out there: is a 5 degree gradient enough to postpone pipping by 40 days? That seems quite stange to me, but it may be true. Does percentage water content in the vermiculite pose a possible cause for this phenomenon as well? Any thoughts would be appreciated.

Marlon

102 days! That's a long time.

I too decided to tweak the temps a bit this year and go for some longer incubation times. I cooked my stuff at between 78 and 80 for both thayeri and alterna. My stuff was pipping at 72 to 76 days. At 80-82 I get them cracking more like 60-65 days. It's amazing what a few degrees will do.

Did you happened to take note of the overall health of your hatchlings for such a long incubation time? I've hears some people say that longer incubation times will give you are larger, healthier baby. I've seen that with my stuff this year to some degree, but I think that the more important variable is what you are feeding mom.
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Brad Alexander

FullSpectrumHerps.com

Thanks for the reply, Brad.

Yes, the hatchlings are very robust and a bit larger than I've seen hatch out before. Also, the eggs seemed to grow larger than I've seen them before. Maybe if larger neonates are desired you could incubate them at lower temps. I'm wondering if there would be a higher male or female yield with lower temps?

Marlon

>>Thanks for the reply, Brad.
>>
>>Yes, the hatchlings are very robust and a bit larger than I've seen hatch out before. Also, the eggs seemed to grow larger than I've seen them before. Maybe if larger neonates are desired you could incubate them at lower temps. I'm wondering if there would be a higher male or female yield with lower temps?
>>
>>Marlon

No, you will not see different gender ratios from temperature. Snakes have a ZZ / ZW genetic system for that so gender is determined at fertilization. Here is a quote:

"The ZZ:ZW system is also found in all snake species."

This ZZ / ZW system as opposed to mammals XX / XY system something they have shared with birds for millions of years. The reason it is different from mammals is that in snakes and birds the homogametic ZZ is male as opposed the heterogametic XY in mammals.

This temperature dependent systems is something from turtles and crocodilians... not all reptiles and not any snakes.
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___________________________
Herp Conservation Unlimited

If people really learn from their mistakes, I should be like the smartest guy in the world

I have been incubating my eggs at approximately 70 °F to 78 °F...so far NONE have hatched (the eggs are still good)...the first clutch was laid on June 29th...so we are coming up on three months...

As far as the sex determination idea....doesn't work in snakes as Lance pointed out. In fact my clutch of Gray Rat Snakes incubated at the above temps hatched at a ration of 13:4!

I'll let you know the health of the baby alterna once they hatch....

By the way, anyone want a male Gray Rat Snake neonate CHEAP!
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G. Merker

Bob Hansen had something strange happen this year. He had one clutch go a long long time, but strangely it was with or next to other clutches that hatched in a normal amount of time (under same conditions). Check with him for details, it was something I had never heard of.