8 replies to this topic

[SueW]

A friend has an experienced breeder who typically lays 2-3 nice clutches each year. In the last 5 years, her incubated eggs have resulted in only two viable eggs/hatchlings. Her clutches are 5-8 eggs each. Putting aside questions of male fertility and proper incubation, has any read or heard of causes for female infertility? My friend read once about samonella causing infertility in birds, but he can find no other such references. Anyone heard of anything along this line? (Female is 30+ yrs old, LTWC - long-term wild caught).

Edited by SueW, 22 January 2012 - 02:52 PM.

[turtlemann2]

hmm interesting indeed. this turt does she normally hibernate? i know that hibernation has a major impact on the viability of eggs, and production of healthy sperm in males. other then this i couldnt think of any other reason and i also did a little looking around and couldnt find anything stating an effect caused by salmanilla. although im impressed that she lays 2-3 clutchs with such high number of eggs, does he only have success hatching 2 eggs of every clutch or ever?

[SueW]

He has gotten nothing from the last 3-4 batches of eggs. "Alice" semi-hibernates -- in cold basement and quite inactive, but not fully down. This has been her life for 20+ years. In 2010, she yolked up eggs in June but did not lay them all summer. She was in her usual habitat outdoors with appropriate areas. On the advice of a rep vet, I fostered her up and active through last winter. She returned to her home in May and laid her year+ old eggs on July 5. None developed. On July 28, she dug a nest and laid 7 eggs. None viable. Thanks for reply.

[turtlemann2]

hmm this is quite parculure (sp*) the ONLY thing i can suggest is attempting afull hibernation perhaps the refridgeration technique? also how do you know she yolked up? simply by feeling her cavity or x ray?

[SueW]

The eggs were seen by the vet on fluouroscope.

[BoxTurtleLover]

In my experience the issue is probably her age.  As females age, they can start to produce thinner shelled eggs and also deformed eggs.  They can also be prone to becoming eggbound.  A wildlife rehabber I know once told me of an older female boxie who started to lay eggs that looked like Hershey Kisses.  Now I am assuming this may be the problem as I do not know the age of the turtle, but over 30 years for a female boxie is at the top of a normal lifespan in captivity so it's really hard to say.  While hibernation does play a critical role in the fertility cycle I have had non-hibernating females lay fertile clutches the following June of 4 or more fertile eggs.

I would suggest either retiring her from breeding and keep her away from males or give her a break from breeding for a while and see what happens.

[SueW]

Thanks for the reply. I have read of researches finding 60 yo boxies gravid in the wild. Have not heard of life-span change in captivity.

[BoxTurtleLover]

SueW, on 24 January 2012 - 12:21 PM, said:

Thanks for the reply. I have read of researches finding 60 yo boxies gravid in the wild. Have not heard of life-span change in captivity.

I've seen and read varying things also.  Unfortunately, captivity alters the wild environment unless one owns several acres of woods and keeps turtles there without any human interaction and it's hard to say how old any turtle is unless one knows when it hatched.  I reread your postings - is this female mating on a regular basis with one single male or are there other males?  A female in the wild can usually retain male sperm for about five years.  If she is not mating frequently, that could be another reason for infertile eggs.  If she is still healthy, fed well and kept properly she could still lay eggs for many years but box turtle females do age and there can be problems associated with that aging as with any aging animal.

[SueW]

"Alice" has two suitors and she has been seen to breed with each of them.