If the eggs are small and discolored (or discolor quickly after laying) they may be infertile. If the shells themselve are soft or disformed, most likely your rankin's female is not getting enough calcium and vitamin d3 to process it. Check all your husbandry setup, including basking temperature, change your UVB bulb (if more than 6 months old). An hour of unfiltered sunlight a day at least 6 times a week, will do more for your dragon than any UVB light out there on 14 hours a day every day.
If the basking is too low, not enough calcium being included in food (either as dusted insects, or greens themselve, good calcium rich greens are collard greens, mustard greens, dandelion greens, endive, escaroli, etc.) Or if she is getting to many calcium binding agents in with his diet, this could be preventing her from absorbing the calcium she does eat. Spinach is very bad for this, Kale has alot of phosperous which can prevent calcium absorption etc. For more info on what kinds of greens and veggies to feed bearded dragons, see the following webpage:
www.beautifuldragons.com
Another option you can do is take the female to a reptile vet and have him do blood work and x-rays to check for bone density and blood calcium levels. If these are low, then you know your problem stems from something missing or wrong with her husbandry (and this is easily fixed). Keep in mind that egg shelling drains calcium reserved alot.
If all the calcium levels are fine with your dragon, then it may be a problem with the male rankins. If you have other female rankins with the same problem, that have mated with the same male, then it would deffinitely be him. He could have a low sperm count or if housed separately, may be best to put him in with the female(s) again to get him to mate with them more often before separating again. If this is the only female having the problem or is the only one you have, try her with another male rankins for next season and see if that makes any changes. (if you do have another male that is).
Age of the female could be playing a factor as well. If she is still too young, she may not have the necessary resources to support multi clutches of eggs, hence the bad eggs and high infertility rate. She should have been at least 15 months old before breeding, to give her time to reach full size and maturity. If she is over 6 years, she is leaving her reproductive prime, and really nothing you can do to improve her clutch laying. It would be best to completely retire her from breeding.
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PHLdyPayne
