box turtle eggs

Question
I have a box turtle that I bought about 3 months ago. She had been kept in a tank with several other box turtles in her previous home. She laid an egg today and then ate it. I didn't discover the egg until it was already just a shell. Is this normal? And could this egg have been a viable egg? What should I do if she lays another?

Answer
Hi Patrick, The egg certainly could have been fertile. Box turtles can store sperm from a earlier breeding for a period of a few years so even eggs she produces over the next few years may be fertile!! They can produce more then one clutch per year and a clutch can be around  2 to 5  eggs.  
Females will instinctively bury their eggs and a container with several inches of damp sand or sandy soil (something that holds a tunnel shape) should be provided for her. A fellow keeper who has Florida box turtles has had a similar egg-eating experience with his pair when he was surprised by the timing of the egg and had not provided a laying chamber for the female. Box turtles certainly would eat the eggs of other species that they may come across. It may also reflect a bit of calcium deficiency with your female. Egg production puts great demands on the body's calcium stores. Box turtles will consume pieces of cuttlebone ( a calcium source sold for pet birds) which can just be  placed in the enclosure. You can also scrape cuttlebone over her food. In a pinch even a broken up TUMs antacid can be used.

These are some links that will help you if you choose to incubate any other eggs she might produce. The key thing when you find them is to not rotate them. Reptile eggs must stay in the same upright position that they were layed.

This first link will help you make an artificial incubator using an old aquarium (or any container that holds water) and an aquarium heater.

http://www.iguanasalad.com/archives/4

These links will help you set up the eggs for incubation.

http://aboxturtle.com/box_turtle_incubation.htm

http://www.tortoise.org/general/eggcare.html