One of the most common and serious problems faced by turtle keepers involves female turtles (mated or unmated) that develop eggs but refuse to deposit them in the terrariums or aquariums in which they live. While this can be the result of any number of health problems (i.e. low calcium levels, tumors), the lack of an appropriate nesting site is more often than not the cause.
Retained Eggs
It’s very difficult to keep turtles, especially semi-aquatic and aquatic species, in an enclosure that allows for year-round access to a nesting site. Providing a terrestrial nesting site, as well as adequate swimming space, usually involves the use of a pool or pond as opposed to an aquarium.
Gravid females without access to a nesting site usually become very restless and may deposit their eggs in the water. This is not, however, a safe strategy, as such females wait for a long time before expelling their eggs, and may not deposit the entire clutch. Retained eggs may become over-calcified and difficult to pass, or they may break within the female’s body and cause an infection (egg yolk peritonitis) that is invariably fatal if not treated early-on.
Nesting Preferences
In order to provide your turtles with acceptable nesting sites, it is essential that you are familiar with both the species’ natural history and the individual turtle. In this way, you will be able to provide the site at the correct time of year and manipulate other factors (i.e. temperature) appropriately.
The substrate and location of the site provided is also important – a soil/sand mix is acceptable to many turtles, but some (Batagur baska, most softshells) prefer sand while others (Black-Breasted Leaf Turtles, Geoemyda spengleri) often choose to lay alongside a log or other structure. During my Bronx Zoo years, I spoke with several colleagues (at different zoos) who observed gravid Giant Musk Turtles (Staurotypus triporcatus) to consistently choose elevated nesting sites.
Further Reading
Please see this article on Snapping Turtle Reproduction for further information on the breeding habits of this most prolific turtle.
Video of a Snapping Turtle digging a nest and laying eggs.
Snapping turtle laying eggs image referenced from wikipedia and originally posted by Moondigger
Thank you so much for your information! We have 2 RES-one male and one female. We have a large outdoor pond with surrounding nesting area that is fenced and safe. Unfortunately, Sunshine seems to want to lay eggs now. We live in Oklahoma and have crazy weather so we usually wait until May or June to move the turtles back outside to their outdoor habitat. In the late fall we move them inside to a 60 gal aquarium and we have a sunning platform with a light. We have made a nesting area out of a tub, but I’m concerned it isn’t large enough. Would it be better to go ahead and move her outside-temps may be 80 one day and 40 the next, make a nesting area out of a kiddie pool outside and move her in and out depending on the temp, or keep trying the tub? We will also see if we can find a vet that treats turtles here. Our guinea pig vet may, so we’ll check with her. Any advice is appreciated!
Jennifer
Hi jennifer,
Thanks for the kind words.
They often lay out of season….influence of captive light cycles and other factors. A kiddie pool sounds like best option…plenty of space etc. I would not leave outdoors permanently yet, easy to contract a respiratory infection after sudden period of low temps.
The link below lists 2 turtle experienced vets in OK; ask for a reference from them if neither is close. Your regular vet may be able to administer oxytosin if turtle does not deposit eggs, procedure is well known, straight forward. Please keep me posted, frank
http://www.nytts.org/nytts/helpnet.htm#OK
Hi Frank, first off, thank you for the great articles you have posted as they have helped me the most in my search to learn more on gravid turtles. I have a single 14 year old map turtle of some kind that as far as I know has never been exposed to other turtles (based on info from the previous owners). I’ve owned her for five years and I just found three eggs inside the tank, all broken. I’m completely new to this aspect of turtles so am not sure what is a normal amount of eggs for them to lay, but I’m also concerned about making a nesting area because she is so shy and adverse to being held, moved, etc. I also am unsure what type of nest she’d be most inclined to. Any insight you can provide on this would be fantastic. Thanks again!