In the course of my work, I am often contacted by turtle owners whose pets cease feeding and become unusually restless. The behavior appears suddenly, sometimes after many uneventful years – a Common Musk Turtle did so after 22 years in my collection – and seems to have no external cause. A normally placid turtle may begin frantically paddling or wandering about, trying to climb the sides of the terrarium and escape. Food, once the focus of the creature’s existence, is ignored.
It surprises some folks to learn that turtle and tortoise eggs may develop even if the female has never mated, and that mated animals may retain sperm and produce fertile eggs years later. Unfortunately, gravid (egg-bearing) turtles can be very choosy when it comes to nesting sites…a ½ acre exhibit failed to satisfy some I’ve cared for at the Bronx Zoo! If the eggs are not deposited, blockages due to over-calcification and life-threatening infections invariably result. Fortunately, there are ways to “convince” your pet to lay her eggs; failing this, several effective veterinary options are available.
What To Do
If your female turtle or tortoise suddenly stops feeding and begins to act as described above, first check that something has not gone wrong in the environment. Overheating, Lysol poured into the tank by a mischievous child (actual story), or cage-mate aggression can all cause similar behaviors.
If you suspect eggs, your best option would be to have radiographs done by a veterinarian (please post below if you need help in locating an experienced vet). Your vet can determine how many eggs are present, approximately how far along they are in their development, and if problems related to unusual size or over-calcification can be expected. Also, other health issues that may cause similar symptoms can be investigated.
Creating a Nest Site
If you have some experience and suitable space, you may wish to set up a nesting area before bringing your turtle to a veterinarian. Be aware, however, that the nest site must be ideal if it is to be accepted. The species’ natural history is the main factor to consider, but there is also a great deal of individual variation as well. For example, I once participated in a study of Green Sea Turtles (Costa Rica) wherein it was documented that certain individuals always choose shady sites and others sunny, while some seemed to have no preference.
Warm, moist areas are attractive to many species, while others prefer to deposit eggs within a cave or near plant cover. Use reptile night bulbs to heat nest sites, as the black/red light they emit will not disturb turtles after dark, when many species deposit their eggs. Please see the linked articles for further information on creating nest sites, and be sure to post your questions below.
When unable to find a suitable nesting site, some turtles deposit their eggs on the substrate, in water, or wherever possible (the eggs of many can endure some time under water, so be sure to incubate any you discover).
However, the unsuccessful search for a site generally causes them to retain the eggs far longer than would be normal. Calcium is continually added to the retained eggs, causing them to increase in size – sometimes to the point where they cannot be passed naturally. These eggs eventually decay, leading to egg yolk peritonitis. If untreated, this infection is fatal.
Prompt veterinary attention should be sought if your turtle is unable to deposit her eggs. A (human) labor-inducing medication known as Oxytocin is usually quite effective when administered to gravid turtles. In extreme cases, surgery may be called for. Please post below if you need a reference to a local veterinarian experienced in turtle care.
While the eggs of Common Snapping Turtles and other consummate survivors will often do well at room temperatures (in a hot room, in summer), a reptile egg incubator will greatly simplify the hatching process. Please post your incubation questions and observations below once you’ve obtained a clutch.