Captive tortoise breeding is important as it benefits the wild populations in so many ways. For instance, captive breeding programs have helped recover diminished wild populations of many different threatened species such as the Galápagos tortoise species.
Of course, captive-bred tortoises are also necessary for the pet trade. It is essential that tortoise enthusiasts only acquire captive-bred chelonians and never wild tortoises as captive-bred chelonians don’t negatively affect the wild populations.
To feed the ever-growing demand for pet tortoises, successful breeding programs are needed. In this article, we will look at how to breed tortoises as well as the basic requirements.
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Suitable tortoise mates
Before you can breed chelonians, you need suitable mates. For two tortoises to be compatible for mating, they need to be of the opposite sex, they need to be of the same species and the same subspecies (when applicable), and both need to be of age. The easiest way to tell if a turtle is sexually mature is by measuring the shell.
Here are some adult sizes of some popular tortoise species usually bred.
- Adult female – 13 kilograms (28 lb)
- Adult male – 20 kilograms (44 lbs)
- Length: 15 to 36 cm (6 to 14 inches)
- Learn more about the desert tortoise
Sulcata tortoise / African spurred tortoise (Centrochelys sulcata)
- Adult female – 70 to 90 lbs (31 to 40 kg)
- Adult male – slightly bigger
- Length: 24 to 30 inches (61 to 76 cm)
- Learn more about the African Spurred tortoise
American Redfoot tortoise (Chelonoidis carbonarius)
- Length: 30 to 40 cm (12 to 16 inches)
- Learn more about the red-foot tortoise
Hermann’s tortoise (Testudo hermanni)
- Weight: 2 to 2.5 kg (4.41 to 5.51 lb)
- Length: 12 to 23 cm (4.72 to 9.06 inches)
- Learn more about the hermann’s tortoise
Leopard tortoise (Stigmochelys pardalis)
- Weight: 15 to 54 kg, avg. of 18 kg
- Length: 30 to 70 cm, avg. of 45 cm
- Learn more about the leopard tortoise
Yellow Footed Tortoise (Chelonoidis denticulatus)
- Length: average of 40 cm (15.75 in)
- Learn more about the yellow foot tortoise
Russian tortoise (Agrionemys horsfieldii)
- Adult female – 15 to 25 cm (6 to 10 inches)
- Adult male – 13 to 20 cm (5 to 8 inches)
- Learn more about the Russian tortoise
Egyptian tortoise (Testudo kleinmanni)
- Adult female – 10 to 12 cm (4 to 5 inches)
- Adult male – 8 to 10 cm (3 to 4 inches)
- Learn more about the Egyptian tortoise
Marginated tortoise (Testudo marginata)
- Length: 30 to 38 cm (12 to 15 inches)
- Learn more about the marginated tortoise
Also, the partners need to be disease-free and healthy (that is, the turtle must have no deformities that can affect its ability to mate or lay eggs).
Many experienced breeders advocate that you quarantine the turtles for about a year before allowing them to breed if you haven’t had them for long.
During this time, you should have the turtles checked for diseases and other health conditions.
Since chelonians are long-lived and can be fertile long into their lifespan, even elderly chelonians can breed. However, it is best to select younger females for breeding.
Elderly females are less fertile compared to young females. Also, the breeding process is quite strenuous and is a task which elder females struggle with.
Courtship and mating between males and females usually occur after hibernation/brumation, but this can occur at any time when the tortoises aren’t hibernating.
If you want tortoises to mate, the best you can do is provide a comfortable large enclosure where both the male and female can be kept together. (Refer to the care sheet of the tortoise species you want to breed and take note of their care and enclosure requirements.)
Courtship starts when the male shows aggressive mating behaviors. While courtship can go on for a long time the actual mating is quite short. The tortoises may mate several times.
I recommend having both the male and female together for a few hours a day, a few days a week. This should offer more than enough time for fertilization but at the same time reduce incidences of injuries.
To summarize, here are the things to consider before allowing a male and female tortoise to breed.
- The chelonians need to be of the same species and the same subspecies when applicable.
- The female should not be gravid. That is to say, she must have laid all her previous eggs.
- The female should be of adult length but still young.
- The chelonians need to be healthy and free of any health complications.
How to tell if the tortoise is gravid
The tortoise is gravid when she is carrying eggs. If you plan on breeding the tortoises then it is quite easy to see the changes in behavior as you would have an eye on that.
Female tortoises can retain sperms for several months and even years. So a female can lay fertilized eggs even if she hasn’t mated in a long time. Here are some signs to watch out for.
- Restlessness – Gravid tortoises are restless. They can’t seem to stay in one place. They may always be on the move, climbing, and even digging.
- Digging around the enclosure – When the tortoise digs, it’s usually in an attempt to create a nesting site. If the tortoise digs with the hind legs then she is most likely gravid.
- Change in appetite – A gravid tortoise may start off eating a lot more than they usually do. However, this doesn’t last. Expect the tortoise to eat much less. This loss of appetite is down to two reasons. Firstly, the female spends more time trying to find a suitable site to lay her eggs. Also, the eggs take up a lot of space and constrict the stomach.
If you want to be 100% certain, you should have a vet x-ray the female. This should reveal the presence of any problems the female may have and the number of eggs.
This refers to the inability to lay eggs. Egg retention is very harmful and even leads to death.
Egg retention is usually down to a lack of a proper nesting site. Stressful living conditions and pre-existing conditions can also cause dystocia. To prevent this, ensure nesting conditions are optimal.
Creating Optimal Nesting Conditions
Temperature, humidity, and sunlight are all important for successful nesting. This can be a challenge if the tortoise isn’t endemic to your locality. You need to ensure that temperatures within the enclosure are right and that the tortoise has an adequate nesting site.
The soil in the nesting area should be soft and slightly moist with a few rocks and logs so the female feels safe about hiding the eggs here.
The substrate of the nesting area needs to be deep (about 12 to 20 inches deep) and several feet in diameter.
An outdoor pen or greenhouse is best. Create this nesting area inside the tortoise’s pen.
The nesting substrate should compose of 60 percent topsoil and 40 percent sand such as Mosser Lee Desert Sand Soil Cover. Hoffman Sphagnum Peat Moss is an excellent topsoil substitute.
The temperature of the soil in the nesting site should be around 86 °F (30 °C). Place a heat lamp (incandescent bulb) to obtain this temperature range.
Indoor Nesting Site
If you don’t have a lot of space or a greenhouse, you can encourage nesting within a box. The box should be large enough to snugly fit the tortoise. It should be filled with about 12 inches of substrate.
Again, the ratio should be 60 percent topsoil and 40 percent sand. Similarly, the substrate should be lightly moistened.
Place the female into the box which should be in a dark room with a single light source that should hang directly over the box.
Place the tortoise in the box for at most an hour before returning her to her enclosure.
This ensures that the tortoise doesn’t overheat or becomes dehydrated.
In this case, a herp vet forces the female to lay her eggs by injecting her with oxytocin (a hormone).
After the injection, the female tortoise should lay the eggs within a few hours. The vet will first x-ray the tortoise before the injection.
Successfully incubating reptile eggs require you to get three things correct, these are temperature, humidity, and lack of disturbance.
While there may be small variations from one species to another, the discussed conditions in this article should be optimal for incubating any tortoise egg.
As with other reptiles, agitating the egg or turning it upside down can lead to the death of the developing hatchling. Incubation usually takes about 100 days.
To ensure you dont turn them upside down you can make an x on the egg shell using a marker to know that it is facing the same direction.
Eggs can hatch as early as just 50 days. The higher the incubation temperature, the faster the eggs will hatch.
Once the hatchlings start emerging from the egg, do not help them. Let them break their way through by themselves. Only help if the tortoise is in serious trouble.
Some hatchlings can break free within minutes, while it takes others days, even weeks, to break free. Most breeders place the newly hatched turtles into very shallow lukewarm baths which clean away sticky membrane and allow the hatchling to have a drink.
Some excellent incubators for hatching tortoise eggs include Hova-Bator, Zoo Med’s ReptiBator, and Juragon.
Good substrate maintains a good moisture level. I recommend asbestos-free vermiculite. Coco coir, peat moss, a mix of topsoil and sand, and peat moss all work well.
Keeping a constant temperature within the correct range is essential for successful incubation. I recommend a temperature between 77 °F (25 °C) and 95 °F (35 °C).
Keeping a constant temperature within the mid-80s is advisable. Keep a constant temperature as fluctuating temperatures lead to malformation and even death.
You want the hatchling to develop at a stable rate. With turtles, sex determination is based on temperature.
For Mediterranean tortoises such as Greek tortoise, Hermann tortoise, and Egyptian tortoise, at 86 °F (30 °F), the sex determination is 50:50. Below that, the hatchling is more likely to be male.
And above that, the hatchling is more likely to be female.
Humidity levels are crucial as you don’t want the egg to dry out. Even in the wild Mediterranean tortoises lay their eggs below ground where moisture levels are optimum.
Ensure that the relative humidity of the incubator is between 50 and 90 percent. It isn’t essential to keep a constant humidity level. Just make sure the humidity levels are between 50 and 90 percent.
A humidity level of 70-75% is best in my opinion as there is little chance that the humidity level will accidentally fall before 50 percent and rise above 90 percent.
Keeping the eggs still
Too much disturbance within the first few days of development can lead to the egg dying. When you pick up the egg, make sure you don’t turn it upside down.
Also, don’t shake the egg as this will definitely kill the developing hatchling. Pick up the eggs gently and place them in the incubator which should remain undisturbed until the eggs hatch.
Tortoise breeding is a rewarding and enjoyable process. With the growing demand for pet tortoises, this activity is also a profitable one. In addition to this, breeding helps protect wild populations.
Captive breeding in the tortoise’s endemic geographical range is always best, as it is much easier to incubate eggs under the tortoise’s native habitat’s conditions.
However, there are times when this is not possible. For instance, the demand for pet sulcata tortoises is very high in the United States, although this species is endemic to the southern edge of the Sahara desert.
In the case where you are breeding the sulcata turtle in a temperate zone, you need to provide the optimum conditions needed.
If you have any additional questions or information, leave a comment.