Why Is My Crested Gecko Laying Eggs Without A Male?

Have you ever encountered eggs in a crested gecko tank only inhabited by female geckos? 

Could it be possible for a female crestie to lay eggs without mating—no contact with males involved? 

Whether you’re just curious or you checked on your lone female pet recently only to discover she’s now in the company of some crested gecko eggs, it’s a question worth asking.

Let’s get started on the answer.

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Why Is My Crested Gecko Laying Eggs Without A Male?

Yes! A female crestie can indeed lay eggs without males involved. If there’s truly been no contact with a male gecko, though, these surprises will be infertile crested gecko eggs since mating needs to occur for an egg to be fertilized.

While normally we think of animals as needing both a male and female to produce something like an egg, female geckos can actually do this all on their own.

It’s not different than humans, though, actually, if you think about it—human women also release a mature egg from their ovaries every month during ovulation, but it doesn’t necessarily become an embryo. 

It takes fertilization from male sperm for this to happen.

The same thing goes for this gecko species, except in this case, you’ll find outward evidence of such an egg.

Fun fact: Chickens and other egg-laying species also lay infertile eggs!

How Often Can This Happen?

How often are you going to stumble across eggs in your crestie’s tank?

Female crested geckos usually start laying eggs (with or without a male) around 18-24 months of age or when they weigh about 35-40 grams. 

They can start as early as one year old and 25-35 grams, though.

Female healthy adult geckos will lay eggs every 30-45 days, usually in a clutch of two eggs.

This can happen year-round, though, after 7-9 clutches, there’s typically a dormant period of 10-12 weeks before the process starts up again.

Note the timing and frequency of these occurrences can vary quite a bit between individual geckos, though.

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Crested Gecko Infertile Eggs (Vs. Fertile Eggs)

If your female crestie is laying eggs without a male and has not been in a situation where mating could have occurred, her eggs will be infertile (also known as slug eggs). 

This means they won’t produce an embryo—so don’t worry, no crested gecko hatchlings in your future!

But how can you be sure it’s an infertile clutch? 

What if your female had been exposed to a male before you acquired her? 

Female geckos can actually retain sperm for up to a year, so if she underwent breeding during this time before you adopted her, there’s a chance the eggs she’s laying are indeed fertile, and you could be getting another surprise come hatching time.

So how can you tell the difference between infertile and fertile eggs? 

Hold the egg to a light source, like a focused penlight flashlight, while the rest of the room is dim. 

Hold the egg in front of the light and look for a red ring in the top third or quarter of the egg.

If the egg doesn’t have any red spots, veins, or rings and is yellow all the way through, it’s probably not fertile. 

To double-check, though, let the eggs undergo a few weeks of incubation and then look again. 

Sometimes it takes a bit of time for these red markers of fertility to develop. 

Where Will My Crested Gecko Lay Her Eggs?

Whether or not the eggs are fertile, it’s good to know some more about the process, starting with where the egg production will take place. 

Wild geckos will look for hidden spots to lay their eggs (like under bark, rocks, logs), so it’s good to provide your female crestie with an equivalent spot in the form of a nesting box like this one.

A nesting box should size up at around 10″ inches (25 cm) long, 5″ inches (12.7 cm) wide, and 5″ inches (12.7 cm) tall, filled with a moist substrate like sphagnum moss. 

Make your own from a plastic container—be sure there’s an entrance hole in the lid for your gecko to enter.

Otherwise, she will turn to dig up the substrate in the tank, laying her eggs within and covering up the spot. 

Egg-laying can take about 45-60 minutes, and you should give your gecko some space alone in the tank during this time. 

What Do I Do With The Eggs?

Once the eggs are laid, you’ll want to be sure to remove them from the tank within 24 hours, so they don’t dehydrate and place them in an incubation box. 

Be sure to handle the eggs gently and remove them one at a time, avoiding any rotation along the way. 

Moving the eggs can kill the embryo (if there is one developing inside). 

Use a marker to (gently) mark the top side of the eggs before moving them, so you know which way is up.

Your incubator might be a commercial incubator like this one or create your own using a lidded plastic container. 

Fill it with an incubation medium like vermiculite, which should be moistened, but not so much it drips water. 

Make sure to create a few small holes in the lid of your container to allow for air exchange. 

Apart from these holes, you should be dealing with an airtight egg container.

If there’s even a slight chance of fertility (or, indeed, if you’ve been gecko breeding on purpose and hoping for fertile eggs), you’ll definitely want to transfer the eggs to an incubator and give your gecko eggs a fair chance to hatch.

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Crested Gecko Incubation Conditions

Incubation temperature and humidity do matter in the egg incubation process. Incubation time will also be affected by these temperatures.

Your reptile egg incubator should be between 68-80° degrees Fahrenheit (27° C), with 70-72° degrees Fahrenheit (22° C) being the sweet spot. 

Note: At higher temperatures, the incubation period will be shorter. 

At lower temperatures, the incubation period will be longer (up to 100 days or more). 

The average incubation time, at average temperatures, is usually 60-70 days.

Optimal humidity in the incubation box should be 85-90%. 

Because temperature range and proper humidity are important considerations, a commercial incubator regulates these incubation conditions for you could be a smarter, more convenient option than making your own cheaper incubator (though it’s still possible!).

If you make your own, be sure to check incubation temperature and humidity regularly with a thermometer and hygrometer, respectively.

Monitoring The Progress: Crested Gecko Eggs to Hatchlings

Part of crested gecko care extends to the eggs which may appear in their tank, whether it’s a purposefully mixed or all-female terrarium. 

During the lengthy incubation period, there are a few things you’ll want to look out for.

Check on your container with eggs often, like every day, and keep notes of any changes in the eggs. 

Eggs from an infertile clutch often won’t last more than 3 weeks and will become moldy, yellow, or dried out looking after a short period of incubation.

Fertile eggs, on the other hand, will be white and solid. 

But sometimes, even damaged-looking eggs can turn out to be fertile, so be patient before you throw away or flush any potential crested gecko hatchlings! 

There’s no substitute for experience when it comes to making these distinctions.

After the 60-70 day mark, if incubation conditions have been ideal and the eggs fertile, it might be time for a gecko egg hatching. 

When a hatchling gecko is ready to enter the world, it will slit the eggshell, though it may take 12-24 hours to emerge fully. 

Do not remove babies until they are fully out, as they will be taking this time to feed off what’s left of their yolk sacs. 

Once the babies are fully exposed, be ready to transfer them to a small, separate terrarium like this one

Line the bottom with paper towels and use a cap for food and water, noting your hatchling gecko will prefer water droplets, so also be sure to mist the terrarium twice a day.

Final Thoughts

At the start of all this, we asked the question of whether or not female crested geckos could lay eggs without mating. 

The answer, amazingly, was yes—even without prior breeding of crested geckos, egg production may occur in an all-female terrarium.

So no worries if you find crested gecko eggs in your female-only tank—this kind of clutch production is likely to yield infertile eggs, meaning no beautiful baby cresties will be springing from the shells.

For a gravid gecko (meaning pregnant) to lay fertile eggs, she would need to have been fertilized by a male—possible only through prior contact.

If you are, in fact, interested in raising some gorgeous gecko babies, we recommend researching gecko breeding requirements to get the lowdown first. 

Cresties are a gecko species known for being productive breeders, but there’s a lot you’ll want to learn first about the particular care for breeders required.