How To Tell If Your Crested Gecko Is A Boy Or A Girl

Crested Geckos (Correlophus ciliatus) make fantastic pets. They’re docile, easy to care for, and always smiling. But if you have just brought home your new Crested Gecko, how do you find out whether it’s a boy or a girl? 

Mature male Crested Geckos have pronounced hemipenal bulges below the vent. Females are flat in this area. Male Crested Geckos also have a row of scales with tiny pores just above the vent. You can locate these with a magnifying tool or quality camera. Females lack these pores. 

Those are the key points for sexing (telling apart boy and girl) Crested Geckos. Sometimes it is a little more complex than this, though! Read on to discover common mistakes people make when sexing Crested Geckos and find out whether girls or boys make better pets. 

How To Identify The Gender Of A Young Crested Gecko

Hatchling Crested Geckos are impossible to sex. This is because as babies they don’t have any features with which to tell boys and girls apart. 

Once they reach around 5 grams in weight at approximately 4 months old, you may be able to identify preanal pores above the vent of the males. At this stage, experienced Crested Gecko keepers are able to sex the gecko with reasonable certainty. However, it is not until the gecko is fully grown that it becomes easy to tell the males from the females. 

Preanal Pores

Preanal pores are pretty difficult to see but can help you identify whether your Crested Gecko is male or female before reaching sexual maturity.

You will need a magnifying tool such as a jeweler’s loupe, a strong magnifying glass, or a macro photography setting on a decent camera. Even a good smartphone camera can work well.

Look at the lower belly of your Crested Gecko, just above the vent (butt). You are looking for a thin line of scales that look a little different from the others, stretching across the belly in a thin line from inner-thigh to inner-thigh. 

Take a photo and zoom in, or look closely with the magnifying tool. If the center of the scales have tiny dark dots or indentations, these are pores.

The pores are only found on males. They are for secreting pheromones to attract females for mating, as well as to mark territory. 

Femoral Pores

Femoral pores are just like preanal pores, only they are in a different place. Using the same technique, look for a line of scales with tiny pores in their centers running down the inner thigh of your Crested Gecko. If you find them, you probably have a male gecko.

Can Females Have Pores?

Yes, females can sometimes have something like pores too. They are fake pores or pseudo-pores. However, the pseudo-pores of the female are much smaller than the males’ pores.

Given that you will already need a lot of magnification to see the males’ pores, you can probably guess that the females’ are essentially invisible! 

Also, the pores of the females are likely to be random or sporadically placed. The males’ pores, on the other hand, will be arranged in clear lines as described above.

You may also notice some liquid secretions from the males’ pores that you will not see from the females’. The secretions contain the pheromones. 

How To Identify The Gender Of An Adult Crested Gecko

Crested Geckos reach sexual maturity at around 9 months old. They should be more than 16 grams in weight by then. At this time, you will be able to see the bulge of the hemipenes beginning to drop down.

The gecko and the hemipenal bulge will continue to grow for several months. 

Hemipenal Bulge

The hemipenal bulge is found just below the vent on the male Crested Gecko. It is partially separated, defined into separate bulges, similar to the testes of a human male. However, despite sometimes being referred to as “gecko balls”, the bulge does not house testes at all. 

Hemipenes are structures used for passing sperm to the female during mating and reproduction. Squamates, including lizards and snakes, have hemipenes. Usually, these are stored away, folded inside the male’s body. 

When it is time to mate, they are expressed on the outside of the body using erectile tissue. Hemipenes do not look elongated like mammalian penises, but rather like lumpy mounds of flesh. 

Male Crested Geckos have very obvious bulges that cover the hemipenes, unlike some other squamates. These start to develop at around 6 months old and continue to grow up to 1 year of age.

The bulges can be seen from the side, below, and often even from above. This makes sexing adult Crested Geckos pretty easy!

Can Female Crested Geckos Have Hemipenal Bulges?

Female crested geckos can’t have hemipenal bulges as females do not have hemipenes. Most females will have a slender, flat area in the place where the males have the bulge. However, some females will have bulges of fat in the same area. This is especially true if the female is a bit overweight.

When trying to sex your Crested Gecko, this can be super confusing!

The key is to look for the partial separation between the two sides of the bulge and consider how prominent the bulge is. Males’ bulges are very obvious!

Also, you can assess some of the other factors described in this article, and build up evidence to conclude whether your gecko is a boy or a girl. 

Misleading Methods Of Sexing Crested Geckos

Sexual Behavior

Once your Crested Geckos become sexually active, you will have another way to judge their gender. During mating, males need to be on top, and females need to be underneath.

You can check whether they are the top or bottom gecko to help you figure out what gender they are. 

There can be some false starts and confusion when it comes to mating. Seeing one gecko on top of another is not enough to conclude that one is female and the other male.

However, if you observe them in the same positions frequently, you should be able to work out which is which.  

Cloacal Spur Size – Can Female Crested Geckos Have Spurs?

No matter if male or female, all Crested Geckos have cloacal spurs. These look like two white pointy horns that poke out from the side of the base of the tail. You can find them in the same area that you look for the hemipenal bulge. In many cases, males have larger cloacal spurs than females.

However, this can very often be misleading. Females can have large cloacal spurs too.

For this reason, you cannot sex your Crested Gecko using the size of their spurs alone. However, you could take this into account while trying to work out whether your pet is a boy or a girl. 

Head Size

Males tend to have larger, wider heads than females. However, this isn’t always true and could cause confusion! 

As with cloacal spurs, it is best not to use head size to judge whether your Crested Gecko is a he or a she. Instead, consider head size along with the other factors listed above. 

Size Difference Between Males And Females

The overall size of male and female Crested Geckos is not a good way to tell them apart! Some Crested gecko enthusiasts say that males are larger, and some say females are larger. In general, the weight and size of the Crested Gecko can vary between individuals. 

Here is a guide as to how much a healthy Crested Gecko should weigh as they grow. Note that you can begin sexing them at around 4 months, and sex them with greater certainty around 9 months old. 

Age of Crested Gecko	Approximate Healthy Weight
Hatchling 0-2 months	1.5-2 grams
Baby Juvenile 2 months	3 grams
Baby Juvenile 3 months	4 grams
Baby Juvenile 4 months	5 grams
Baby Juvenile 5 months	7 grams
Juvenile 6-9 months	9-17 grams
Juvenile 9-12 months	16-30 grams
Sub-adult 12-18 months	30-50 grams
Mature-adult 18+ months	35-55 grams65+ grams = obese

How To Handle A Crested Gecko To Check Its Gender

It is important to always be gentle and patient when handling your Crested Gecko. Approach and reach into the enclosure where they can see you. Gently smooth the gecko, then wrap your fingers underneath and gently lift the gecko out. 

Crested Geckos cannot regrow their tail once they drop it. For this reason, and to be a considerate owner, it is important to hold them by the body only. Grip them firmly but gently. 

In order to check the lower belly of your Crested Gecko to sex them, it is a really good idea to get help from a friend.

One of you should gently hold the gecko up, or tip him so he is in a slightly vertical position. The other person can check the gecko over or take close-up photos. 

Another really useful idea is to inspect the belly of your Crested Gecko without removing it from the enclosure. Simply take photos or inspect its belly using a loupe through the glass of the vivarium, when the gecko crawls up against it. 

Why Find Out Whether Your Gecko Is A Boy Or A Girl?

It is really important to find out whether your gecko is a boy or a girl because they have different needs, so knowing this is essential to their care.

Furthermore, male and female geckos can’t always be kept together, and neither can male geckos be kept together. If you don’t know which one you have, you may end up with injured pets or a lot of babies! 

Of course, you may simply want to know whether to refer to your pet as a ‘he’ or a ‘she’! Plus, it helps to know the gender when picking out the all-important name.

Your Crested Gecko is going to be with you for a long time, so it is definitely worth checking to find out the gender of your pet. 

What Other Differences Exist Between Male And Female Crested Geckos?

Social Behaviour

Female Crested Geckos can be housed together happily in the same enclosure. Males, on the other hand, will fight and cannot be housed together after they are sexually mature. 

A single male can live with a group of females but could show aggressive behavior. A single male should not be kept with a single female because he is likely to pursue her all the time and will probably end up injuring her or at least causing chronic stress.

In all cases, the more space that can be provided to the group, the fewer social issues are likely to arise. 

Health Problems

Male Crested Geckos often face health issues related to prolapse of the hemipenes. This means that instead of being able to withdraw the hemipenis back into the body, it gets stuck on the outside. 

In the early stages, you may be able to assist by applying gentle pressure to it to encourage it to go back inside. However, if the hemipenes get stuck out for too long, they are likely to dry out and get infected. 

Female Crested Geckos also face health problems of a different kind. Female Crested Geckos will lay eggs, even if there is no male present to fertilize them. Sometimes, the eggs can become stuck inside the female’s body. This problem is called egg binding. 

If egg binding occurs, it may need to be treated with surgery. This can be costly, as well as traumatic for the female. In addition, you will also need to be mindful of the female’s egg-laying cycle and provide sufficient calcium in her diet. 

Life Span

Crested Geckos can live for a really long time. On average, they will live for 15 to 20 years, but possibly could reach the grand old age of 30! Males tend to live longer than females. However, this is not guaranteed. 

Do Male Or Female Geckos Make Better Pets?

Which gender is better really depends on how you want to keep your Crested Geckos. As we learned above, if you want multiple geckos that can live happily together, you will need all females. You can also have one male, but only if you want to breed baby geckos. 

If you want to keep your geckos singularly, a male might be better. They do well when kept alone, and you would not have to worry about egg binding all the time. 

Can You Influence The Sex Of Baby Crested Geckos?

In short, no, you can’t. Some species of gecko do not have sex chromosomes which determine whether the babies will be male or female.

Instead, the temperature at which the eggs are incubated can determine this. This process is called temperature-dependent sex determination or TSD. 

Crested Geckos do not develop as male or female dependent on TSD. Instead, they have sex chromosome determination, meaning that their sex is defined by their genetic code.

Crested Geckos have a ZZ/ZX sex chromosome system (humans have an XX/XY sex chromosome system). 

Crested Geckos have a 1:1 ratio of boy to girl offspring. This means that in any group of hatchlings, half are likely to be female and half male. This is determined at conception, so, it is not possible to influence the sex of baby Crested Geckos. 

You’re Ready For The Gender Reveal

Now you are well equipped to identify the gender of your pet Crested Gecko. Once you know this you will be able to provide the best care, house them correctly, and of course, pick an awesome name. Have a fantastic gender reveal party!