In this complete uromastyx breeding guide, you will learn about uromastyx breeding age, when uromastyx start breeding, how to prepare uromastyx for breeding and how to incubate eggs. You will also learn about breeding behaviors in uromastyx, how to care for uromastyx eggs and hatchlings.
When do uromastyx reach sexual maturity? Breeding age.
Uromastyx are truly slow growers, and take a long time to reach sexual maturity and adulthood. Most uromastyx reach sexual maturity and adulthood by the age of 3-4, some can take up to 5 years.
When do uromastyx breed?
In the wild, uromastyx will brumate through the cooler winter months and then become active and interested in breeding in the early spring, in early March. These times will be different in Southern Hemisphere (Australia etc.).
And in captivity, the best practice is to let uromastyx brumate for around 2-3 months and then return to usual conditions. This will condition uromastyx and promote their breeding interest.
How to tell the gender of uromastyx?
Determining uromastyx gender is not easy, and most will not show any characteristics until they turn around 3 years old. Some species will have males that are more vividly colored than females.
The most reliable way to tell the sex of your uromastyx is by looking if there are hemipenal bulges on both sides of the tail, as well as femoral pores. Femoral pores run along the thighs – male pores will be much more prominent. However, u.princeps and u.benti do not have any femoral pores.
How to prepare uromastyx for breeding?
- Prepare your potential pair for breeding – make sure they are healthy and the same species. Never mix species of different uromastyx – bloodlines are very important.
- Take your uromastyx through a cooling period. This increases the chances of a successful mating when brumation is over.
Encouraging cooling/brumation in winter – to prepare uromastyx for breeding in spring
Encouraging a cooling period/brumation highly increases the chances of your uromastyx starting spring with a high interest in breeding. Most uromastyx come out of brumation ready to breed within few weeks.
However, only cool uromastyx that are mature and healthy, and ready to breed next season. If your uromastyx are skinny or showing any signs of sickness, don’t induce brumation.
To cool your uromastyx, you will need to decrease the temperatures in the tank slowly, as well as the number of daylight hours. You can start in the mid November, by reducing the amount of food you are offering.
Give your uromastyx around a week to properly digest food, and stop offering any more. However, you can leave a small water dish in there.
Towards the mid-end November, start reducing temperatures to around 75-80 F (23.8 C) in the background over a few week period (not abruptly). At night, temperature should drop to 65-70 F (18-21).
Over few weeks, reduce the number of daylight hours to 8-9, while still offering food, and then down to 6-7. At the same time, reduce the food that you give, before you stop offering any when you reach 6-7 hours of daylight per day.
You can reduce 1-1.5 hours of daylight per week until you reach 6-7 hours. After brumation ends, increase them the same way.
When brumation starts, you can change the timer to turn the basking light on 4-5 times a week, for around 3-4 hours a day. This will help reach temperatures of around 85 F (29.4 C), to mimic daytime temperatures. As lights will be on only for few hours, temperatures won’t raise higher. If they do, reduce the bulb wattage.
Brumation period
During brumation, your uromastyx might come out for few hours every few days – they won’t be in deep sleep. They will just have less energy to move around due to low temperatures and no food. Offer a water dish every few days, or tap some water on its mouth. Every few days, check on them, to make sure they are well.
Once in few weeks, you can soak your uro, but make sure to dry it properly before returning to the tank. You can offer a little bit of food every few days, but nothing much. If you offer food, you must have the basking light on.
Cooling period can last until end of February. Towards the end of February, start increasing temperatures and number of daylight hours form 8-9 to 12, and then 14 towards late spring. Do it gradually, so that it mimics a natural photoperiod. Make sure to keep humidity low (20-30%)! Otherwise, it will cause health issues!
End of brumation and start of the breeding period
You will need to return daylight cycle and temperatures to normal towards the end of February. By then, your uromastyx will start to become more active. They will also start eating soon after.
Give them around a week or two to fully come out of brumation. Make sure temperatures are correct, offer fresh veggies and greens dusted with calcium and multivitamins. Help your uromastyx hydrate as well.
Make sure that your uromastyx, especially female, has not lost weight and is ready to carry eggs. If they have lost some weight, concentrate of feeding and getting back to normal weight first.
Your uromastyx might also shed during this time. Let them get back to normal for around 3-4 weeks before you attempt breeding them. And only allow the female to breed if she’s healthy, eating and pooping.
Breeding uromastyx
As mentioned above, you can start breeding uromastyx in mid-late March, few weeks after the end of brumation. Make sure both female and male have started eating normally, and that female is healthy and has not lost weight before you breed them.
Only breed the same species, as maintaining bloodlines is crucial – do not mix different species. Babies of mixed species might not survive and might develop serious health issues.
Once you are ready to breed uromastyx, introduce a male to a female. Once they are together, the male will go around the female. Breeding behaviors include marking the territory by rubbing, quick head bobbing and chasing. If she is ready to mate, he will bite her on the neck and mate. However, if a female is not ready, she will turn upside down and lay on her back.
You can allow few mating sessions to have a better chance of fertility – leave the pair together for up to few days. But only do this if the tank is big enough – at least 68 inches (152cm) long. Monitor their behavior – if you notice any fighting or a male stressing the female, separate them immediately.
In some cases, female might be so unwilling to mate, that she will fight with a male. You must separate them immediately, and try later, or find another male. Females also often become aggressive towards males after becoming gravid.
Uromastyx gravidity and preparing for egg-laying
Once your uromastyx have mated once, or better few times, separate them. Uromastyx don’t need to stay in pairs, and they don’t feel any connection. Make sure to house a female alone from now on.
Your uromastyx will be pregnant (gravid) for around 4-5 weeks until she lays the eggs. She will look big – her belly with stretch sideways and you will see the outlines of eggs. You must create a laying box for your female uromastyx, so she can lay the eggs there. Prepare it straight away, so she can get used to it and use it when the time comes.
To make a laying/next box, use a large box (such as shoe box that she can enter and turn around in) and fill with sand and moist vermiculite like this for substrate. You can also use a plastic box that will have a large entrance on ground level. You can also cut the lid in half so she can climb from top (make sure it’s easy to do so).
4 parts of substrate and 1 part of water should be optimal. It should clump in your hands, and not drip and water. Fill the box to about 5-7 inches (13-18 cm) of substrate, that she will dig to lay eggs.
Make sure that female has laid all the eggs – make sure she is fully done and is not digging anymore. Sometimes, egg binding can happen, and female will need a surgical remove of the egg. The best thing to do would be to take the female to the vet for an X-Ray, to see if there’s anything left inside.
After the eggs have been laid, you will need to remove them straight away and incubate them. When moving eggs, do not rotate them as you can kill the embryo in the egg.
Incubating uromastyx eggs
Once eggs have been laid, carefully pick them up and put them in a ready incubator, in the same position. Bury around half of egg (around 50-60%) in the substrate to provide moisture.
There must be at least 3 inches (8cm) of medium so that any excess moisture sits on the bottom and doesn’t touch eggs (could cause molding). Leave 2-3 inches between eggs. Use vermiculite or a special reptile clay incubation medium like this for substrate, because it will help hold humidity better.
You can place eggs in a medium Tupperware box. Whatever you choose, you must incubate the eggs on moist substrate (but not dripping wet – about 60% humidity) at 85-90 degrees F (29.5-32.2 Celsius).
Fill the box with moist vermiculite or the special clay incubation medium to provide moisture to the eggs. Make sure that vermiculite is moist, but not wet – 1 par of water to 3-4 parts vermiculite is optimal. If you get an incubation medium, follow instructions.
Incubating eggs in a commercial incubator
For a better chance of hatchling survival, you can incubate the eggs in an incubator like this. Commercial incubators will maintain desired temperatures and humidity, as well as control them.
There are different types of incubators that you can get – the main goal is to keep the eggs in stable conditions (temperature & humidity). There are reptile and chicken egg incubators. This can be hard to achieve without a regulated incubator.
Incubating uromastyx eggs without a home incubator
However, if you decide to make your own incubator, it is possible. But you will need to check on the conditions up to few times a day, as well as maintain humidity. Please be vigilant if you are going to use your own incubator.
Make sure to test it before you put the eggs in there – so prepare it while the female is still gravid. Test the temperatures inside by moving the probe to different spots of the box.
To make a DIY incubator, you can fill the plastic box with the substrate and lay the eggs on top. Then, place this box with eggs inside a larger box. Then fill it water, and heat the water with a submersible water heater like this.
The lid of the large box must have holes for ventilation. You will need to place a hygrometer and thermometer inside the box with eggs to monitor temperatures. Make a hole on the side and put the probes through it.
Another option is to use an under tank heating pad like this, to heat the box from underneath without water. For this, also put all the eggs in box with a substrate and put into another bigger box.
Place the box with eggs on a small shelf, and a heating pad under. Make sure the heating pad doesn’t touch the box inside with eggs directly, so elevate it. In the big box, you can also place a small dish with water for humidity.
Make sure the top lid has holes for ventilation. Once or twice a week, take the lid off to allow proper ventilation. Put the lid on after some time (around 30 minutes of ventilation).
Make sure to use a thermostat will all heating devices to control temperatures!
Uromastyx eggs hatching
After 2-2.5 months of incubation, the eggs should start hatching. Hatchlings will break the top of an egg and slowly come out. Some hatchlings might take a day or two to come out – don’t pull them out as it can cause long-term injuries.
Babies will feed on the leftover egg yolk, so there is no need to pull them out of the egg. Most hatchlings will start eating within few days.
How many eggs do uromastyx lay?
Uromastyx lay around 8-20, up to 25 eggs, around 4-5 weeks after mating. You will also need to incubate eggs for around 2-2.5 months before they will hatch. However, some eggs might not be fertile or won’t hatch after incubation.
How to care for hatchling uromastyx?
Right after hatching, place your hatchlings inside a medium sized tank (30-40 gallons). Provide a lot of chopped fresh vegetables and greens. Also place a very shallow bowl of water few times a week, so that they can drink. Make sure temperatures are appropriate and that there is a UVB source.
Basically, set up everything as you would do for an adult uromastyx. However, make sure to add a lot of hides – you can skip including decorations or plants for the first few months of their lives.
Make sure hides are small, as this way uromastyx feel safe. They like to squeeze themselves in tight places and feel the hide on their belly and back.
You can house some babies together in a 30-40 gallon tank for the first 2-3 months. After that, move them to a bigger and separate them. By separating uromastyx, you will increase their chances of eating and growing properly without any competition. Don’t introduce any loose substrate until they turn at least 4-5 months old.
Thank you for reading this uromastyx breeding guide! To learn more about uromastyx care, please see this resource page.