Some types of uromastyx are sexually dimorphic. This means that males and females have unique features making them easy to tell apart. Often males are more colorful than females. Males may also be wider at the tail base and have larger heads.
Another possible way to determine the sex is to check the femoral pores of a mature uromastyx. These pores are along the underside of the thighs. Males may have larger and more distinct pores. Generally, if the pores are easy to see, the uromastyx is a male.
You can also check for the hemipenile bulges. You hold the uromastyx in your hand ,stomach up, and bend the tail up toward the back at a 90* angle. If there are two bulges on either side of the tail base it is a male. If you see one centered bulge or no bulge it is female.
You must be vary careful that you do not bend the tail too far. You could break a vertebrae at the base of the tail.
Sexing a uromastyx can sometimes be difficult. If you are in doubt, asking a veterinarian to sex your pet is always an option.
Mating should occur in a neutral tank or the females home. When a male enters the cage, he will show off by bobbing up and down and chasing the female around the tank. The male should eventually grab hold of the back of the female’s neck and mate.
While the male courts, the female will run away and hide. If the female is not interested in mating, she will flip on her back. If the female mali uromastyx does not want to mate, the male should be removed from the tank. If the female is interested, the male should be removed from the tank after a day or two of mating.
Brumation is a period where a lizard will sleep a lot and eats very little. It often occurs during cold weather. A period of brumation may, or may not, be necessary, but often triggers the instinct for uromastyx to mate and breed.
Once a female uromastyx becomes pregnant, it will be 4 to 6 weeks until she lays her eggs. A place to lay her eggs should be added to the pregnant uromastyx’s tank.
The egg laying site should have several inches of moist play sand. The substrate should allow for her to dig, lay, and then bury her eggs. A plastic container about the size of a shoebox makes a good site.
Once the uromastyx has her egg laying spot the way she wants it and is ready, she will lay her eggs over the course of many hours. Depending on the type and size of uromastyx, she will lay between 10 and 20 eggs.
You should carefully uncover the uromastyx eggs and place them in a plastic container. Do not rotate or change the position of the eggs while moving them.
The bottom of the container should contain enough vermiculite to cover each egg 2/3 deep. The vermiculite should be mixed with water at a rate of 4 parts vermiculite to 1 part water. The container will also need a lid with air holes.
The easiest way to incubate eggs is to use a commercial incubator. Styrofoam incubators are inexpensive and work fairly well.
The temperature of the incubator should be right around 90*. You should keep the incubator in a room that is cooler than the temperature of the incubator. They are designed to raise and maintain one temperature. If the room is warmer than the incubator, it will raise the temperature above the thermostat setting in the incubator and possibly kill the eggs.
To help maintain humidity levels, you can place a dish of water within the egg container and refill it as necessary. The eggs will hatch in about 60 to 70 days.
A baby uromastyx will open an egg with an egg tooth. Babies may leave the egg after opening it or stay in the egg for up to several days. Remaining in the egg is normal and is just a way for the uromastyx to absorb any leftover egg yolk. Once a baby leaves its egg, it can be moved to a new tank.
Baby uromastyx can be kept together and have similar requirements as adults. One difference is you probably shouldn’t use sand as a substrate. Plain paper towels or newspaper make a better substrate.
The main concern with sand is the fear of the babies eating it and causing an impaction. You should also make sure the food for the babies is finely chopped to make sure they have no trouble eating it.