In school, we all learn about the basic differences between mammals, birds, and reptiles! But, beyond that, many of us don’t get to learn much more about each group of animals. If you’ve found yourself as the proud owner of a reptile, you might have a lot of questions! If you have two, you might also be wondering if they’ll breed and lay eggs.
So, what reptiles lay eggs?
Most species of reptiles lay eggs and are called oviparous. Many lizards, snakes, and turtles lay clutches of eggs. Some reptiles give birth to live young and are considered ovoviviparous. Reptiles have evolved to have the best reproductive systems possible for their environments and might still be evolving and changing strategies today!
In this article, we’ll talk about which reptiles lay eggs and which don’t. We’ll discuss the process of each strategy and some of the pros and cons.
Which Reptiles Lay Eggs?
Most reptiles are egg layers. One of the basic requirements of being a reptile is the ability to lay eggs.
Below, we’ll go into detail about the birthing habits of specific reptiles. For now, we’ll list some large groups of reptiles that lay eggs.
Turtles are one group of reptiles that are exclusive egg-layers. No turtles give live birth. The female turtle will lay a large clutch of eggs and then usually leave them to hatch and fend for themselves. Turtles and tortoises in captivity might lay unfertilized eggs. These obviously won’t hatch, but don’t be alarmed if you feel like you’ve caught your pet red-handed!
Not all snakes lay eggs, but most do. One of the largest groups of snakes in the world is obligate egg layers; pythons. Most snakes need to mate in order to lay viable eggs. But some snakes, like ball pythons, can lay eggs without the presence of a male. This is done through the process of parthenogenesis and results in a bunch of babies that are clones of the mother.
Most snakes abandon their eggs after laying them, but some species will stay and incubate the eggs.
Like snakes, most types of lizards lay eggs.
Lizards usually don’t lay as many eggs as snakes or turtles do. Lizards usually lay their eggs in dark and moist areas to allow for the best chance of survival. One interesting fact about lizards is that in some species, live birth and egg-laying is possible. A skink that is found in Australia uses a different technique depending on where it lives in the country. It’s the same animal but has evolved.
How Many Eggs Do Reptiles Lay?
The amount of eggs reptiles lay varies greatly among different species.
The reptiles that lay the fewest eggs are lizards. Some animals like anoles only lay one egg at a time. They’ll never lay a large group of eggs at once. Turtles and crocodiles lay the most eggs of any reptile. Crocodiles might lay anywhere from 40-50 eggs in a clutch. Incredibly, sea turtles can lay more than 100 eggs at once.
For some animals, one clutch of eggs can have multiple sources of genes. Some of the eggs may be fertilized by one male, and the other eggs might not be. This gives the eggs great genetic diversity and a higher chance of survival overall.
What Type Of Eggs Do Reptiles Lay?
Just like with the number of eggs, the type of eggs you’ll see from a reptile all look very different.
The classic snake egg is a soft, leathery, pouch that is shaped like a long oval. If you’re lucky, you may have also seen tiny, fragile sea turtle eggs on a beach before. Some turtles also lay leathery eggs while others lay super strong and thick eggs.
The type of egg that an animal lays matches its body and environment. Snakes need to lay eggs that are long, otherwise, they wouldn’t be able to grow them in their thin torsos. Turtles like mud turtles lay super strong eggs that are buried underground. This helps to ensure that the eggs don’t break if they’re trampled.
Common Reptiles That Lay Eggs
To fully satisfy your curiosity, we have a list of some of the most common reptiles that lay eggs. These animals all have different and fascinating reproductive strategies. Not only is it interesting to know how reptiles have evolved to survive, but it’s also important to know how your pet reptile reproduces!
Bearded dragons are one common pet reptile that lay eggs.
Female bearded dragons will lay up to 20 eggs after mating. Females can also lay clutches of infertile eggs. The egg-laying season is a period of about four months. In those few months, bearded dragons can lay multiple groups of eggs. Beardies tend to become calcium deficient in the best of times (which is why a good diet is so important) so you’ll want to supplement gravid reptiles with extra calcium as soon as you know they’re carrying eggs.
Leopard geckos are similar to bearded dragons in the way that they lay eggs and reproduce. Like bearded dragons, geckos can lay fertile or infertile eggs after digging a small nest. After mating with males, females can lay multiple clutches of eggs over a 4 -5 month period. Leopard gecko eggs are small, soft, and oblong in shape.
Ball pythons have a more interesting approach to egg-laying than bearded dragons or leopard geckos.
Ball pythons are one species of snake that will stay on their eggs until they hatch. Ball pythons only lay between 1 – 11 eggs in a clutch. These eggs are sticky and will stay glued together while they incubate. After hatching, the babies are totally independent. Even so, they won’t stray far from mom for the first couple of months.
Green iguanas lay tons of eggs at once.
These huge lizards are known for their vegetarian diets and large clutches of 20 to 70 eggs! A female can spend up to three days laying all of the soft leathery eggs. The eggs are incubated in a burrow underground and mom does not sit on them. However, the mother iguana will come back multiple times to check on her eggs. The eggs take a whopping 3 months to hatch and are completely independent once they hatch.
Red-eared sliders can lay an impressive amount of eggs and also known for being relatively friendly with other herps.
While they’ll only lay between 10-30 per clutch, these reptiles can lay hundreds in just one year. Since red-eared sliders are semi-aquatic, they have an interesting strategy to protect their eggs. Female red-eared sliders are larger than males and use their strong back legs to create a safe space for their eggs.
Females will dig a hole with their hind legs and deposit an egg into that hole. They’ll immediately cover the hole up and move on to bury the next egg coming out. This helps to keep the eggs safe from predators and safe from floating away down a river!
Which Reptiles Give Live Birth?
Since most reptiles lay eggs, reptiles that give live birth are more of an anomaly!
But, there are still plenty of species of reptiles that do give live birth.
Some geckos have been known to give live birth, instead of laying eggs like their other gecko counterparts. Boas and vipers are two groups of snakes that give live birth, and young snakes come out of their mothers ready for action! Some skinks give birth to live young. Garter snakes are another common species you’ll never catch laying eggs.
But, the interesting thing about live birth for reptiles is that it looks a little different than live birth for mammals.
How Does It Work?
Reptiles who give live birth are called ovoviviparous.
Ovoviviparous animals are the bridge between egg-laying and true live birth animals. Ovoviviparous animals have eggs inside their bodies. These eggs develop while they’re still in the mother’s womb. Ovoviviparous animals either birth precocial live young or larvae, depending on the species. Most reptiles birth fully independent live young.
Ovoviviparous eggs are fertilized in the same way as other eggs. Instead of a placenta, babies survive on the yolk of the egg while still in the mother’s body. Ovoviviparity is a primitive strategy and helps to ensure that young have a great chance of survival once they’re out in the world.
Reptiles That Give Live Birth
There aren’t as many reptiles that give live birth as there are egg-laying reptiles. HOwever, there are enough to talk about and many of them are actually kept as pets!
Blue-tongued skinks are ovoviviparous reptiles.
Blue-tongued skinks make great pet reptiles, that are easy to handle and fun to observe as they’re quite active during the day. When these lizards become pregnant, they’ll carry eggs inside of them for a period of 3-5 months. They usually give birth in the winter and spring. Skinks are a little different from other ovoviviparous animals because they have a placenta. The babies grow and feed off of this placenta and emerge fully formed.
If you saw the video above, you already know that rosy boas give live birth!
Rosy boas don’t lay eggs, but instead, birth tiny live snakes. When the babies emerge, they’re born in thin membranous sacs. These sacs aren’t restrictive and any healthy babies won’t have trouble breaking themselves out.
Male and female members of this species mate with multiple partners during breeding seasons. This means that one litter of snakes might have the genes from a couple of different parents. If you have a rosy boa as a pet, be warned that you may have adopted them pregnant. Since they don’t lay eggs, you won’t know until you find a bunch of tiny snakes in your enclosure!
If you want to talk about dangerous reptiles, the gaboon viper is one to look out for, literally!
Gaboon vipers are deadly snakes that some people keep as pets. Gaboon vipers, like all viper species, give birth to live young. All vipers are venomous and have long fangs that penetrate prey to deliver deadly venom.
Gaboon vipers are pregnant for a span of 7 months but eventually give birth to 30-40 babies at once. Of course, these babies all come out fully functional and are able to bite and deliver venom. The
Jeweled geckos have a very interesting reproductive strategy!
They have a pretty similar pattern to many mammals. Jeweled geckos give live birth and only do so once a year. Females of this species are pregnant for 7 – 8 months at a time. While pregnant, the eggs developed and grow inside the female. In the autumn one or two geckos are born and are fully precocial.
Jeweled geckos aren’t legal as pets in most places, so to see them, you’ll need to venture out to a zoo or find these geckos in the wild.
The relatively small garter snakes are an anomaly in many ways in the reptile world!
Garter snakes are another species that give live birth. Garter snakes usually give birth once a year in August or September. A female garter snake can have up to 40 babies at once. Once garter snakes are born, they’re ready to take on the world. Not only are garter snakes interesting because of their reproductive cycles, but they also have a different diet than many other snakes. Garter snakes eat both animal and insect protein. They’ll happily eat anything from earthworms to small frogs!
Many reptiles lay eggs and just a few give live birth. Reptiles that lay eggs are turtles, tortoises, and many snake and lizard species. The few reptiles that don’t lay eggs, still have eggs that developed inside of their bodies before they give live birth. No matter what strategy they use, they’re still considered reptiles and are definitely some of the most fascinating animals in the world!