Female snakes lay eggs or give birth to live young 1-2 times per year. However, the most interesting thing to learn is how snakes reproduce. The female will let the male know when she’s ready to mate by releasing pheromones (scent/odor) from the skin glands located on her back.
Most snakes reproduce sexually, but some reproduce asexually. They mate in the spring after hibernation, using pheromones to attract mates. A male snake mates with a female snake by inserting one of his hemipenes into the female’s cloaca. This fertilizes the eggs inside her oviduct. A month after, she lays her eggs, which hatch two months later. Other species, such as boas, give birth to live young.
We’ll cover everything you need to know about the reproduction cycle of snakes, from snake sex organ anatomy to how snakes form eggs.
Snake Reproduction Cycle
Snakes don’t have reproductive organs. From the outside, snakes don’t display sexual dimorphism (the visual differences between the sexes.)
In snakes, you can’t tell the difference between male and female snakes externally. How does a snake that’s looking to mate tell the differences between male and female snakes?
According to the journal Behaviour, there is a combination of pheromones that a snake detects when he discovers a female snake of the same species.
A male snake presses his chin onto the female’s back. He then runs up along her back, all the way to her head. In doing so, he picks up the pheromones that tell him that the snake is female.
What Are the Differences Between Male and Female Snakes?
Male snakes have two organs called hemipenes. These are like the snake’s penis. It has two, which are kept inside the cloaca.
They’re held in place by the retractor muscle. When reproduction occurs, the two hemipenes are ‘everted,’ which means that they pop out of the cloaca. They also have testes inside their bodies, near their other organs.
The female snake has a cloaca. However, female snakes have ovaries that produce eggs, which males don’t have. They also have an oviduct, which is where the reproductive eggs develop into the eggs that she lays.
In many species of snakes, the female is larger than the male. According to the Proceedings of the Royal Society, different reproductive roles favor different sized body components. Here are the key differences:
- Females: The organ systems that store energy are enlarged. This includes the digestive tract, the liver, and places where they store fat in their body. These stores give them the additional energy that’s needed when they have to develop their eggs.
- Males: They have enlarged skeletal muscles, larger tails, and better functioning kidneys. The scientists suggested that this would assist them when searching for a mate, when fighting with other females, and in creating healthier sperm.
The scientists dissected 243 specimens from three species, including two colubrids and a viper.
What Is The Purpose of the Cloaca in Snakes?
The cloaca is the part of a snake’s anatomy that is used for both excretion and mating. It’s an essential part of a snake’s basic anatomy.
According to ResearchGate, the cloaca is made up of 3 distinct parts:
|Coprodeum:||This part collects feces from the colon. It is the first, and largest, section of the cloaca.|
|Urodeum:||This part collects urine and any products of reproduction.|
|Proctodeum:||This part excretes any waste.|
The female cloaca is shallow compared to the male’s, which is longer and extends further down the tail. This is because the male’s cloaca contains the two hemipenes.
These have to be contained inside, or they would drag along the floor behind the snake which would damage them. All mating in snakes is done using the cloaca and hemipenes.
When is Snake Mating Season?
Snakes emerge from hibernation in the spring, which is when mating begins. Snakes in northern, colder climates go into full hibernation.
This is an extended period of almost complete sleep. Snakes in the south will only go through brumation. Once a snake emerges from hibernation or brumation in the Sprint, the snakes will start mating.
The reason for this timing is that snakes are ectotherms. That means that they can’t produce body heat because they’re cold-blooded.
If a female snake was to lay eggs at the wrong time of year, both she and her clutch would have great difficulty staying warm.
How Do Snakes Attract Mates?
Snakes attract mates using pheromones. Females produce estrogen, and it plays a significant role in attracting males.
A study in the Journal of Experimental Biology found that boosting a male snake’s estrogen led to new pheromones.
These pheromones were the same as produced by a female snake. This really confused the garter snakes in the study, so that they would start trying to mate with the male.
Garter snakes rely on pheromones to facilitate mating. The male must lick the female to determine which pheromones and chemicals they give off.
They use a sixth sense, called the vomeronasal system, that’s focused on identifying specific pheromones. A snake can find out the species, sex, reproductive condition, size, and age of their ‘potential’ partner.
Do Snakes Mate for Life?
Male snakes are attracted to the most viable female based on her pheromones. The female that creates the best-smelling pheromones is probably the healthiest, so that’s the one that he’ll opt for.
Once the two snakes have mated, the male doesn’t usually stay with the female or care for his young. They go on to find other females, but there are exceptions to every rule.
According to the Royal Society, males of some species protect the female they’ve mated with to stop them from mating with any other snakes.
Not only that, but females that have already mated become less attractive to males, at least a Springer study on red-sided garter snakes.
There’s also another aspect to mating that prevents the snake from having multiple mates that have nothing to do with loyalty and love. Male snakes can produce what is called ‘mating plugs.’
Once the male has mated with the female, he can produce a gelatinous plug. The mating plug blocks up the female’s cloaca and stops any other males from being able to mate with her in that breeding season.
How Do Snakes Get Pregnant?
So, how does a snake fertilize an egg? Snakes mate by aligning themselves with one another, the male moving up along the female’s body.
He then inserts one of his hemipenes into the female’s cloaca. This is called the cloacal kiss because the two cloacae come into contact.
Most snakes’ hemipenes have ridges and spikes that perfectly fit the female cloaca to avoid slipping or otherwise moving away.
This aids in reproduction, but also prevents interbreeding between different species of snake. It takes quite a while for snakes to mate, usually between an hour and a whole day.
Sperm in snakes is produced in the testes. These are located inside the body cavity, near the stomach and liver.
The sperm travels along a duct, through a ridge in the hemipenis and into the female’s cloaca. This sperm fertilizes the female’s eggs, which is how a snake gets pregnant.
How Do Snakes Mate?
It starts when the female snake releases pheromones from glands on her back. The location means that she leaves a trail of pheromones behind her, wherever she goes. The male finds the scent and follows the trail.
When the male finds the female, he does the following:
- Slides his way up her body. In some cases, he may wrap himself around her to make it more difficult for her to escape.
- Once he reaches her head, he bumps his chin into it multiple times.
- He then wraps his tail around hers to find her cloaca. At this point, his hemipenes will be extended.
- Once he finds the cloaca, the mating may last many hours.
- When done, the male will release a mating plug.
According to the Journal of Experimental Biology, male snakes can use up to 18% of their daily energy in the production of a mating plug, leaving him hungry and weaker in the process.
Snake Mating Ball To Get the Female
Snakes can mate in a unique shape, called a mating ball. It’s so-called because dozens of male snakes appear to be a big, writhing mass.
Inside this ‘mating ball,’ there may be dozens of males all competing for the attention of just one female. Why do snakes mate in a ball?
Only the strongest, fastest, and fittest snakes will be able to reproduce. This ensures that baby snakes are most likely to be strong, like their parents. This is the basis of natural selection. It’s about the survival of the fittest.
Some male snakes have learned to disguise themselves as females, through secreting scents usually associated with females ready to breed. The theory is that this catches out the first males so that the pretend-female gets a better chance of mating with the female.
Do female snakes eat the male after mating? Not usually, but green anacondas in Brazil do. Records of a trek in National Geographic has an incredible story and picture of this happening.
It shows a female, as thick and wide as a truck tire, constricting her mate. The writers thought that it could be because the male is a good source of protein and nutrients to an expecting mother.
Snake Asexual Reproduction
Snakes are one of a small group of animals that can reproduce asexually. The flower pot snake is one example. The females of the species can produce young through a process called parthenogenesis.
In doing so, they can create clones of themselves. Depending on the exact scientific process, these can be either full clones or half-clones, depending on the amount of genetic material inherited by their young.
A study in Biology Letters looked at the issue, specifically in North American pitviper snakes, including copperheads and cottonmouths. Both of these species can reproduce asexually.
It’s possible for a female to store sperm in her cloaca for up to six years, and that sperm remains healthy. She might suddenly become pregnant.
Snakes can reproduce asexually, but that doesn’t mean that they’ve mated with themselves. Mating refers to the act of two snakes breeding.
Can Different Species of Snakes Interbreed?
All species of snakes have differently shaped hemipenes and cloacae. In a way, they’re reminiscent of keys and locks. A key that is used to unlock the wrong kind of lock won’t work. However, it’s still possible for two different species to breed together.
It all depends on what you mean by different ‘species,’ and to unravel that idea, we have to go back to basic biology.
In biological classification, there are eight significant levels. At the bottom are the species. Then, moving upwards, we have a genus, family, order, and class. Let’s use the corn snake as an example:
|Species:||This is the corn snake itself, defined by its colors and habitat, which is unique among snakes.|
|Genus:||Corn snakes are in the genus Pantherophis, also known as rat snakes. There are about a dozen different rat snakes. They’re all constrictors that eat rodents.|
|Family:||Corn snakes are Colubrids, a big group that contains Pantherophis and other families.|
|Suborder:||Corn snakes are in the suborder Serpentes, which contains all snakes.|
|Order:||Corn snakes are in the order Squamata, which contains most lizards and reptiles.|
|Class:||Corn snakes are in the order Reptilia, containing all reptiles.|
Breeding two snakes of the same subspecies together is not a problem. That means that having two varieties of corn snake breed is fine.
Corn snakes are almost unique in that they can breed with a startling number of other species from the same genus, even the same family. Corn snakes can interbreed with the following snakes:
- California Kingsnakes. When a corn snake mates with a California Kingsnake, they create what’s been termed a ‘Jungle Corn.’
- Gopher Snakes. A hybrid between a gopher snake and a corn snake is called a ‘Gopher Corn’ or a ‘Turbo Corn.’
- Great Plains Rat Snakes. A hybrid between an albino corn snake and a Great Plains Rat Snake is called a ‘Creamsicle Corn.’
The unusual thing is that these hybrid snakes are fertile. This is not usually the case. Take the offspring of a lion and a tiger (they produce a ‘liger.’)
According to a biological rule named Haldane’s rule, when two species interbreed, the males are usually sterile. Ligers follow this rule, but corn snake hybrids don’t.
How Do Snakes Give Birth to Eggs?
Some snakes give birth to eggs, and some snakes give birth to live young. Corn snakes, for example, lay eggs. Sea snakes, by contrast, give birth to live young. There are 3 different ways that snakes produce their young:
|Oviparous:||These snakes give birth to eggs. Around 70% of snakes are oviparous, as are the vast majority of Colubrids.|
|Ovoviviparous:||These snakes develop the eggs within their body, but the eggs hatch inside her. She then gives birth to live young. Rattlesnakes are ovoviviparous snakes.|
|Viviparous:||They give birth to live young, and at no point is there an egg involved. The young develop inside a placenta and yolk sack. Boa constrictors are viviparous.|
With regard to oviparous snakes, after mating, the snake will find the ideal place to lay her eggs. This is called oviposition. The location has to be sheltered so that it doesn’t get too cold. Remember, snakes are cold-blooded.
The development of the eggs takes place within the female herself. The snake pushes her eggs out from her uterus and through the cloaca using muscle contractions.
The eggs are pushed out one after the other, steadily, until the female has birthed them all. The eggs stick together so that they can’t roll around, which might damage the baby snakes inside.
After they give birth, the vast majority of female snakes then abandon their eggs, leaving the babies to fend for themselves. However, some do stay with their eggs to protect and warm them. Pythons are one example.
How Do Snakes Make Eggs?
The process of making eggs largely takes place in the oviduct, which is the tube that connects the ovaries with the uterus.
The eggs are released from the ovaries. As they travel to the uterus, they are coated with a special secretion. In combination with protein fibers released in the uterus, they create the egg’s shell.
Snake eggs are more uniform throughout, whereas other kinds of eggshell have several layers made from different materials.
According to PLOS One, snake eggs only have a superficial coating of these protective, semipermeable crystals. This gives the eggs a different feel to ‘normal’ eggs. Instead of being brittle and thin, they’re leathery and thick.
The eggs then gestate until they’re ready to be birthed. This takes many weeks, throughout which the eggs develop, becoming larger.
How Long Does It Take for a Snake to Lay Eggs?
From the moment of mating until the eggs are laid, the process takes about 30 to 45 days. Eggs and young take the same amount of time to develop, regardless of whether the snake is big or small. Snakes have a relatively short gestation period compared to mammals.
If your snake is pregnant and you’re waiting for her to give birth, that’s a sign that she’s closing in on her due date, apart from the fact that they’re getting bigger around the middle.
About four weeks after mating, your snake will start her prenatal shed. This is just like any other shed, but it’s a useful marker for when she’s about to begin birthing her eggs or young.
From the moment she starts birthing, it usually takes a snake 24 hours to lay all of her eggs. The smaller the snake, the fewer eggs she’ll lay. The largest constrictors lay up to 100 eggs each time they birth.
However, birthing isn’t always without its problems. It’s possible for your snake to become egg-bound, meaning that there’s an egg that’s too big or too broken to birth.