Breeding Green Tree Pythons (step by step guide)

Successfully breeding green tree pythons, incubating the eggs and establishing newborns is a bit more challenging than many other snake species.

Fortunately you have this guide to walk you through every step!

Before Breeding Your Green Tree Pythons

It’s very important that both the male and female are healthy prior to breeding, as the process is very taxing on both animals. Especially the female whose body has to endure the stress of producing the eggs.

Females should weigh at least two and a half to three pounds before being bred. This usually happens when they are around three to four years old.
Males are smaller than females and can weigh much less, but should still be three years of age or older.

Prepare The Green Tree Pythons For Breeding

Green tree pythons are seasonal breeders. Changes in temperature, known as thermal cycling, are what trigger their breeding instincts.

Start by slowly lowering the night time temperatures of the enclosures by one degree every three days, until you reach 68 degrees.
Lower the daytime temperature by one degree every week until you have lowered it by four degrees.
The male will most likely begin refusing food during this process. This is to be expected and is perfectly normal.
One week after you have reached 68 degrees at night, introduce the male into the females cage and leave it there.
Keep the snakes together and maintain those low temperatures until breeding has occurred, or up to five weeks.

You should move the male into the female’s cage during the day. This will reduce the chance that she strikes or bites, thinking there is food.

This thermal cycling of your snakes should provoke them to breed. In fact they will often copulate the first night they are placed together.

The Green Tree Python Breeding Process

Copulation generally happens at night, and they can stay joined for several hours. Even if you have witnessed them copulating, you will still want to keep them together.

Females can continue to be fed during this time, and will probably be hungrier than normal. Males will typically not be interested in food.

Keep the snakes together for four to six weeks, or until they are finished.

Signs that copulation is complete

The female will begin to lose interest in food.
The female’s color may begin to change slightly, becoming a bit duller and perhaps taking on a bluish hue.
You should notice that the male has lost interest in the female.
The male might also become protective of the female, and perch on top of her.

If you carefully observe your pythons, you will see when the female begins to ovulate.

Her midsection will swell as if she has eaten a huge meal. This swelling lasts for 12-48 hours, and some females are good at hiding it, so you may need to watch carefully if you want to notice it.

After Your Green Tree Pythons Breed

Once breeding is complete, both snakes can be returned to normal temperatures, and to their separate enclosures.

Make sure a good temperature gradient is available in the enclosure so the female can find the spot that is most comfortable for her. There should be a basking spot as well.

Approximately 25 days after ovulation, the female green tree python will have what is called a “pre-lay shed”. This shed indicates that she will be laying eggs in the next 14-21 days.

It’s time to prepare nest box!

Nest Box

A nest box is where she will go to lay her eggs.

This is basically a box that measures 8-10 inches on each side and is around a foot tall. You can go slightly bigger or slightly smaller. The idea is to provide her a hiding spot where she will feel safe to hide and lay her eggs.

Some people use small plastic totes with a 3” entrance hole cut in the side. You can also make a wooden box with a side entrance if you’d like.

Regardless of the material you choose, it should have a lid in order for you to have easy access.

The breeding nest box should also be mounted inside the enclosure about half way up, and should be easily accessible by her.

I recommend having the box on the warm side of the cage, but not directly in the basking area. You want the inside of the box to be around 84-85 degrees.

Inside of the box you will want to place some nesting material. This can be newspaper, dry sphagnum moss, coconut fiber…basically a material that she can use to create a secure nest, and which will help prevent the eggs from sticking to the box itself.

Green Tree Python Egg Laying

The moment has finally arrived!

Green tree pythons typically lay their eggs in the morning, and may take several hours to lay them all.

Average clutch sizes are between 12 and 18 eggs, though it is possible to have 40 or more.

Once the eggs are laid, the female will coil up on top of them in order to incubate them. While this is the natural way it would be done in the wild, there are several drawbacks you should be aware of.

You will not be able to monitor all of the eggs. One bad egg in the clutch could cost you all of them.
The female will not eat while incubating her own eggs, which puts additional stress on her.
Because she will not be eating, it will take more time for her to recover.
She will probably not be able to be bred the following season.

The alternative is to incubate the eggs yourself.

Incubating Green Tree Python Eggs

Incubating green tree python eggs is easier than you think, plus there are lots of quality incubators available on the market.

The keys to successful incubation:

Maintain a humidity level of 90% or slightly higher.
Keeping the surface of the eggs dry.
Maintain a constant temperature 86-88 degrees.

There are three main ways to incubate green tree python eggs.

Homemade incubator: A homemade incubator can be made using a plastic box without the lid, filled with dry sphagnum moss where the eggs will be laid. This box will be placed in a larger box filled with vermiculite and water at a 1:1 ratio. Holes are drilled in the side to allow air to enter and to prevent mold. This box in a box set up is then kept at 86-88 degrees.
1. The upside to a homemade enclosure is the cost. They can be made for just a few dollars.
2. The downside is the lack of exact control. There are a lot of variables that need to be accounted for, and constant monitoring is required.
Commercial incubator with substrate: The classic incubator is an enclosure that maintains a very precise temperature range. Eggs are placed on a substrate such as dry sphagnum moss, and water is in a heated pan to provide humidity. Vents and fans allow for air flow.
Commercial incubator without substrate: One of the newer methods involves an incubator where the eggs are suspended over water without the use of any substrate. This allows for better air flow around the entire egg. At day 49 the water is replaced with damp paper towels to prevent babies from drowning when they hatch.

Incubating tips

The eggs should be pulled out and separated as soon as possible. They are very sticky, and you might damage them as you pull them apart if they sit for too long.
Shine a bright light through the egg to locate the embryo. The embryo should be facing up when you put the egg in the incubator.
Mark the “top” of the egg (the side with the embryo) with a marker. This way if you move the egg, you will be able to place it back in its original position.
Some denting of the eggs is to be expected. If they begin caving in too much, or appear too dehydrated, increase humidity.

Green tree python eggs take around 50 days to hatch.

Many breeders will place a few perches near the eggs for babies to climb onto once they hatch.

Green Tree Python Neonates

Congratulations! You have baby green tree pythons!

Now what should you do with them?

Neonates should be housed individually in their own enclosures. They don’t have to be large cages, simply something around the size of a shoe box.

This should work for their first year of life. Set up the same type of enclosure as you would for adults with multiple perches for them to choose from, a basking spot, high humidity and a temperature gradient from one side of the enclosure to the other.

To learn more about general care, check out our green tree python care guide.

Feeding Baby Green Tree Pythons

After your neonates have had their first shed, they can be offered their first meal. This can be one of the most challenging aspects in the entire breeding process.

I always prefer to start my snakes immediately on pre-killed, or frozen/thawed food. Day old pinkie mice are the perfect size for babies, and can be fed using forceps.

Some neonates will take their first meal right away, while others will need lots of time, patience and persistence.

Here are some tips for finicky eaters.

Baby Green Tree Python Feeding Tips

Lower the lights and feed in the evening. This is when most green tree pythons hunt.
Replicate the preys natural movement. Babies in the wild typically start off eating small lizards and frogs. These animals dart or hop around quickly, and are often times lured in by the pythons tail. Start low, and “hop” the prey up to the snakes tail like a frog.
Change the scent of the pinkie mouse. Clean it off to remove the mouse smell, then rub the mouse on a baby chic, gecko or a frog.
Scent the mouse with pasteurized egg whites. This greatly reduces the chance of salmonella, and gives a scent the baby might prefer. We do not recommend you use raw eggs or chicken.
Instead of thawing the pinkie mouse in water, try thawing in chicken broth.
If none of the above work, I have one more trick for you. It’s not for the squeamish, but you’ve elected to breed an advanced snake which means you have to be willing to go above and beyond.
- Take a live pinky mouse, and slam it against a solid surface. This should immediately kill the mouse, and hopefully cause its face to bleed a little. Snakes are attracted to the smell of blood and especially brain matter.
- You want to immediately offer this to the snake while the body temperature is still warm.
- Using tongs, long tweezers or forceps, gently rub the mouse against the snout of the snake.
- At the same time, use something else (like a long wooden spoon) to rub the snakes tail.
- Here is the idea behind all of this. The scent should entice the snake. Bothering its tail should aggravate the snake and entice it to bite. Doing both at the same time should make it seem like a mouse is crawling on the snake.

You may notice that I did NOT mention force feeding your snake.

Force feeding should be an absolute LAST resort! It should also only be done by a trained professional such as a veterinarian.

I only recommend taking this step if your snake has not only refused all food, but is also losing considerable body mass.

Force feeding your snake can cause tons of additional future issues. Additionally, if your baby python has refused food up to this point there may be underlying health issues that need to be diagnosed by a veterinarian.

Summary

The two most important steps in this entire process are starting with healthy adults, and maintaining solid husbandry practices.

If those two things are not in place, you are setting yourself, your snakes, and any potential babies up for disaster.

Do those two things and follow the steps in this guide, and you should find success.

Happy breeding!