Green Tree Python Breeding Information

Green Tree Pythons are tricky breeders - they won't breed every year, they only will accept specific mates, and there is no "proven formula" like most other reptiles. It is definitely part science and part art.

That being said, breeding GTP's is one of the most rewarding things there is.

Sexing

As much as it seems sort of obvious you need to make sure you have a male and female animal before you can begin. One of the reasons this is worth mentioning here is that Green Tree Pythons can not be (safely) sexed as neonates, despite the oodles of "sexed" babies for sale. It is very common to find out 4-5 years later that in fact you haven't got what you think you do. Even worse - you do have the sex sold to you but that neonate sexing damaged the organs (as it almost always does) and the animals can't be bred.

The only reliable way to sex Green Tree Pythons is to probe them. All of the size and spur tricks are pretty useless with these animals. Using a properly sized special metal probe you can determine if it is male (7 to 9 scales deep) or a female (2 or 3 scales).

Probing GTP's is sketchy - it is really easy to injure the animal. If you haven't done it many times before either go see your vet or someone who really knows what they are doing. Do not allow inexperienced people to probe your animal and under no circumstances bring it to your local pet shop or reptile show for "free sexing" as this is pretty much a guaranteed disaster.

Putting two females together by mistake won't cause a problem but two males will engage in combat and can have significant injuries as a result.

Happy and Healthy?

Lots of folks have theories as to why exactly it is true but no one debates that it is the reality - only animals in perfect premium shape can be used in a breeding program. With other snakes there are ways to "push it" and muddle through, not so with Green Tree Pythons.

Remember what you are asking of them - especially the females - in some cases it is 5 months of no eating before babies are born. You've got to be one strong python to be able to do that, no doubt about it.

"Can be sexually active" is not the same as really "ready". It is our opinion that females need to be four years old and at least 1,000 grams. Some younger and smaller males will breed but usually not well , boys need to be three years old and 750 grams or more. Some females don't reach 1,000 grams until they are 5, same deal with the boys - they grow at their own rates. You can not change this by power feeding, you'll only make fat animals that won't breed.

Generally speaking being greedy will be counterproductive - animals bred at too young an age will never breed well throughout their lives. Slow and steady, there is always next year.

If any health problem exists the animal is out until at least the following year.One more time on that - any health problem within the last 12 months means you can't breed the animal.

About 2-3 months before you begin breeding you'll want to increase the frequency of meals. You don't want to make fat animals but you are going for a good bit of robustness. As females naturally eat like pigs at this time of year it isn't hard to do. Don't put the boys on quite the same program, remember that they just need to breed, they don't need to make eggs.

So you've got your perfect healthy slightly robust animals all ready to go and here is where the fun starts.

Cycling

So the first thing you have to do is convince your animals that it is the correct time of year for them to want to breed - you do this by cycling the environmental conditions. Green Tree PYthons do not hibernate and must always be given normal daytime temps or you will cause a health problem.

There are folks that do not manipulate the daylight cycle or the misting and they successfully produce animals. We feel that you might as well give your GTP's every indication that you can that the time is right for love so why not use every environmental factor that you can.

Over a period of about 6 weeks you'll reduce the temps and daylight period. You need to find what works for you, Green Tree Pythons can be cycled at anytime of year. It is best to work with mother nature and not fight her.

Here at Spruce Nubble Farm we are in the western mountains of Maine - middle of nowhere really but that's another story. We start cooling at the beginning of December and introduce animals in mid January. Here is our schedule:

Initial Conditions
Daytime = 88-90
Night = 85
Light = 14 hours (6 AM to 8 PM)

Week One
Daytime = 89
Night = 84
Light = 13 hours (6:30 AM to 7:30 PM)

Week Two
Daytime = 88
Night = 83
Light = 12 hours (7:00 AM to 7:00 PM)

Week Three
Daytime = 87
Night = 82
Light = 11 hours (7:30 AM to 6:30 PM)

Week Four
Daytime = 86
Night = 81
Light = 10 hours (8:00 AM to 6:00 PM)

Week Five
Daytime = 85
Night = 80
Light = 10 hours (8:00 AM to 6:00 PM)

Week Six & Through the Breeding
Daytime = 84
Night = 79
Light = 10 hours (8:00 AM to 6:00 PM)

You'll notice that we don't drop our temps much - it is our opinion that night time lows below seventy are just not necessary and can cause problems. With proper daytime temps some folks do like to really keep them cool at night but remember that what you want to do is achieve the minimum stress that will induce breeding - if they breed your cycling worked. Everyone has a different opinion here and you need to find what works for you. There is no "formula" that will always give results, you need to watch your animals and adjust accordingly.It is probable that the differential is more important than the actual temperature.

Gettin It On

So you've cycled your healthy animals and the day comes to put them together. You want to be sure to put the males into the females cage, not the other way around. Speaking of which, it is important to make sure that the females cage is ready for another occupant - you want sufficient perches so they don't hassle each other. We use free standing PVC "trees" which we put into breeding females cages.

It will help you to wait for a day when the weather is cooperating - an approaching storm is what is best. The late afternoon is the time to introduce the male to the females cage, this will give him time to get oriented before "lights out". We spray very heavily with newly introduced pairs as this seems to help them get going.

Observing your breeders is critical - some of them do not get along and they are capable of injuring each other. Most of the time you'll either get the male moving back and forth on top of the female (this is good) or they'll just ignore each other.

You may or may not ever see tails intertwined and actual breeding - but some animals will intertwine and stay that way for many hours. You'll usually get action on the first night if it is going to happen.

After about three days we remove the male and give him a rest of 2-3 days before reintroducing him. We'll keep doing this until they no longer seem interested in one another. It varies but the breeding "season" lasts about two months.

Because Green Tree Pythons engage in male combat in the wild the shed skin of another male placed into the cage with a breeding pair can sometimes stimulate action. This is not that different than "Scenting"" a prey item.

The list of tricks to inspire the love is pretty bottomless - as long as it is safe for the animals there is little harm in trying almost anything. You have to figure out what works for you and your animals. Remember that females tend to be firm and faithful in their choices on males.

Returning the Nighttime Heat

So once your pairs are done breeding - or if you see an ovulation (described below) it is time to give them back night time heat. We basically invert the cooling schedule above but do it a little bit faster. Some people feel this is a critical part of the breeding process - whether this is true or not really isn't worth worrying about. Who would possibly want to test this by not providing proper conditions to animals they know have bred?

Once the boys have had a little bit of time back at normal temps they'll be interested in food again. They are in recovery mode. Sometimes they can be stubborn about that first meal and will insist on a live prey item.

Follicles and Ovulation

There is lots of confusion on this issue and sequence. Some females make this much more obvious than others - there are two basic events.

Follicle formation is when you see the ova getting ready to go.

Ovulation is when the ova are released from the ovary.

The first reason for the confusion here is that both of these things cause body swelling and atypical postures, aka weird coiling. The way to tell the difference is that ovulation is fast and local. It comes on quickly, lasts about a day or so, and then goes away quickly. It looks like the animal swallowed a baseball - but it appears and disappears quickly.

The other reason this is confusing is because there is no predictable timeframe - females might develop follicles and ovulate anywhere from five to seventy days after breeding - so it might be a week or it might be more than two months. It should now make perfect sense why Green Tree Pythons don't have a typical hatching "season" among breeders.

Don't worry - as you begin to see and observe these events it'll quickly get to a point of pretty obvious recognition.

The reason everyone wants to pin down ovulation is that once they ovulate they get back on a predicable schedule. About thirty to forty days from ovulation they shed, and then you can set your watches.

Pre Lay Shed & The Nestbox

Green Tree Pythons do so few things reliably - but they all shed before they lay eggs. Well - just to prove the point that the words "all" and "GTP" should never be used in the same sentence there have been a few (very few) recorded instances of females laying eggs without shedding. But anyway - when they shed it'll be 14 days until the eggs are laid.

The pre lay shed is when we place nest boxes in the cages - we use 8" plastic boxes lined with dry spagnum moss. We place them on the floor of our cages but some folks like to mount them a bit higher - that doesn't seem to impact acceptance of the box which is the important thing.

You need to make sure the temps are correct - about 85 degrees on the floor of the box. A small heat pad right on the bottom of the box may be needed but if you use one be sure to attach it to a thermostat that has a probe inside the box. If it isn't comfy she won't accept the box, variance of even a few degrees can make the location unacceptable. Usually females will enter the box just a few days before egg laying but some will enter earlier. They tend to get restless before egg laying time and will often enter and exit the box many times. Lots of folks observe this behavior carefully and have of faith in the "signs" - we don't.

You need to consider whether or not your female is accepting the nest box you have provided. If she is always cruising the cage and not going in the box that is an indication she has not accepted it. The problem is that they tend to do two things if they don't like the nest - lay eggs in the water bowl or drop them from the perch. Is she does either of these things you will scream out loud for quite some time and annoy the other members of your family.

While it is worth finding a nest box your female will accept the thing to do if the time is approaching and she is not going in the box is to remove the water bowl and all perches from the enclosure. Coat the entire bottom of the cage in dry spag moss. This is a lousy solution but it better than losing a clutch. Maternal incubation is unlikely to work if she doesn't lay in a nest box.

So the big day finally comes - they usually lay eggs in the morning. One of the things we like about the commercial nest boxes we use is that they have a solid black panel that you can slide back to reveal the clear panel underneath - so you can get a good look in the nestbox without disturbing the female.

You'll have already decided whether you want to do maternal or artificial incubation - make sure you have everything ready and running a week in advance of eggs. You can learn about incubation over on our egg care page.