Reproductive Info:

In the wild, Retics breed from September through November.  This is basically an interim time period after the dry season is over and before the wet season begins.  Like all Pythons, Retics are Oviparous.  They lay their eggs and then brood them.  Incubation lasts approximately 87 days at a temperature of 90 degrees Fahrenheit.  

In captivity, Retics breed readily regardless of season.  Retics have been hatched out in every month of the year.  Males can easily fertilize multiple females.  Males will combat other males fiercely, and should be kept separate.  Males will be sexually mature sometime between the ages of 12 and 18 months at a length of about 9 or 10 feet.  Females are mature at approximately 2 ½ to 3 years of age and at a length of about 13 feet.  The larger your female is, the better, without being obese.  An obese Retic, male or female, will likely not be a good breeder.

In captive Python propagation as a whole, it is somewhat standard to cycle the animals you wish to breed.  In the fall you would begin to drop the ambient nighttime temperatures as well as shorten the daytime light period.  This will cause the female to become “ready” to breed and she will then begin refusing food.  With few exceptions if a female Retic is still eating, she will show no interest in breeding.  And if she’s not interested in breeding than it’s not going to happen.  For one thing the female is typically much larger than the male.  For another, if she is not ready than she won’t release any of the proper pheromones, which attract the male, so he won’t even try.  This is truer of less experienced males than of more experienced males.  A very experienced male could try to breed a female that isn’t ready, but it’s still not going to happen.  When a female that is not ready to breed is presented with an adult male, she will display her displeasure immediately.  She will begin tail wagging, whipping her tail back and forth violently much like an agitated cat.  She may also start literally pushing him around with her sizable coils, slamming him into the walls of the enclosure.   Some tail wagging usually happens, even with “in season” females, so don’t get discouraged and remove your male immediately if this happens.  You will know the difference between a slight and a severe reaction, as it is obvious.  If you get a moderate adverse reaction from your female, and she is currently refusing food, it’s best to introduce the male gradually over a few days.  Leave him in with her for 15 or 20 minutes at first.  The next day, leave him in a little longer and so on, until she is more used to him.  Never put 2 animals together and leave.  You should always introduce animals when you have time to observe them for a while to make sure they will tolerate each other.  Also, if one of your animals was mis-sexed, than you could be introducing 2 males together, in which case aggressive combat will likely ensue.  

 

Some breeders find temperature and photo cycling to be unnecessary to reproduce Retics.  In this case, the female will eventually stop feeding on her own for some unknown reason and will be ready to accept a male.  Sometimes simply introducing a male for short periods, several times over a few weeks will cause the female to become ready.  Males tend to always be ready to breed if in the company of an “in season” female.  The male’s only need seems to be that he can smell her pheromones.  In any case, the female should have a basking spot in her enclosure of 90-95 degrees F.  Eggs really shouldn’t experience temperatures over 91 degrees F, but a basking spot slightly warmer than 91 could be necessary to transfer the heat through the females sizable mass in order to affect the eggs.

It is best to move the male to the female’s enclosure.  He will than begin to tongue flick her all over, investigating the female.  He will also move the lower quarter of his body on top of hers, perhaps even loosely wrapping his tail around her.  He will than start using his spurs.  The males use their spurs to stimulate the female during courtship.  We have found that the male’s will move all over the female, picking at her scales with his spurs, even in places no where near her vent.   Eventually he will feel comfortable enough to insert one of his hemi-penes.  Actual copulation can take place for minutes or hours.  Some pairs will breed seemingly non-stop during all hours of the day for weeks, while others will only breed periodically and at night.  We have collected successful clutches from pairs with which we never actually observed copulations.  Some are shy and some are not, much like with feeding.

If you wish to breed your male to multiple females, you can move him with any schedule that you like, as many have worked successfully.  Some choose to leave a male with each female for 5 or 6 days, while others move the male every day or every other day as long as he’s not actively breeding the female.  We believe that once you have moved the male several times, and he has been with each of several females, the females will smell each other on him, assume he is a more desirable mate and accept him more readily.   It is a good idea to separate everyone and offer food a couple times per month.  Females will almost never accept, while males may or may not.  Males will accept food during breeding season more readily if you are able to house them in a cage in a room other than the room with your “in-season” females.  If he can smell them, than he will be less likely to eat.  Males that do eat periodically during the breeding season will be able to breed more females successfully as well as maintain a more healthy body weight.

When ovulation happens, a mid-body swelling occurs in the female and lasts only a day or 2.  Once the female ovulates, it is no longer necessary to keep your male with her.  If you do not observe the ovulation than it is probably best to assume it hasn’t occurred yet, and continue to introduce your male.  Since females are typically large, it is very easy to miss ovulation.  

Typically females will begin to lay on their backs or sides at some point once gravid.  This is almost always a sure sign of pregnancy.  She will continue to refuse food in most cases, and spend most of her time basking in her hot spot.  She will shed, typically X days before her lay date.  On the day she is to lay her eggs she will become very restless and start exploring her cage.  Once she finds a suitable spot, she will lay her eggs.  A female never looks as bright and beautiful as when she has just laid eggs.  During egg laying, the female’s are usually in a sort of trance, basically unphased by the outside world.  We have literally come nose to nose with females that were laying, taken pictures, and than proceeded to take each egg as she laid it, all with out her so much as moving.  Unfortunately this has not been true 100% of the time, but it is common.  If at all possible it is best to take the eggs sooner rather than later if you’ve chosen to incubate them yourself in an incubator.  There is only a small window of opportunity to separate the eggs and put them in egg boxes before they harden and stick together.  A mass of 35 or 40 retic eggs all adhered into a giant pile would not fit easily into a typical incubator, and separating them can easily cause damage if any are torn, which they easily are.

Once she is finished, and you’ve taken the eggs that are accessible, it is time to remove the female.  Some allow you to grab them off easily believe it or not, while others fight with the veracity that nightmares are made of.  It is best to do this with a partner.  One of you should grab her head and secure her gently, but firmly behind her head, while the other works on removing her body from the pile, all while trying not to disturb the eggs too much.  The eggs are tougher and less fragile than you might think, but it’s still best not to roll them or bump or drop them. We typically put our females in a large trashcan with air holes punched in the lid.  

Now your chief concern is the eggs.  At this point, leave the eggs temporarily and mix your vermiculite, or do it before you remove the female and have it ready.  As Ralph Davis says, “Mix your vermiculite until you can clump it together like a snowball with your hands”.  We just keep adding water with a cup, and mixing it with our clean hands until the water is mixed evenly throughout the vermiculite, and you are able to clump it together in a ball.  If you are unsure of your mixture you should probably mix it too dry rather than too wet.  Both are a problem, but you can always remix and add water, or increase the humidity.  You can’t remove water from your mixture, and once eggs get wet it’s hard to fight the fungal infections.  We keep the humidity in our incubator at approximately 70%.  Eggs really shouldn’t collapse at all until they are pretty close to hatching.  If your eggs collapse prematurely, than they are likely too dry.  You may want to carefully remove them and add more water to the mixture and remix it, and/or increase the humidity as well.

Now that your egg boxes are ready with freshly mixed vermiculite, it’s time to put in the eggs.  Each egg has a space for air inside it at the very top, so it’s best not to roll or rotate the eggs too much.  Some people take a crayon and mark the top of the egg, so they always know which part should be up above the vermiculite mixture.  

You can “candle” your eggs to verify that they are indeed viable.  You simply take a small flash light and hold it firmly against the egg.  Turn all other lights off and the inside of the egg will be illuminated.  A network of red veins should be visible.  If the veins are visible, than the egg is likely viable, if you’re unsure, than incubate it anyway.  If it is a bad egg, than it will be obvious in a matter of days, as it will shrivel up and become grossly discolored.  The eggs should be stark white and fairly uniform in appearance.  

Bury your eggs about half way in the vermiculite, and space them so they are not touching.  If one egg gets a fungal infection, you don’t want it to spread to the other good eggs.  Some people poke a couple holes in their egg boxes for gas exchange, but we do not.  We know that our boxes are not airtight for one thing, and we also know that we will probably be opening the boxes once a week to check on them, which will bring in some fresh air.  You don’t want to open the boxes too often because hopefully conditions are near perfect inside and you don’t want to disrupt the air temperature or humidity once you have gotten it constant.  However, you don’t want to ignore them, because if they’re too dry you will need to remedy the situation.  Like everything else, it’s a balance.  

Now you will put your egg boxes in the incubator, and have a thermometer’s temperature probe in each box, so you can monitor temperature without opening the incubator.  Close the door and begin the long wait.  

You could choose to let the female incubate the eggs herself.  If you do, try to keep the ambient temperature around 91F.  And try to keep the humidity around 70%.  Of course Retics have been doing it the wild for quite some time, but they also don’t have 100% hatch rates in the wild.  There are a few good reasons to incubate your eggs artificially.  The most important is that your female won’t start eating again until the babies are hatched and she can no longer smell them.  For Retics this is an extra 3 months without food for your female.  Also, it is just common sense that the eggs are safer and more likely to hatch in a controlled environment.

Now that your eggs are safely in your incubator, you can give your attention back to your female.  We like to soak our females in the trashcan, with some slightly soapy warm water.  It seems to calm them down as well as removes some of the egg’s scent from her coils.  While she is soaking, we remove all of the substrate from her cage, clean the cage thoroughly and put fresh substrate in.   We rinse the soapy water off of our female and place her back in her enclosure.  Some females will not eat again until after their next shed, but some will.  Most will not eat if they can still smell their eggs.  

After the long wait is over, the young Retics will begin to slit their eggs open from inside using their egg tooth.  They will not come out right away, as they feel more comfortable and safe inside.  It is best to let them emerge on their own.  Once out, we set them up in a Tupperware container with moist paper towels for substrate.  This will help them rid themselves of the other contents of the egg that is now stuck to them.  They will shed approximately 10 days after hatching, after which you may begin to offer food.  We typically offer live rat pups for the first few weeks, and then switch them to thawed frozen rat pups.  Sometimes it is necessary to dip the thawed prey items in hot water, which enables the snake to utilize it’s heat pits.  Most Retics eat readily.