Southern Scrub Pythons in Captivity    by Yasser Moustafa

     The Southern Scrub Python is perhaps one of the greatest reptile predators in the world. They hold a spirit that we feel is unmatched by any other reptile in the world. This paper is hopefully going to provide helpful information in the further understanding in the care and reproduction of the captive Southern Scrub Python. It was originally written for submittal to Reptiles Magazine but we decided against it so we could share the information here.

     Several years ago, we had 80-90 snakes in our collection. It included some "high-end" Boas and Pythons but it was mostly comprised of good ol' colubrid species. Then, a few years ago, I was conversing with a longtime friend and fellow herper, Kevin Goerger. We got on the subject of these "yellow phase scrub pythons" on an old outdated price list from NERD. We began discussing how we both had wanted for a long time to try our hand at these amethystine pythons we had always heard about but had never seen. The wheels were now set in motion. We tracked down a young pair of Barneck Amethystine Pythons...whatever those were. We had no idea of what we were really getting into. But when Cheyanne and I first laid our eyes on those gems, we both realized that we had never seen anything more beautiful in the reptile world. We were awestruck. From there we sold a majority of our collection to fund the purchase of every scrub python we found available for the next few years.. Now it's 4 years later and we have hatched two clutches of little red babies and as of 2-20-03, we are awaiting the arrival of two more clutches.

     The Southern Scrub Python is a snake that can become sexually mature at 7-8 feet and as young as 2 years of age. They grow to an average of 11-13 feet with very rare specimens reaching 16 feet. Being such a lean and agile species, these pythons are adapted to be equally at home in the trees as well as on the ground and in water. They exhibit a variable background color of brown to straw yellow to olive green. On this background color is darker green and brown to nearly black scales that make up a complex maze-like pattern. They share the neck bars of their northern cousin, the Barneck. However the color of the bars tend to be lighter in Southerns. The posterior end of their bodies are usually well marked with high contrast banding while other can be nearly patternless through the tail. Overall, the Southern Scrub Python is very similar in pattern to that of the Australian Scrub Python, Morelia kinghorni. The Southern seems to look much like a hypomelanistic Australian although it must be noted that these two species are genetically and morphologically distinct.

     The Southern Scrub Python ranges from Southern New Guinea and west thru Southern Irian Jaya. At the time of this writing (2-5-03), Specimens from Aru and Kai Islands are also considered Southerns although it is expected that at least those from Aru will be reclassified. Southerns seem to be geographically separated from the northerly ranging Barneck by a huge mountain range dividing Papua New Guinea. There is a rogue northerly population of the Southern Scrub Python on the island of Biak where it seems they have been isolated from any genetic influence by their northern Barneck relatives.
     These pythons can occur in a wide variety of habitats from grassy savannahs to thick rainforest regions down to the mangrove swamps and as high as 4500 ft. above sea level. Many are encountered living in close proximity to humans, entering homes and raiding chicken coops. Otherwise they are found along rivers as well as roads and perched in trees. They even have been found hanging up high in caves, waiting for a bat or bird. In the wild, Southerns will consume a wide variety of prey from just about anything warm blooded to various lizard species. For the most part however, they are strict predators of warm blooded creatures.

     The behavior of these incredible pythons is very excting to experience firsthand. They will often perch in their branches for several days straight with their heads and anterior third pointing downward towards the floor of the cage. This position is the preferred ambush stance for the Southern Scrub Python. They will stay in this position for hours at times in hopes of an offered meal. The slightest movement in the vicinity of the python will quickly gain its' attention. From this position the scrub python could explode from the perch or wait for further stimulation to verify the movement it recognizes has a heat signature. These pythons are very well equipped with large eyes and many thermosensitive labial pits. Combine these senses with an excellent sense of smell and you have what could be the best predator in the boid world.
     In our collection, we have noticed a learned behavioral response that many of our scrub pythons have acquired. They seem to follow us around the building with curiosity and will even learn that when the cage lock gets disengaged, it is time to eat. They will learn, with as little as three repetitions, which side of the cage that food will be offered. It is primarily during feeding that an adult scrub python may be possibly dangerous should something go awry. But such is the case for most species that feed well in captivity.
     When we began investigating an approach to successfully reproduce these pythons, we looked for any climate data of their natural habitat. We looked at the variation in temps of various south Irian Jaya localities but found that the most consistent temperature info was based from Merauke, one of the most populated towns in the region. From there we decided to manipulate the temps provided to our scrubs to directly reflect the temperature variation of their native area. Here are our temperature guidelines that have worked so far.Please note that these temperatures are the body temperatures of the snakes and not the actual thermostat settings. There is a big difference.

Spring: DTH 86 NTL 78
Summer: DTH 88-90 NTL 80-81
Fall: DTH 86-88 NTL 80
Winter: DTH 82 NTL 73

     Now in the Spring, basking spots provided by overhead heating elements are only turned on for about 10 hours. In the summer, this can go up to 14 hours. In Fall, the elements are still on for 14 hours as well. But in winter, after a couple of weeks of transition down to cooler temps, the basking sources are turned off entirely and the room temps are then manipulated to provide the winter temps listed above. The winter period only last about 8-10 weeks with the transition period included. We then warm them back up to Spring temps and settings over the course of about 10 days. About three weeks into the winter cooling period, we simulate the heavy rains that these snakes typically experience by misting them several times a week. Also, this is the time we may begin to introduce pairs for breeding attempts. We try to introduce males when females have just shed but any time during this phase of the cooling period, copulation can occur. We have found that if a basking spot is provided for even a few hours a day, the males will be highly attracted to the warm spot. In turn, they tend to do away with the idea of breeding. In contrast, the females will often seem to try to stay as cool as possible and don't go anywhere near the warm spot. Basically when local heat is given at this time, males will go bask and females will be on the opposite side of the cage then nothing happens...they don't breed until the basking spot is turned back off. When breeding interest does arise, it is in the typical boid courtship behavior. In our record keeping, we watch for and note several things. In various stages, of courtship track the date of the introduction of the males to the females cages, them ales rubbing their noses along the females' body, body alignment, tail search, cloacal alignment, spurring and finally time and duration of copulation.
     The duration of actual copulation varies considerably. Sometimes it can be as short as an hour or as long as 8 hours, maybe even longer. As far as frequency of the breeding activity, our Southerns will occasionally breed two times in a 24 hour period and sometimes they will copulate only once and not do so again for 3-4 weeks. Over the past few years,it has occured more than once where we have recorded 15-20 coplulations from just one pair in a single breeding season.

     During the latter end of the cooling period, females will begin to develop follicles. As these follicles mature, the females will tend to stay as cool as possible until about a week or so before ovulation. Then they begin to start spending a few hours a day basking in the warm spot of the cage. Visually, the characteristics of the developing follicles will be a general look of fullness spread out in the posterior half of the body. If the snake looks fatter than it did when the cooling period (and subsequent fasting) began, this is follicular maturation. They will also darken in color a bit to possibly aid them in their sudden need to absorb heat. When ovulation does occur, it is quite noticeable. It is a very localized abdominal swelling that lasts 20-30 hours and can be twice the thickness of the snake.

     Once ovulation has occured, the female Southern Scrub Python will continue with basking but now will stay glued to the heat. We adjust the thermostat to allow for daytime body temps of 89-91 degrees F. We have noticed that once the gravid female reaches more then 91-92 degrees, she will leave the basking spot. At night, we have the thermostat set to bring the gravid females' body temperature down to 84-85 degrees at the coldest point of the night. We don't let them get any colder than this. Most of the time, females will have refused food since ovulation. This is typical of most boid species. At approximately 29-32 days after ovulation, the gravid mother to be will cast her pre-egglaying shed. At this point, she will be as dark as she gets. She will begin to bask in a beehive shaped coil and at times she will lay inverted from 90 to 180 degrees with their bellies facing up. Please see pic.

     In the 24-48 hours preceding egg deposition, the females will usually begin to roam the cage for varying periods of time. They also tend to bask a little more loosely coiled when they are not roaming. We provide a snug egg boxof some sort for the female to deposit the eggs. It is placed halfway between the basking source and the cool side of the cage. We have used pine shavings, Carefresh bedding, or green sphagnum moss as an egglaying substrate and have had equal success with all of them. When it gets close to egg deposition, we begin to heavily mist the enclosure to keep it humid. Please note, we do not spray the egg box at all...just the cage and cage substrate. Egglaying usually occurs during the early morning hours. Our Southerns are usually done laying by noon, usually earlier. Depending on the size of the breeding female, a small clutch or a very large one can be laid. While rare, female Southern Scrub Pythons can reproduce at 7 feet. In one documented case, a female just over 7 feet laid 4 fertile and 3 infertile eggs. Our Southerns bred at these smakller lengths but none finally ovualted until they were over 10 feet. At 10.5 feet a virgin female laid 16 fertile and 7 infertile eggs. We had another female lay 20 fertile and 5 infertile eggs at 8 yrs. of age and 13 feet in length. The fertile eggs we have gotten all weighed between 70-85 grams with an average weight of 79.4 grams. Infertile eggs are typically orange colored and are considerably smaller in size. Most of our infertile eggs were between 25-48 grams.

     Up until 2002, we had used the more typical incubation method using equal weighed parts of vermiculite and water but we have had difficulty in sustaining a constant relative humidity throughout the longer incubation period that scrub python eggs require. So in 2003, we are planning to use the "no-substrate" incubation method that has been used for years with Green Tree Pythons. This method reportedly works very well at maintaining constant humidity for the entire duration of incubation. We will see how well it works for us for our 2003 python clutches. Pictured here is our first Southern clutch we are trying with this method. Altogether, Southern Scrub Python eggs are managed just like other python eggs. The duration of incubation at temperatures of 88-89.5 degrees F is 72-80 days. About 7-14 days prior to hatching, the eggs begin to generate some amount of heat and the eggs will begin to dent in and sweat. Condensation will usually begin to form in the egg box as well. At this time, if possible, we drop the incubator temperature by 1.5-2 degrees. Our results have varied but the temperature alteration seems to keep the neonates from dying in the egg before they can pip. If we catch the clutch just beginning to hatch, we help out the babies by creating a small V shaped slit in the top of each egg that has not yet pipped.

     We begin preparing our small shoebox lidless rack unit cages a few days before their expected hatch date. Each container is furnished with a double layer of paper towels and a water dish large enough for the neontes to snugly fit in. We also include a cardboard toilet paper tube for hiding. And finally we outfit the cages with one or two small dowels placed horizontally across the long span of the boxes. They are provided with heat tape on the back underside of the container set to give an 87-88 degree basking area. The cool side is usually around 80-81 degrees. Once the babies each leave the egg entirely, they are weighed and subsequently given their own cage. The neonates can vary in size from 24-56 grams with an average of 39 grams. They can also vary in length from 19.5-24 inches in total length. Neonate Southern Scrubs are very thin skinned and will dehydrate very easily. So upon the arrival of the babies to their cages, the paper towels are promptly soaked with water to the point of almost puddling up. The soaking of the cage will aid in their transition from life in the egg and through the first few days of life. It also allows the snakes to remain moist until the drop off what is left of the umbilicus and yolk sac. Once the yolk sac has been dropped, the neonates promptly have their paper towel substrate changed out but at thispoint, they are kept drier by just pouring small amounts of water over the paper towel from time to time. Most folks think that when they see a snake with wrinkles in the skin, the snake is dehydrated and would benefit from being more moist. With Southern Scrub neonates, such is not the case. They get wrinkles, especially in the neck and head area when kept too moist. Every keeper must find that happy medium for the babies. Our neonates undergo their post-hatch sheds at 10-16 days of age usually but can take as long as 30 days. In the few days prior to this first shed, the cage is soaked again to aid in this activity. Please see the two pics here that show the same snake before its first shed and after. Once the shed has occurred, they are set up again in a dry cage with paper towels. The babies should still be misted regularly but never again kept wet. If any of the hatchlings are looking unusually skinny, then those are offered food immediately after their post-hatch shed. A couple of our babies that took nearly a month to undergo this first shed, were offered food at 3 weeks of age and they in turn ate the meals before their first shed. But if the babies still have good weight, we will typically wait to offer them their first meals for an extra week or two after shedding. In our experience, about 70% of the hatchlings will take their first offered meal. Some will take newborn pinky rats while other hold out for fuzzy mice. We haven't ever had any hatchlings that simply would not feed. In fact, none have ever gone more than 6 weeks after their first shed without eating a mouse pup or rat pinky. We have found that live food works much better than frozen/thawed or even prekilled food. We simply drop the prey item in the cage and leave them overnight if it takes that long. Initially, hatchlings are very nippy and if food is presented on tongs, they will begin to strike at the offered prey defensively without wrapping and consuming it. Leaving it in the cage seems to keep their focus on only the live prey item and its' movements. Southern Scrub Python hatchlings as a whole are very unproblematic to get started on feeding provided the rest of their environmental needs are met. Once they start to feed, they are offered food each week thereafter. Their second sheds come 4-6 weeks after their first. After this shed, our little ones are usually thriving and may never miss another meal again.

     Much like their close Australian relative, the Kinghorns Scrub Python, juvenile Southern Scrub Pythons are capable of growing at great speed. They can reach 4-6 feet in their first year by feeding them just averaged sized meals every 7-14 days. By two years, they will reach lengths of 7.5-9 feet and at this point, we scale back their meals to every 2-4 weeks. Adults 3 years or older are about 10-12 feet and can weigh 15-22 lbs.
     We do not recommend feeding them too often or too much in hopes of helping in growth rate or reproduction. In fact, fat scrubs do not make good breeders. They dump slugs or don't even ovulate.

     When Southern Scrub Pythons first shed, they have a uniform terracotta to red-orange color. Their pattern is often nearly untraceable. With each subsequent shed, they gain a little more contrast to their pattern and the red-orange background color will begin to fade to hues of browns first and later on, greenish gold. By 2 years of age, their color and pattern contrast stabilize into their adult hues.

     As far as we have been able to find, there are a few possible new Southern Scrub Python morphs on the horizon for herpetoculture. There is the patternless morph. We currently are working with 2.2 of these and only 2 other females are known to exist in captivity otherise. Also, we are working with the only known striped specimen in captivity. And recently we acquired what looked to be a hypo Southern. It is quite striking with copper and gold hues with about 90% reduction of melanin. Finally, we have hatched three specimens that have all shared a similar characteristic about them that we casually refer to as "Aztec". They are very busily patterned and have a bit more contrast to them. Quite possibly, they may not be a morph but we have 1.2 of these and plan to breed them together so in a worst case scenario we can consider this a new multi-generational project. With imports coming in every year, there is bound to be more specimens like these and probably some other new and more exciting morphs for the future of this species in the trade.

     Scrub Pythons in general have a bad reputation for being aggressive and bitey. While this is true for wild caught specimens (most of what is available on the market), captive born Scrubs can have good chances of taming down. They are much like nippy baby Jungle Carpet Pythons. Their tempers can vary. Some will calm down in a couple of months without any handling. Others will need to be held for brief periods one to two times a week. In personal communications with many current owners of our past hatchlings, about 70% reported that their Southerns were now tame and relatively trustworthy. Many of these folks purchased these as their first introduction to Scrub Pythons in general. All who have decided to add these fascinating snakes to their collection have expressed how unique and amazing they are. Give 'em a try. But captive born specimens and I guarantee that you will see exactly why we love Scrub Pythons so much.
NOTE: Please feel free to contact us via email or phone if you wish to discuss any details of this article. This article is not to be reprinted in any way without our expressed permission. We are usually accomodating if you ask first!
Taking a Chance | Physical Description | Habitat and Range | The Road to Ovulation
Captive Husbandry and Reproduction | The Expecting Mother | Egg Deposition
Egg Incubation | Neonatal Care | Growth and Feeding
Ontogenetic Color Change | Morphs? | Taming the Scrub