Morelia spilota variegata
Scientific Name: Morelia spilota variegata
Common Names: Darwin Carpet Python, Northwestern Carpet Python
Taxonomy
Morelia spilota variegata is a member of the Pythonidae family and a subspecies of Morelia spilota.
The classification of Morelia spilota variegata has seen several changes over the years, reflecting an evolving understanding of its taxonomy.
Initially, in 1842, Gray broadly applied the name Morelia variegata to all carpet pythons.
In 1981, Gow distinguished the centralian carpet python, Morelia bredli, from variegata. This was followed by Smith the same year, who further refined the classification by separating the southwestern carpet python, Morelia imbricata, from the broader variegata group.
Wells and Wellington in 1984 described several taxa previously grouped under variegata, refining Morelia spilota variegata’s status as a distinct subspecies.
In 2000, Hoser solidified the classification by isolating the New Guinea population and narrowing the focus to describe only the populations along the northern coast of Australia, including the Northern Territory and parts of Western Australia.
The species was officially named as we know it today in 2003, thanks to the contribution of Franz.
Description
Morelia spilota variegata, commonly known as the Darwin Carpet Python or Northwestern Carpet Python, is a medium sized python, native to northern Australia, particularly the Northern Territory, and parts of Western Australia.
In my experience, adults typical reach around 2 meters (6’6”) in captivity, but individuals around 3 meters (9’9”) have been observed both in captivity and in the wild. It all comes down to age, and even more so, feeding regime.
I have measured a 7 year old pair, where the female weighted 1418 g (3.12 lbs), 3 months after laying eggs, and measured 190 cm (6’2”). The male weighed 1342 g (2.95 lbs) and measured 186 cm (6’1”). Both on empty stomachs.
Their appearance can vary significantly, but they typically exhibit a striking coloration. The saddles are often in a rich red or brownish hue, reminiscent of rust, with a lighter shade along the belly. This color gradually darkens towards the back, culminating in a deep black in some individuals. They have gray to light yellow tiger stripes with a black stroke.
The albino mutation is a rainbow of yellow to orange nuances. The red saddles are replaced by orange ones, and the tiger stripes are light yellow with a white stroke. Their belly and head pattern have an acidic green color to them. Something that’s very characteristic of pure albino Darwins. They can change saturation from bright yellow, white and acid green to faded yellow and orange depending on the lighting.
Like other carpet pythons, they have a calm demeanor and are easy to handle, especially when out of their enclosure. However, their feeding response is highly reactive. When you open their cage at night, they may rapidly strike at anything that moves, showcasing their innate ambush predatory behavior.
As a sedentary arboreal subspecies, they often remain in the same refuge sites, such as trees or buildings, for extended periods—sometimes over two months. They can stay in the same area for up to 300 days, moving only 190 m (623’) between sites, and spending just 7% of their time on the ground traveling between these locations (Bedford, 2003).
This arboreal tendency is also evident in captivity, where they are extremely active at night, climbing if given the opportunity. Something I have not experienced to this extent in other subspecies of carpet pythons.
In the wild, Morelia spilota variegata has a diverse diet that primarily includes amphibians, mammals, birds, and occasionally reptiles. Young individuals primarily feed on birds, gradually moving on to mice, possums, bats and occasionally cats as they grow. This varied diet supports their adaptability to different environments, from forests to suburban areas. Their ambush hunting strategy allows them to capture unsuspecting prey effectively, often striking from a concealed position.
Distribution
Morelia spilota variegata is primarily found in the northern regions of Australia, including the Northern Territory and parts of Western Australia. Their range encompasses diverse habitats such as sandstone landscapes, gorges, vine forests, wooded savannas, gallery forests, and sclerophyll forests. These pythons are highly adaptable and thrive in both humid and dry conditions.
They are often located near water sources such as rivers and wetlands, which support a rich variety of prey. Additionally, they inhabit areas with rocky outcrops and dry woodlands, demonstrating their ability to occupy a wide array of ecological niches. This adaptability to various environments highlights their ecological versatility and resilience, allowing them to maintain a crucial role in the ecosystems they inhabit and contributing significantly to maintaining ecological balance across their range.
Captive Care
Carpet pythons, in general, are very easy to care for and thrive well in captivity, making them ideal for both beginners and experienced keepers. While some hatchlings can be nervous and may strike when handled, they typically calm down with regular interaction. As they mature, they tend to outgrow this behavior and become quite docile. Adult carpet pythons are usually easy to handle and display a calm demeanor.
Cage Size
An enclosure of at least 120x60x60 cm (4’x2’x2’) is recommended for adults. Vertical space for climbing is beneficial, as these pythons enjoy exploring their surroundings and are fairly active at night.
Substrate
Allspan Super, hemp bedding, coconut husk, or cypress mulch all work perfectly well. I prefer Allspan Super myself as it never molds and is super easy to spot clean.
Humidity
Carpet pythons are very forgiving when it comes to humidity and typically do not have problems shedding. I maintain around 50% humidity.
Heating
I provide a heat spot of around 29-30°C (84-86°F) and keep the cool end of their enclosure at around 26°C (78.8°F).
Cycle
I keep light and heat on for 10 hours a day year-round. Nighttime temperatures depend on seasonal fluctuations and can go as low as 19°C (66.2°F) on the coldest nights during winter.
I offer my animals a cooling period from the end of November to the start of March. During this time, they experience colder nighttime temperatures and are completely without food.
Feeding
Carpet pythons are enthusiastic feeders and will prey on appropriately sized rodents and birds. I start hatchlings on mouse fuzzies or rat pinkies and switch to larger mice and eventually rats as they mature.
Most reptiles in captivity are unfortunately obese, and overweight snakes have become the norm. As a result, it can be challenging for new keepers to recognize what a healthy carpet python looks like. When viewed from above, you should see muscles on each side of the backbone, which itself should appear slightly sunken. This contrasts with a round back that lacks definition and tone. The tail, from the cloaca to the tip, should look square and flat rather than resembling a round, elongated balloon. The head should be large and square, tapering into a thin neck. In summary, the ideal condition of a carpet python resembles a Toblerone bar rather than a Coke bottle.
Obesity in carpet pythons, and reptiles in general, is the leading cause of cancer. Additionally, even a small amount of excess fat can accumulate around organs, leading to issues such as fatty liver disease and fatty heart disease.
Overweight males are less likely to impregnate females, while overweight gravid females are more likely to experience complications during egg-laying, such as egg binding (inability to lay eggs) or laying infertile eggs (slugs).
Because carpet pythons have a strong feeding response and are kept in enclosures where they do not get the same amount of exercise as in the wild, it is very easy to overfeed them. Like humans, a sedentary lifestyle combined with consuming more calories than are burned will cause overweight.
Following a strict feeding regime is crucial for a long and healthy life for your carpet python. Hatchlings can be fed weekly, while carpet pythons ready to move to new owners should be fed every 1-2 weeks. As yearlings, you can continue feeding bi-weekly, gradually extending the time between meals to three weeks as they near two years of age. When they reach three years, feed them every four weeks, and from four years onward, they should be fed around seven times a year.
Cycling carpet pythons and cooling them for 3-4 months a year without food gives their metabolism and overall system a much-needed break.
Breeding
Breeding carpet pythons is relatively simple, but for the best continuous results, you need to cycle them.
I live in Denmark, where winter occurs from December to February, making these the coldest months. Therefore, it makes sense to plan my cooling period during these months. If you experience winter at a different time of the year, adjust accordingly.
I ensure the ambient temperature at night drops to around 19°C (66°F). This is weather-dependent, but it’s my target temperature for the coldest nights. I achieve this by using smart thermostats for ambient heat, the automatically drop at night, and increase in the morning.
If you have trouble breeding carpet pythons, it’s often because they are kept too warm. I’ve found that some individuals breed well even at warmer temperatures, whereas others need to experience these colder conditions.
In mid-November, I feed my carpet pythons their last meal of the season, allowing them to defecate before entering the breeding season.
In early to mid-December, I introduce males to females by moving them into the females’ enclosures. I let the males stay for 1-2 weeks, then give them a few days’ break before reintroducing them to the females.
If we experience nights with heavy snow or strong winds, I ensure the males are with the females, as the low atmospheric pressure triggers breeding responses in the snakes.
I continue introducing the males to the females until I’m certain the female is gravid (she looks large and round in the last third of her body). This usually occurs around February. In February or March, the female will shed, which is called the pre-lay shed, indicating she is about to lay her eggs. The eggs are usually laid 30-60 days after the pre-lay shed. 30-40 days is most common, but some females may take longer, which is normal.
After the female has laid her eggs, I place them in an incubation box and then in the incubator. I use plastic boxes with a grid in the middle. Beneath the grid, I have tap water, and I lay the eggs on the grid. The box is sealed with a lid, which has four small holes, one in each corner.
I incubate the eggs at around 31°C (88°F), maintaining as constant a temperature as possible. After about 60 days, the eggs will start to hatch. About a week before hatching, the eggs will begin to dent, indicating the hatch time is near.
I remove the hatchlings as soon as they are fully hatched and place them in separate boxes with a misted paper towel, and place the boxes in a hatchling rack. I provide the hatchlings with a heat spot of around 28-30°C (82-86°F), turned on for 10 hours a day like the adults, and completely off at night.
Typically, after about a month, the hatchlings will shed, and I will attempt to feed them with a fuzzy mouse or rat pinky. If most of the clutch has shed but some individuals haven’t, I will try to feed them before they shed, and they usually take the food and shed faster.
Projects
Albino
The albino mutation in Darwin carpet pythons, characterized by a lack of dark pigments resulting in vibrant yellow and white coloration, was first identified in wild populations during the 1980s. This discovery sparked interest among Australian reptile enthusiasts, who began breeding these striking snakes in captivity.
The 1990s saw the first significant efforts to breed albino Darwin carpet pythons in captivity. Despite their growing popularity within Australia, strict wildlife export laws prevented these reptiles from being legally exported.
However, some albino Darwin carpet pythons were smuggled out of Australia during this period, finding their way into the hands of international breeders in the United States and Europe. These illegal exports, although controversial, facilitated the introduction of the albino Darwin carpet python to the global reptile hobby. Breeders outside Australia began to work with these pythons, increasing their numbers and refining their genetic lines through selective breeding programs.
By the early 2000s, albino Darwin carpet pythons had become well-established internationally in the reptile hobby.
The albino mutation is a recessive trait, meaning an individual must inherit two copies of the albino allele (one from each parent) to express the albino phenotype.
Tiger Darwin
The term “Tiger Darwin” refers to Darwin carpet pythons with a stripe running down their back. I began my breeding project with two individuals, one of which had a 10 cm (4”) stripe. Breeding these two snakes resulted in a female with about 50% striping. Through further selective breeding, I successfully produced a fully striped male in 2024.
The more striped individuals you breed together, the more defined and consistent the stripes and reduced patterns will become. I’m excited about the future, as I aim to produce such striped animals consistently.
The striping is polygenic, meaning it is influenced by multiple genes rather than a single gene mutation. Unlike simple recessive or incomplete dominant traits, polygenic traits result from the combined effect of several genes, each contributing to the overall phenotype. This leads to a gradient of expression rather than an all-or-nothing outcome.
Breeding for polygenic traits involves selecting individuals that exhibit the desired level of striping and pairing them. Over multiple generations, you can enhance the striping by consistently selecting and breeding individuals with more pronounced patterns. However, due to the polygenic nature of the trait, there is always some level of unpredictability in the outcomes.
Conservation Status
IUCN Red List: Least concern
CITES: Appendix II
Status: Carpet pythons (Morelia spilota) are protected under Australia’s Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), which regulates the international trade of these reptiles to prevent exploitation. This law ensures that carpet pythons cannot be captured or exported without proper authorization, protecting them from illegal trade and harm.
Despite being listed as “Least Concern” on the IUCN Red List, indicating a stable population in the wild, these protections are crucial in mitigating threats such as habitat destruction and illegal poaching. The EPBC Act provides a comprehensive framework for the conservation of carpet pythons, ensuring their populations remain stable and their ecological roles within Australian habitats are preserved.
Gallery
Written by Paul Sørensen DKPythons