Reticulated Python (Malayopython reticulatus): Facts and Size

Appearance

The reticulated python is long and relatively slender for a giant snake. Its smooth, glossy scales carry a complex pattern of black lines that link into a chain of irregular diamond shapes along the back, often with light centers, flanked by smaller pale-centered spots on the sides. The background color ranges from yellow and gold to tan, gray and brown, and the scales can shine with a rainbow sheen in sunlight. This intricate network is what gives the snake its name: reticulatus is Latin for “net-like”.

In a zoo enclosure the pattern looks bold, but on a forest floor scattered with leaves and shadow it breaks up the snake’s outline so well that a large python can be almost invisible. Biologists call this disruptive coloration.

The head is long and fairly narrow, usually yellowish or golden with a thin dark line running along the top from the snout to the neck and a dark stripe behind each eye. The eyes are often orange or amber. Rows of deep heat-sensing pits sit in the scales along the upper and lower lips, letting the python detect warm-bodied birds and mammals even in complete darkness. Beside the vent, both sexes have a pair of small claw-like spurs, the last visible traces of the hind legs of the snake’s ancestors.

How big do reticulated pythons get?

The reticulated python is the only living snake that regularly exceeds 6 m (20 ft), although such giants are rare. A study of more than 1,000 wild pythons harvested for the skin trade in southern Sumatra found lengths of 1.5 to 6.5 m (5 to 21 ft) and weights of 1 to 75 kg (2 to 165 lb). Females grow considerably larger and heavier than males.

The longest scientifically measured wild individual came from Balikpapan in East Kalimantan, Indonesian Borneo. It measured 6.95 m (22 ft 10 in) under anesthesia and weighed 59 kg (130 lb) after nearly three months without food. In captivity, a python named Medusa in Kansas City, Missouri, was recorded by Guinness World Records in 2011 at 7.67 m (25 ft 2 in) and 158.8 kg (350 lb). Claims of 9 m (30 ft) or longer have never been verified. For the full story of records, tall tales and island dwarfs, see how long is a reticulated python?

The green anaconda is shorter but much bulkier and heavier, so the title of “largest snake” depends on how you measure. Our list of the largest snakes compares the giants.

Habitat and range

The reticulated python has one of the widest ranges of any python. It lives from the Nicobar Islands (India) and Bangladesh through Myanmar, Thailand, Laos, Cambodia and Vietnam to Peninsular Malaysia and Singapore, and across Indonesia, including Sumatra, Borneo, Java, Sulawesi and the Lesser Sunda Islands as far east as Timor and the Moluccas. It also lives on many islands of the Philippines.

Its main habitats are tropical rainforest, woodland and the grassland next to them, nearly always near water: rivers, streams, lakes and swamps. It also adapts well to plantations, rice fields and villages, where rats are plentiful. In the early twentieth century it was reportedly common even in busy parts of Bangkok, and today it still turns up in drains and riverbanks in cities such as Singapore.

The reticulated python is an excellent swimmer and has been reported far out at sea. This ability explains how it has colonized so many small islands within its range, some of which now hold small “dwarf” forms.

Diet and hunting

The reticulated python is an ambush predator. It lies coiled and motionless beside a game trail, at the water’s edge or in a tree, often for days, and strikes when prey comes within reach. It grips with its teeth, throws coils around the animal and constricts. Each time the prey breathes out, the snake tightens a little more, and the pressure quickly stops the blood flow to the brain and heart.

Diet changes with size. Pythons up to about 3 to 4 m (10 to 13 ft) eat mainly rats and other rodents, bats and treeshrews. Larger snakes take civets, binturongs, monkeys, porcupines, wild pigs and deer, including prey of more than 60 kg (130 lb). One of the largest documented meals was a 23 kg (51 lb) sun bear, eaten by the record 6.95 m python in East Kalimantan. Near villages, pythons sometimes take chickens, goats, cats and dogs.

Like all snakes, the reticulated python swallows prey whole, head first in most cases. Its loosely connected jaws and stretchy skin let it eat animals far wider than its own head; see how snakes swallow large prey. After a big meal, a python may not need to eat again for weeks or even months.

Behavior

Reticulated pythons are mostly solitary and active mainly at night and dusk, although they also bask and hunt by day. Young pythons climb well and spend a lot of time in trees, while large adults are mostly ground-dwelling and often rest in water or under thick vegetation along riverbanks.

Like other snakes, the reticulated python senses the world largely through smell, using its forked tongue to carry scent particles to the Jacobson’s organ in the roof of its mouth, and through its heat-sensing lip pits. It feels ground vibrations through its jaw and body rather than hearing airborne sounds well.

Wild reticulated pythons usually try to escape when disturbed, but a cornered snake will hiss and strike readily. The bite is not venomous but can cause deep wounds because of the long, curved teeth, and large adults are immensely strong.

Reproduction and life cycle

Reticulated pythons lay eggs. The breeding season varies across the range, and during courtship the male strokes the female with his spurs. A female lays a clutch of about 15 to 80 eggs, usually 25 to 50, and coils around them to protect them. At about 31 to 32 °C (88 to 90 °F), the eggs take roughly 80 to 90 days to hatch. The hatchlings are at least 60 cm (2 ft) long and fully independent from the start.

Growth is fast when food is plentiful. Males can mature at about 2.5 m (8 ft) and females at about 3 m (10 ft), typically when they are three to five years old. Females in good condition may breed every year, but in poor years they may skip one or two seasons.

Reticulated pythons are also one of the snakes in which virgin birth, or parthenogenesis, has been confirmed. A female named Thelma at Louisville Zoo in Kentucky, kept apart from males for years, laid eggs in 2012 that hatched into healthy young, and genetic tests later showed they had no father.

Lifespan

How long reticulated pythons live in the wild is poorly known, because few have been followed through their whole lives. Many young pythons are eaten by predators or killed by people long before they reach full size. In captivity, the species commonly lives 20 years or more, and the longest documented individuals have lived about 30 years.

Predators and threats

Eggs and hatchlings are eaten by birds of prey, monitor lizards and small carnivores. Once a python passes about 3 m (10 ft), few animals can tackle it, although crocodiles occasionally kill even big snakes near water.

The main threat is people. The reticulated python is one of the most economically important reptiles in the world. Hundreds of thousands are harvested from the wild every year, mainly in Indonesia and Malaysia, for their skins, which are made into handbags, shoes and watch straps. The snakes are also taken for meat, traditional medicine and the pet trade. Habitat loss and road traffic kill more, and pythons found near homes are often killed on sight.

Conservation status

The reticulated python is listed as Least Concern on the IUCN Red List, in an assessment published in 2018. Its range is enormous, and it tolerates plantations, farmland and even towns, so the species as a whole is not considered at risk. Studies of the Sumatran skin trade suggest that, because the snakes grow fast and lay many eggs, the regulated harvest has so far not wiped out local populations, although close monitoring is needed.

International trade is controlled under Appendix II of CITES, which requires permits and export quotas. In 2015 the United States listed the species as injurious wildlife under the Lacey Act, banning imports, because of the risk that it could establish itself in the wild, as the Burmese python has done in Florida.

Dangers to people

The reticulated python is one of very few snakes that have killed and swallowed adult humans, and the only one for which such cases are documented with photographs and video. The first fully confirmed case was in 2017, when a farmer in West Sulawesi, Indonesia, was found inside a python about 7 m (23 ft) long. Since then several similar deaths have been reported, mostly in rural Sulawesi and Sumatra.

These events remain very rare given the millions of people who share the snake’s range, and most pythons avoid humans. The width of an adult’s shoulders is a real obstacle even for a very large snake. For a calm look at the evidence, see can a snake eat a human? If you see a large python, keep your distance and leave it alone; in an emergency, seek medical help immediately.

Name and classification

The species was first described in 1801 by the German naturalist Johann Gottlob Schneider as Boa reticulata. For most of the twentieth century it was placed in the genus Python as Python reticulatus, a name still seen in many books, zoo signs and older records.

DNA studies showed that the reticulated python is more closely related to the pythons of Australia and New Guinea than to the Burmese and African rock pythons. In 2014 scientists proposed the genus Malayopython for it and its smaller relative, the Timor python (Malayopython timoriensis), and this name is now widely used. An earlier name, Broghammerus, published in a non-peer-reviewed outlet in 2004, is generally not accepted.

Several dwarf island forms have been described as subspecies, including populations on Tanahjampea and Selayar south of Sulawesi, which reach only about 2 to 4 m (6.5 to 13 ft).