B
Species Profile

Boelen’s python

Simalia boeleni

Velvet-black python of the highlands
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Boelen’s python Distribution

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Endemic Species
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Found in 1 country

Closeup of Boelen's Python head

At a Glance

Wild Species
Diet Carnivore
Activity Nocturnal+
Lifespan 15 years
Weight 12 lbs
Did You Know?

Correct name is Simalia boeleni; long known as Morelia boeleni before DNA-based revisions placed it in Simalia (e.g., Reynolds et al., 2014).

Scientific Classification

Boelen's python (Simalia boeleni) is a large, non-venomous python endemic to New Guinea, notable for its dark coloration with contrasting pale/yellowish markings and for inhabiting upland/montane forest regions. It is a prized but relatively uncommon species in herpetoculture.

Kingdom
Animalia
Phylum
Chordata
Class
Reptilia
Order
Squamata
Family
Pythonidae
Genus
Simalia
Species
boeleni

Distinguishing Features

  • Large, heavy-bodied python; non-venomous constrictor
  • Dark (often black to charcoal) ground color with lighter cream/yellow patterning along the body
  • Endemic to New Guinea; often associated with higher-elevation habitats than many related pythons
  • Taxonomy note: historically placed in genus Morelia; now commonly treated as Simalia boeleni

Did You Know?

Correct name is Simalia boeleni; long known as Morelia boeleni before DNA-based revisions placed it in Simalia (e.g., Reynolds et al., 2014).

It's a true montane python-records are from New Guinea uplands/mountains (often cited around ~1,200-2,300 m elevation), unlike many lowland tropical pythons.

Adults are typically about 2-3 m total length (females usually the larger sex); it's robust but not as long as many giant pythons.

The "velvet" black coloration with contrasting pale/yellow bands/spots is one of the most distinctive looks in Pythonidae.

It is non-venomous and kills prey by constriction, like all pythons.

In captivity it is famous for preferring cooler conditions than most commonly kept pythons-reflecting its upland ecology.

Captive longevity is documented at 20+ years in well-managed collections; the true maximum lifespan (especially in the wild) is not well quantified.

Unique Adaptations

  • Dark (melanic) ground color likely aids heat absorption in cool montane environments, allowing faster warming during brief sun opportunities.
  • Muscular, deep-bodied build supports subduing relatively sturdy upland prey (small mammals and birds) and moving through dense montane vegetation.
  • Heat-sensing labial pits (a pythonid trait) enable detection of warm-blooded prey in low light-especially useful in cloud forest conditions.
  • Physiological tolerance of cooler average temperatures than many lowland pythons, reflected by husbandry observations (reduced feeding and stress at overly warm conditions).
  • Cryptic contrast patterning (pale/yellow markings on black) breaks up the outline in dappled montane forest light, aiding concealment while ambushing.

Interesting Behaviors

  • Primarily crepuscular/nocturnal activity: often becomes active at dusk/night to hunt and move between cover.
  • Ambush predation: tends to remain still along forest edges, animal trails, or near cover and strike opportunistically at passing prey.
  • Strong constrictor response: after a bite, it rapidly throws coils to restrain prey, then swallows head-first.
  • Thermoregulatory basking/positioning: in cool upland forests it uses sun patches, warm rocks, or elevated perches to gain heat, then retreats to cover.
  • Seasonal breeding behavior (best documented in captivity): increased roaming and mate-searching during cooler seasonal cycles; females typically coil and "shiver" to thermoregulate eggs during incubation (maternal brooding).

Cultural Significance

Boelen's python (Simalia boeleni) lives in New Guinea highlands and is rare. Zoos and snake keepers prize its velvet-black color and cool-climate habits. It has a scientific name change from Morelia boeleni to Simalia.

Myths & Legends

Highland New Guinea stories treat large snakes, including Boelen's python, as powerful forest beings linked to hidden places like riverbanks, sinkholes, and thick brush, so people respect and avoid them and stress give and take.

Across Melanesia, Boelen's python (Simalia boeleni) and other big snakes appear in origin and landscape stories as shaping waterways and guarding strong places, seen as omens that call for caution and proper rituals.

The species name boeleni honors "Boelen," given in the 1953 description. People tell how Simalia boeleni (Boelen's python) came from remote highland forests to museums, becoming a symbol of New Guinea's mountain wildlife.

Conservation Status

DD Data Deficient

Not enough data to assess extinction risk.

Population Unknown

Protected Under

  • Occurs within some protected-area landscapes across New Guinea's central highlands/montane forests (site-dependent; protected-area coverage varies by region).
  • National wildlife regulations apply within Indonesia (Papua/West Papua) and Papua New Guinea, but species-specific protections and enforcement levels are variable and not consistently documented in the open literature.

Life Cycle

Birth 16 hatchlings
Lifespan 15 years

Lifespan

In the Wild
10–20 years
In Captivity
15–25 years

Reproduction

Mating System Data Deficient
Social Structure Solitary
Breeding Pattern Transient
Fertilization Internal Fertilization
Birth Type Internal_fertilization

Boelen's python (Simalia boeleni) has little field data on mating. Like other pythons it mates by internal fertilization and lays eggs; females usually brood them. Adults are solitary; matings are brief, often competitive, seasonal, with no cooperative care.

Behavior & Ecology

Social None (typically solitary) Group: 1
Activity Nocturnal, Crepuscular
Diet Carnivore Rats (Rattus spp.)

Temperament

Secretive, cryptic ambush predator; tends to remain concealed in cover and rely on camouflage rather than active group defense.
Defensive responses when threatened can include tight coiling, striking, and sustained biting; individuals vary substantially (captive reports often note juveniles/subadults as more defensive than established adults).
HUBS (Pythonidae / large forest pythons): social behavior is dominated by solitary spacing, with brief reproductive interactions; variation is mainly seasonal (mate-searching) and context-dependent (defensiveness higher when cornered, lower when undisturbed).
Boelen's python (Simalia boeleni) adults usually reach about 1.8–2.5 m, sometimes near 3.0 m. Captive life span is often 15–25+ years; field data are scarce.

Communication

Hissing (air expulsion) during defensive displays; no true vocal calls.
Chemical communication via pheromones/scent trails detected with tongue-flicking and vomeronasal organ Mate location/sex recognition; typical of snakes
Tactile cues during courtship and mating (body alignment, rubbing, cloacal contact), consistent with pythonid reproductive behavior.
Visual/body-posture signaling in threat contexts Coiling posture, head elevation, S-curving prior to strike
Substrate vibration sensitivity (mechanosensory detection of approaching animals), used in threat assessment and prey detection rather than social coordination.

Habitat

Biomes:
Tropical Rainforest
Terrain:
Mountainous Hilly Plateau Valley
Elevation: 1968 ft 6 in – 7217 ft 10 in

Ecological Role

Montane forest mesopredator (upper-level predator of small vertebrates)

Regulates small-mammal populations (notably rodents) in upland/montane forest ecosystems Links trophic levels by converting small-vertebrate biomass into prey available for larger predators/scavengers when individuals die (carcass subsidy) Contributes to maintaining balanced bird and small-mammal community structure through selective predation

Diet Details

Main Prey:
Montane rodents Small-to-medium mammals Birds

Human Interaction

Domestication Status

Wild

Boelen's python (Simalia boeleni) is not domesticated. This wild, montane-forest snake from New Guinea's Central Cordillera is a non-venomous constrictor, about 1.8–2.4 m (largest females ~3.0 m). Humans meet it in uplands and in the international pet trade; many were wild-caught, though captive-breeding now helps make it more available, but it is still uncommon.

Danger Level

Moderate
  • Non-venomous but capable of painful, deep bites; teeth can cause lacerations and infection risk without proper wound care
  • Strong constrictor; while typical adult sizes (~1.8-2.4 m, occasionally larger) make fatality risk low compared with the largest pythons, improper handling of large adults can still cause significant injury
  • Defensive responses (striking/biting) are more likely during capture, transport, or improper husbandry; stress and overheating/incorrect temperatures can increase irritability
  • Zoonotic pathogens possible (e.g., Salmonella risk typical for reptiles) requiring hygiene precautions

As a Pet

Suitable as Pet

Legality: Laws for Boelen's python differ by country and state. International trade is under CITES, so export/import permits are often needed. In the U.S., some areas restrict ownership; check local rules. Sellers prefer or require captive-bred animals.

Care Level: Expert Only

Purchase Cost: $2,500 - $8,000
Lifetime Cost: $12,000 - $30,000

Economic Value

Uses:
International pet trade (high-value specialty species) Zoo/education display value Local/limited subsistence or opportunistic collection (minor compared with lowland pythons)
Products:
  • Live animals for herpetoculture (primarily captive-bred in legal markets)
  • Educational/interpretive value in zoological collections (non-consumptive)

Relationships

Predators 4

New Guinea Harpy Eagle Harpyopsis novaeguineae
Monitor lizard
Monitor lizard Varanus spp.
Quolls
Quolls Dasyurus
Humans
Humans Homo sapiens

Ecological Equivalents 4

Animals that fill a similar ecological role in their ecosystem

White-lipped python Leiopython albertisii New Guinea forest python (Leiopython) fills a similar ground-to-low-branch hunting role to Boelen's python (Simalia boeleni), ambushing or hunting small mammals and birds at night and using logs and vegetation for concealment; Boelen's favors upland/montane forests, while Leiopython occurs in lowland to hill forests.
Green tree python
Green tree python Morelia viridis A New Guinea python that inhabits trees, occurs in the same area, and eats similar prey (birds and small mammals). Used as a stand-in for a forest-dwelling, non-venomous constrictor with a similar ecological role.
Amethystine python
Amethystine python Simalia amethistina A closely related large Australo-Papuan forest python that eats birds and mammals, kills prey by constriction and swallowing, is often found at lower elevations, and may grow larger. Both are upper-level predators in forests.
Papuan python Simalia papuana Geographically proximate New Guinea Simalia that occupies forest and woodland edges and hunts similar prey (small mammals and birds). Useful ecological comparator for Papuan-region pythons with similar reproductive mode (oviparity) and generalist predation, although Boelen's python is characteristically associated with cooler upland environments.

Boelen’s python is a native of New Guinea that is still a bit of a mystery to science.

This species only lives in the highland mountains that run through central New Guinea. It is a diurnal predator that spends most of its time on the ground hunting. There are reports of a few snakes reaching 13-14 feet long, but most often it averages about eight feet long.

4 Amazing Facts About the Boelen’s Python

  • This snake experiences an ontogenic color shift. That is, it hatches one color (reddish-orange or red) and then changes to another (black) as it matures.
  • It figures in the mythology and culture of some of the tribes in New Guinea.
  • Boelen’s python inhabits such a remote area that it was only discovered by western science in 1953.
  • A single hatchling can cost over $11,000 and they’re very difficult to breed in captivity.

Where to find Boelen’s Python

You’ll find this python at elevations of 7,500 to 8,500 feet in the mid-mountain forests of New Guinea in the Jayawijaya Mountain range. Occasionally, there’s a report of one in areas anywhere from the Bird’s Head Peninsula to Goodenough Island, but the temperatures in those areas aren’t optimal for the pythons.

This species is somewhat timid and hard to observe, let alone find in the wild. The mountainous region that it calls home is remote and isolated. Any useable roads are usually maintained by private companies that mine for resources like gold and other precious metals; they’re not available to the public. Yet, the publicly accessible roads aren’t passable except with a well-equipped SUV. This, along with its newness to western science, adds up to a snake that is, in some ways, still very much a mystery and difficult to study.

Boelen’s python is a terrestrial species, most active during the day. In the wild, their diet consists of lizards, frogs, cuscus, bats, and rodents. In captivity, they will take rats, quail, and rabbits. Most of what we know about their behavior and breeding comes from herpetoculturists who keep them as pets and zoos that are working to breed them.

Scientific Name and Classification

Boelen’s python is named after K.W.J. Boelen, who helped obtain specimens of the species for scientists to study. In 1953, when it was first described, scientists classified it as Liasis boelini; in 1958 it moved to Liasis toranga; over the years, it’s been variously classified in the genera Morelia, Simalia, Liasis, and Lenhoserus, finally landing (thus far), in the Simalia genus, with the Amethystine python and a few others.

Simalia genus pythons occur in Indonesia, Papua New Guinea, and Australia. Members of this genus are generally pretty big, and there are reports of Boelen’s pythons growing up to 14 feet long.

This snake goes by several names, including black python; locals know it by blue moran, papa graun, and a few others, but that depends upon the language spoken at the time. On a large island with dozens of languages, it’s easy to see how a snake with sometimes mythical connotations can have several names.

Boelen’s Python Population and Conservation

While more research is needed, these beautiful snakes are well known to the local tribes and there are many beliefs surrounding them. The IUCN Redlist of Threatened Species considers Boelen’s python “data deficient.” There isn’t enough information on its population or rarity to make an accurate assessment.

This species is relatively unknown to science and was only discovered by the west in 1953. Boelen’s python doesn’t appear common in its native range, and a distinct lack of scientific data on its population, reproduction in the wild, diet, etc. That said, it doesn’t seem to reproduce in large numbers, so any take from the wild population can damage its numbers.

Western Guinea is part of Indonesia, and the protections offered by the government for this (and other) species are extremely limited. However, on the eastern half of the island is Papua New Guinea; it is strongly protective of its wildlife, including Boelen’s python. As a result, Papua New Guinea prohibits the export of most of its wildlife. In this, Papua New Guinea is similar to Australia.

Identifying the Boelen’s Python: Appearance and Description

Once you’ve seen a Boelen’s python, it’s unmistakable. It’s a large, muscular python with a big head and elliptical pupils; adults average about eight feet long. Mature individuals have a white to pale yellow belly color, which extends in streaks up their sides. Their backs are dark purplish- or bluish-black with a distinct iridescent, oil-slick-like sheen to their scales. Adults and juvenile snakes’ upper and lower jaws have alternating black (adults) or red (juveniles) and white to cream-colored vertical bars. Their nostrils and heat-sensing pits are large and noticeable.

Breeders and zoos are responsible for much of what we know about Boelen’s python and their breeding. Like all pythons, they lay eggs – the female will lay between 6 and 14 in a clutch, then coil around them while they develop. She protects the eggs until they hatch, about 70 days later. At that point, the babies are on their own.

Juveniles are a snake of another color. They hatch as a bright red or reddish-orange snake, then darken as they mature, becoming the striking black and white or yellow snake that we know as an adult Boelen’s python. Hatchlings measure about two feet long and reportedly have a very healthy appetite.

In captivity, Boelen’s pythons can live for 20 years and more, but no one knows how long they live in the wild. Again, we need more research to determine many aspects of their life cycle.

These snakes have distinct markings that make them easy to identify.

Pictures and Videos of the Boelen Python

Juvenile boelen's python

Hatchlings are bright red; they darken as they mature.

Boelen's Python

This species is native to New Guinea and they are protected in Papua New Guinea, but not Indonesia.

How Dangerous are Boelen’s Pythons

They’re not venomous, but Boelen’s pythons can grow rather large – about 8 feet long with some reports of individuals reaching 14 feet long. Their muscular body makes them capable of injuring a person by constriction; however, they aren’t an aggressive species.

Boelen’s Python Behavior and Humans

This reclusive snake is part of the regular diet of some tribes. Other tribes only allow their warriors to eat it, and only when getting ready for war because they believe it to be one of their gods. They believe that eating Boelen’s python before going into war may give them special powers.

The snake figures heavily in the mythology of several tribes. In one story, a god that had beautiful feathers ran from a fight. As he ran, he shed the feathers bit by bit until all that remained was a black python with iridescent scales.

On the Indonesian side of New Guinea, a vibrant pet trade exports many native animals, including Boelen’s python. One problem with this is that wild-caught snakes often do not survive captivity. Additionally, those that survive in captivity often refuse to breed. Very few breeders have managed to get these snakes to breed, and those command high prices for one hatchling, currently $11,000 and up.

The other problem is the risk of over-harvesting. Some species were driven to extinction in the wild by over-harvesting – whether for the pet trade or other purposes.

Similar Animals

  • Pygmy Pythons are the opposite of Boelen’s pythons, they’re downright dainty in comparison.
  • Woma Pythons include venomous snakes in their daily diet and are immune to most of their venom.
  • Amethystine pythons are close cousins and have an iridescent sheen reminiscent of an amethyst gemstone.
View all 453 animals that start with B

Sources

  1. Black Python | IUCN Redlist of Threatened Species / Published July 25, 2014 / Accessed June 19, 2022
  2. Simalia boeleni | Reptile Database / Accessed June 20, 2022
  3. Morelia boeleni | Encyclopedia of Life, hosted by the National Museum of Natural History / Accessed June 20, 2022
  4. Boelen's Reptile | Everything Reptiles / Accessed June 20, 2022
  5. Boelen's Python | St. Louis Zoo / Accessed June 20, 2022
  6. Conservation Genetics of Boelen's Python (M. boeleni) from New Guinea: Reduced genetic diversity and divergence of captive and wild animals; Austin, Christopher C., Marc Spataro, et al / Published May 26, 2009 / Accessed June 20, 2022
  7. Threats to Boelen's Python | Mark O'Shea / Accessed June 23, 2022
Gail Baker Nelson

About the Author

Gail Baker Nelson

Gail Baker Nelson is a writer at A-Z Animals where she focuses on reptiles and dogs. Gail has been writing for over a decade and uses her experience training her dogs and keeping toads, lizards, and snakes in her work. A resident of Texas, Gail loves working with her three dogs and caring for her cat, and pet ball python.
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Boelen’s python FAQs (Frequently Asked Questions)

No, they’re a species of nonvenomous python, cousins to reticulated pythons, ball pythons, and others.