Reptiles
Green Tree Python
Morelia viridis · also called green tree python, GTP, chondro
The green tree python is the snake on every rainforest poster — vivid emerald, looped in tidy saddles over a branch with its head hanging in the middle. Its babies hatch canary-yellow or brick-red and only turn green as they grow, and a near-identical snake, the emerald tree boa, evolved the same look independently in the Amazon.
Overview
Green tree pythons live in lowland and hill rainforest of New Guinea, the eastern Indonesian islands, and the tip of Cape York in Australia. They are arboreal ambush hunters of rodents, lizards, and birds, with a slender prehensile body, a big head, and heat-sensing pits along the lips that let them strike accurately in the dark.
The coil
By day the python rests looped over a horizontal branch with its head lowered in the centre of the coils, and it strikes downward at prey passing below. The pose is so distinctive it is the first thing keepers learn to recognise.
Yellow to green
Hatchlings are lemon-yellow or, in some populations, red-brown, changing to adult green over 6–12 months. The reason is debated — likely camouflage in the sunlit shrub layer where juveniles hunt reptiles, versus the shaded canopy where adults ambush mammals.
An evolutionary twin
The green tree python and the South American emerald tree boa look and behave almost identically despite being only distantly related — one of the clearest cases of convergent evolution in reptiles. The python lays eggs; the boa bears live young.
Status
The green tree python is Least Concern and widespread, but heavily collected for the pet trade, with wild-caught snakes often sold as captive-bred.
Green Tree Python: common questions
Are green tree pythons venomous or dangerous?
No, they are non-venomous constrictors and pose no danger to humans beyond a painful bite. A green tree python kills prey by striking, holding on with many long recurved teeth, and throwing coils around the animal to stop its breathing. Because those teeth are unusually long — an adaptation for gripping birds and mammals through feathers and fur from an awkward downward angle — a defensive bite can bleed and should be cleaned, but there is no toxin involved. The species has a reputation among keepers for being nippy, especially as juveniles and at night when they are hunting, so it is generally kept as a display animal rather than one to handle often.
Why are baby green tree pythons yellow or red instead of green?
Green tree pythons undergo an ontogenetic colour change — they hatch bright yellow, or in certain populations a deep brick red or maroon, and shift to the adult green over roughly six months to a year. The function is not settled. One idea is that the juvenile colours camouflage the small snakes where they actually spend their first months — hunting reptiles at the sunlit forest edge and in low shrubs, where yellow and red blend with dead leaves and dappled light — while adult green suits the shaded mid-canopy where they later ambush mammals. Another possibility is that the bright juvenile colour warns off predators or signals to other pythons. Yellow and red juveniles from different regions turn green by different routes, which is one reason the pet trade prizes particular locality lines.
How is a green tree python different from an emerald tree boa?
They are a famous example of convergent evolution — two snakes that evolved nearly the same body, colour, and behaviour independently on different continents. Both are emerald green with white or yellow markings, both drape in the same distinctive coiled-over-a-branch resting pose, both have very long front teeth and heat-sensing pits, and both are arboreal ambush hunters. But the green tree python lives in New Guinea and northern Australia and lays eggs, which the female incubates by coiling around them, while the emerald tree boa lives in the Amazon Basin and gives birth to live young. They are only distantly related within the broader snake family tree; their resemblance comes from solving the same problem — hunting warm-blooded prey from rainforest branches — in the same way.
Do green tree pythons make good pets?
They are popular with experienced keepers but are considered an intermediate-to-advanced species, not a beginner's snake. They need a tall, planted enclosure with sturdy horizontal perches, carefully controlled temperature and humidity, and good ventilation, and they are sensitive to husbandry mistakes that other pythons tolerate. They also tend to be defensive and are best handled sparingly. A serious concern is sourcing — green tree pythons are still taken from the wild in large numbers, particularly in Indonesia, and sold with false captive-bred paperwork, so buyers are encouraged to use reputable breeders with verifiable lineage. Captive-bred animals are calmer, healthier, and do not add pressure to wild populations.