Green tree python

Green tree pythons live in warm, wet rainforests.

They live on a big island called New Guinea, and in a small part of Australia.

Green tree pythons live mainly in rainforest with a closed canopy, the leafy roof of the forest. They are found across most of the big island of New Guinea and on islands near it, and in one small corner of Australia: the northeast of the Cape York Peninsula in Queensland.

They live from the seashore up to about 2,000 meters high. In New Guinea they are also found in forest that is growing back, and even in gardens in the countryside.

The IUCN describes a wide range through New Guinea, absent only from the Trans-Fly in the south, where eucalyptus woodland does not suit it; records from offshore islands include Biak, Supiori, Yapen, Numfor and Num (Papua Province), Batanta, Kofiau, Misool, Salawati and Waigeo (West Papua) and the Aru Islands (Maluku). In Australia it is restricted to the Iron and McIlwraith Ranges of northeastern Cape York Peninsula and nearby areas, where it appears to form three isolated populations (Natusch and Natusch 2011). It lives mainly in closed forest, also using habitat next to it, and in New Guinea has been recorded in regrowth and rural gardens; elevation 0 to 2,000 m (IUCN).

Young green tree pythons eat small lizards.

Grown-ups eat mice, rats and birds.

A green tree python is an ambush hunter: it waits very still until an animal comes close, then strikes. Young pythons eat mostly lizards, especially skinks. As they grow bigger, they switch to small mammals such as rats and mice, and birds.

A green tree python may stay at the same hunting spot for up to 14 days. It squeezes its prey in its coils and swallows it headfirst. Its jaws open wide enough to swallow prey up to three times bigger than its own head.

A nocturnal 'sit and wait' predator: juveniles feed mainly on lizards, especially skinks, and adults mainly on small mammals (IUCN, after Natusch and Lyons 2014). ADW adds birds in the adult diet, ambush sites used for up to 14 days, and, as the main prey at Iron Range on Cape York, the rodents Rattus leucopus and Melomys capensis. It is a constrictor that swallows prey headfirst and can take prey up to three times larger than its head (Oregon Zoo). Caudal luring, wiggling the tail tip to attract small animals, has been observed, especially in juveniles (ADW; Moonlit Sanctuary).

A green tree python has little holes on its lip.

They feel the warmth of animals nearby.

Along its upper lip, a green tree python has small heat-sensing pits. They let it sense the warmth of animals nearby, which helps a lot when it hunts in the dark. It also uses its eyes to find food.

Scientists think the pits may also help a python find good spots to wait for prey or to warm up, and notice predators coming.

ADW: the labial heat-sensing pits lie only within the scales of the upper lip; they allow infrared imaging, which matters for a predator that hunts mostly at night as an adult, and may also help it find ambush and warm resting sites and avoid predators. Prey is found by these pits and by sight (ADW; Moonlit Sanctuary).

It rests curled up on a branch.

Grown-ups hunt at night.

Grown-up green tree pythons are active at night. When resting, they coil up over a branch or a vine, often in a tree hollow or among plants growing on the trees. To hunt, a python holds on to its branch with the back of its body and folds the front part like an accordion, ready to strike.

Green tree pythons live in the trees, but they sometimes come down to the ground at night to hunt. They live alone.

ADW: adults are nocturnal while juveniles, before the color change, are active by day; the resting posture is coiled over a horizontal branch or vine, often sheltered in a tree hollow or in epiphytes; the hunting posture extends the front of the body in accordion folds while the rear grips the perch; females, but not males or juveniles, keep home ranges (average 6.21 ha); males search widely for mates. The IUCN notes that this arboreal snake descends to the ground to hunt at night (Wilson et al. 2006). Predators include rufous owls, black butcherbirds, daytime raptors, mangrove monitors, dingoes and New Guinea quolls (ADW).

There are many green tree pythons.

People must not take them from the wild.

They need their forests.

The green tree python is listed as least concern: it lives across a wide area and is common in most of it. But people catch many wild ones to sell as pets, even though it is against the law, and this may harm some small island populations. Many pet green tree pythons are now bred in captivity.

The biggest danger is the loss of forest, such as forest cleared for oil palm plantations in the Indonesian part of New Guinea. Green tree pythons are protected by law in Australia, Papua New Guinea and Indonesia.

Least Concern (Tallowin, Parker, O'Shea, Hoskin, Couper and Amey; Global; assessed 12 June 2017, published 2018; trend stable): widespread, abundant through most of its range and present in many protected areas. Illegal capture for the pet trade continues; it may threaten some local and island subpopulations, the Biak Island subpopulation being of highest concern, and some 'captive-bred' exports from Indonesian farms are wild-caught. Extensive captive breeding may have reduced pressure. People in New Guinea also hunt it for food. The IUCN calls the expansion of oil palm plantations in West Papua and Papua, and development there, the most significant threat. Trade is controlled under CITES Appendix II, and it has protected status in Australia, Papua New Guinea and Indonesia (IUCN).