The Green Tree Python (Morelia viridis) is a species of python native to New Guinea and nearby Indonesian islands, as well as northeastern Australia. It is one of the most popular python species kept as pets, due to its striking appearance and relatively manageable size.
The Green Tree Python is also known for its arboreal lifestyle, spending most of its time coiled around branches or vines in trees and shrubs, or high up in the tree canopies. The species is known for its vibrant green color, which helps it blend in with the foliage, making it a difficult animal to spot.
Green Tree Python – Characteristics
Green tree pythons are known for their beautiful and distinctive green coloration, which serves as excellent camouflage in their arboreal habitat. It also makes them an attractive species as in the pet trade too however, which can be a bit of a curse for these snakes.
They are sexually dimorphic with females growing larger than males in maturity. On average, they can grow to around 5-6 feet (150-180 cm) long, with some female specimens reaching up to 7 feet (210 cm) in length. Location is known to have an impact on how large these snakes grow and weigh, with nutritional quality playing a major role in their development.
A well nourished male can average between 1.1–1.4 kg (2.4–3.1 lbs) and this increases to 1.6 kg (3.5 lbs) for females. In rare examples a female can reach up to 2.2 kg, but sizes this large are usually reserved for captive individuals.
In terms of appearance, the green tree python has a slender body with clear definition between the head and the neck. The spine is clearly visible down the triangular body and they have a large angular snout. They look similar, and have similar behavioural traits to the emerald tree boa (Corallus caninus) from South America. Though these snakes are actually very different and not members of the same family.
In their natural habitat, Green Tree Pythons have a species defining habit of resting in a very particular way in the trees. They wrap themselves around into two or three coils, and place their head in the middle, while resting on a horizontal branch of a tree. They take on this posture when resting, but when hunting they wrap their tail around the branch, while coiled like an accordion, ready to strike at any passing prey on a branch or the ground.
The green tree python is also known for being the most arboreal of all pythons, only rarely ever coming to ground. They are one of the rare examples of a species that changes their circadian rhythm as they mature. As juveniles they are diurnal, but as they mature they both change their color and become nocturnal animals.
Despite the notoriety, pythons including the green tree python are non-venomous snakes. They are solitary outside of mating season and not very active until hunting or mating.
Location & Habitat
In the wild, green tree pythons are found specifically in New Guinea, some of the Indonesian islands including Salawati, the Aru Islands, the Schouten Islands and the Cape York Peninsula region of Australia.
They inhabit lowland and submontane rainforests, as well as secondary forests, swamps and savannas. Green Tree Pythons are arboreal, which means they live in trees and dense shrubbery, bushes or vines. They prefer dense vegetation, where they can hide and hunt for their prey. They are rarely seen on the ground but it’s not unheard of, and are never far from the forest.
Most of what we know about the reproduction of green tree pythons is from information collected by captive breeders and zoos. There is no recorded data as yet for reproductive behaviour in the wild.
From what we do know, females lay their clutch of eggs around October, which may include anywhere from 6 to 32 eggs. The eggs then have a gestation period of between 39-65 days, but average around 50 days. When the snakes hatch, they are usually around 30 cm long, and have a yellow to gold or dark red color. They don’t get their adult color until they are generally double in size.
Males mature faster than females, with sexual maturity reaching males in around 2.5 years, while it’s up to 3.5 years for females.
Information on actual lifespan in the wild is limited. However, it is believed that these pythons could live an average of 15-16 years in the wild, with a maximum age of 19. In captivity, green tree pythons have been observed to reach up to a little over 20.5 years.
Green tree pythons are not born green, and don’t take on the bright color they are known for until they reach around 12 months old. When they hatch, and for the first few months they have a variety of bold colors from rust red or purple, to bright yellow or golden. In observations the color change to green is not a slow process, but tends to take place over around 10 days, once they have reached around 58–60 cm long.
These tree dwellers are carnivorous, and live mostly on a diet of small mammals and reptiles. They are ambush predators and nocturnal, hunt mostly at night. They patiently lay in wait, wrapped around branches for prey to pass by. They can detect warm blooded prey in their vicinity by making use of temperature sensing pits near their noses. The colder nights make this more effective, as their is a greater difference between ambient temperature and the temperature of their prey.
Juveniles are known to lure their prey in, particularly small mammals, by using the tip of their tail. At this stage of life they are diurnal. As hatchlings, their main prey are some species of skink, and small diurnal invertebrates. Once they are a little older them move on to small lizards and larger invertebrates.
It is as adults that they move onto a diet mostly of small mammals and birds, and turn into nocturnal hunters. Specific prey species vary depending on their local habitat. For example, in one area of Australia, the Cape York Rat is a major prey species. Rodents such as mice, and some frogs make up a good part of their diet. They don’t need to feed often, and are known to use the same ambush site for up to 14 days.
Green tree pythons have quite a few natural predators in their native habitat. Despite their ability to camouflage in the trees. Some of their most common predators from above include black butcherbirds, some diurnal raptors and rufous owls. In Australia, dingoes are a threat to snakes close to the ground and in New Guinea, quolls and mangrove monitor lizards are also a prominent predator.
Their main method of defence, particularly from aerial threats, is to camouflage within the tree canopies, wrapped around branches.
Threats & Conservation Status
The green tree python is currently listed as a species of least concern on the IUCN Red List. The species has a large range and despite the threat of smuggling, populations are relatively secure. The risk of an escalating black market trade is real however, and needs to be monitored to prevent populations becoming vulnerable.
They are a popular pet species which does well in captivity and this drives the potential for illegal trade. However, up to half of those illegally traded are thought to die in the smuggling effort or in transport. TO try and protect these snakes, they are listed under appendix II of the CITES index of vulnerable species. Also in Indonesia it has been fully protected under national legislation since 1999.