Morelia viridis, commonly known as the green tree python, or as it is known in the herpetoculture hobby, chondro (due to its former classification in the genus Chondropython) is a species of python found in New Guinea, islands in Indonesia, and Cape York Peninsula in Australia. The green tree python is characterized by a relatively slim body. The relatively long tail accounts for about 14% of the total length. The head is large and clearly defined from the neck. The snout is large and angular. The body is triangular in cross section with a visible spine. The species usually reaches a total length of 150–180 cm (4.9–5.9 ft), but large females may reach 200 cm (6.6 ft). The size also varies depending on the region of origin. The weight is highly dependent upon the nutritional status of the animal. Males can weigh about 1,100–1,400 g (2.4–3.1 lb), females up to 1,600 g (3.5 lb), although wild specimens are typically much lighter than this. Especially large specimens that can weigh up to 2,200 g (4.9 lb) are invariably females, which like most snakes are slightly larger and heavier than males.
Green Tree Pythons are found in Indonesia (Misool, Salawati, Aru Islands, Schouten Islands, most of Western New Guinea), Papua New Guinea (including nearby islands from sea level to 1,800 m elevation, Normanby Island and the d'Entrecasteaux Islands) and Australia (Queensland along the east coast of the Cape York Peninsula). This species is sympatric with M. spilota and the two often compete in the same ecological niche. Its main habitat is typically in or near rainforest, and is primarily arboreal, residing in trees, shrubs and bushes. Occasionally it is seen on the ground. In the wild, The Green Tree Python's diet consists mostly of small mammals, such as rodents, and sometimes reptiles. This snake, like the Emerald Tree Boa, was thought to eat birds. However, Switak conducted field work on this issue. In examining stomach contents of more than 1,000 animals, he did not find any evidence of avian prey. Prey is captured by holding onto a branch using the prehensile tail and striking out from an s-shaped position and constricting the prey. Wild specimens have also been observed and photographed wrapped around the base of small tree trunks, facing down in an ambush position, presumably waiting for ground mammals to prey upon.
Green Tree Pythons are often bred and kept in captivity, although they are usually considered an advanced species due to their specific care requirements; once these are met, they usually thrive in captivity. Most green tree pythons can be expected to live into their mid-teens with good care. A few have even made it into their mid-20s. Juveniles can be shy, so it’s best to start them off in smaller enclosures measuring 1 foot (length) x 1 foot (width) and 1 foot (height). Adult green tree pythons make full use of the larger sizes, such as 2 feet (length) x 2 feet (width) x 2 feet (height) enclosures or 3 feet (length) x 2 feet (width) x 2 feet (height) enclosures.
The Green Tree python is oviparous, laying 1–25 viable eggs per clutch. Breeding has never been reported from the wild, however in captivity eggs are incubated and protected by the female. Hatchlings are lemon-yellow with broken stripes and spots of purple and brown, or golden or orange-red. For yellow individuals at Iron Range National Park, Australia, the color change occurred over 5–10 days when individuals were 58–60 cm (23–23.5 in) long, which corresponds to about a year old. Color change for red juveniles has not been observed in the wild. Female green tree pythons need to be at least 3½ years old and at least 2 pounds; male green tree pythons sometimes are willing to breed when 2½ to 3 years old. Candidates for breeding should be healthy and well-conditioned with good body weight and muscle tone. The reproductive season begins with thermal cycling. Drop the nighttime cage temperatures into the upper 60 degrees Fahrenheit. Begin with a gradual drop, and work down to about 68 degrees. It is important to return cages to normal average daytime temperatures of 84 to 86 degrees throughout the cycling period. Green tree pythons normally copulate for four to six weeks. If all goes well, the female begins to swell with developing egg follicles, and the male loses interest in her. She begins to refuse food at this time. Four to six weeks after going off-feed, the female ovulates. This is marked by a 48-hour swelling and restless posturing. Females have a pre-lay shed about 25 days after ovulation and 14 to 21 days before egg deposition. Female green tree pythons should be given a dry nestbox in which to lay eggs. You can allow the female to brood her eggs, but most breeders these days use artificial incubation to hatch eggs. This allows a much faster recovery for the postpartum female. Clutch sizes range from 10 to 30 eggs, but 20 is about average. Incubated at approximately 87 to 88 degrees, eggs take about 50 days to hatch.