tree python found two distinct lineages: a southern lineage comprising populations of Australia, the Aru Islands, and New Guinea south of the central highlands, and a northern lineage of New Guinea north of the central highlands and the Vogelkop Peninsula, and Biak Island. The two likely diverged around 5 million years ago with the rising of the central mountain range in New Guinea. The authors suggested this might explain poor breeding success in Australia if people were unknowingly trying to breed the northern and southern green tree pythons, as they were not closely related. The two taxa are indistinguishable in appearance. Description 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 (including tail) of , but large females may reach . 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 , females up to , although wild specimens are typically much lighter than this. Especially large specimens that can weigh up to are invariably females, which, like most snakes, are slightly larger and heavier than males. Distribution and habitat M. viridis is 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). The type locality given is "Aroe-eilanden" (Aru Islands, Indonesia). This species is sympatric with M. spilota and the two often compete in the same ecological niche. The preferred natural habitat of M. viridis is in or near rainforest, and the species is primarily arboreal, residing in trees, shrubs, and bushes. Occasionally, it is seen on the ground. Conservation In 2010, the green tree python was rated as least concern on the IUCN Red List of endangered species on the basis of its large range and isolated declines in population from smuggling. However, the threat from smuggling for the pet trade was recognised and requires monitoring. Behaviour Primarily arboreal, M. viridis has a particular way of resting in the