The Green Tree Python, Morelia viridis, is a visually striking, highly arboreal snake recognized for its brilliant green coloration and unique resting posture. Its vivid appearance and tendency to coil distinctively on branches have made it an object of fascination worldwide. Understanding its geographical distribution is important because it directly influences the snake’s physical characteristics and conservation status. The species’ preference for a specific environment means its presence is a sensitive indicator of habitat health across its native range.
Defining the Native Range
The Green Tree Python’s distribution is primarily concentrated within the Australasian region. The core of its habitat is the island of New Guinea, encompassing both the independent nation of Papua New Guinea and the Indonesian provinces of West Papua and Papua. This vast island territory provides the majority of the species’ range, which is often fragmented by mountain ranges and waterways. The distribution extends significantly to several surrounding islands, contributing to remarkable regional variations.
These Indonesian islands include Misool, Salawati, the Schouten Islands, and the Aru Islands. The species also exists in a highly restricted area outside of the New Guinea landmass. This population is found on the Cape York Peninsula in Queensland, Australia, representing the southernmost limit of the species’ natural occurrence. The confinement to islands has led to distinct populations evolving in relative isolation.
Specific Habitat Requirements
The Green Tree Python is almost exclusively arboreal, spending nearly its entire life in trees and demanding a habitat with a specific vertical structure. Its environment of choice is the tropical rainforest, requiring dense vegetation that offers both camouflage and stable perching sites. The snake is found in both lowland rainforests and low montane forests, with an elevation range that can extend up to 2,000 meters.
The species relies on high humidity levels and stable, warm temperatures characteristic of these tropical environments. Ideal temperatures range from 75°F to 88°F, with high moisture preventing dehydration in the canopy. While adults primarily inhabit closed-canopy forests, younger snakes often utilize canopy gaps or forest edges where more light reaches the ground. This difference in habitat use between age groups helps explain the species’ color change as it matures.
Regional Variations and Appearance
The Green Tree Python is notable for having distinct color and pattern variations, often referred to as “locals,” which are tied directly to their geographic origin. The Biak locality, originating from the Indonesian island of the same name, is known for its tendency to be larger and often retains more yellow or blue markings into adulthood.
In contrast, the Sorong locality, found in the Vogelkop Peninsula area of West Papua, is typically smaller and exhibits a prominent blue dorsal stripe or triangular blue markings along the spine. The Aru Islands locality produces snakes with a more uniform, lighter green color, frequently accented by white speckling. The concept of ontogenetic color change is central to the species: all hatchlings are either bright yellow or brick-red, helping them blend into the lower forest understory. This dramatic transition to the adult green coloration typically begins when the snake is around 12 months old and approximately 55 centimeters long, allowing the snake to camouflage in the upper canopy it occupies as an adult.
Conservation and Legal Protections
The Green Tree Python faces pressure in its native range primarily from habitat loss due to logging and encroachment on rainforest territories. Another significant threat is the illegal collection of wild specimens to supply the international exotic pet trade. Its striking appearance makes it a highly desirable animal, leading to over-harvesting in certain areas.
To manage and monitor the international trade of the species, the Green Tree Python is listed under Appendix II of CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora). This international agreement does not prohibit trade entirely but mandates that all international movement of the species must be strictly regulated and documented. The CITES Appendix II listing ensures that trade does not threaten its long-term survival, requiring exporting countries to issue permits only after determining the trade is non-detrimental to the population.