Green Tree Python (Morelia viridis)
The Green Tree Python is an arboreal python native to New Guinea, nearby Indonesian islands and the Cape York Peninsula of northern Australia.
Adults are famous for their vivid green colouration, although considerable variation occurs between localities and individuals. Hatchlings are usually yellow or red before undergoing a gradual colour change as they mature.
Green Tree Pythons require carefully managed temperatures, humidity, ventilation and arboreal enclosure design. They are best suited to experienced keepers who understand their specialised requirements.
Quick Facts
Scientific name: Morelia viridis
Common name: Green Tree Python
Family: Pythonidae
Distribution: New Guinea, surrounding Indonesian islands and northern Cape York Peninsula, Australia
Lifestyle: Arboreal
Activity: Primarily crepuscular and nocturnal, although activity varies
Adult size: Commonly approximately 1.2–1.8 m, with females generally becoming larger and heavier
Lifespan: Commonly 15–20+ years in captivity
Diet: Carnivorous
Reproduction: Oviparous (egg-laying)
Experience level: Advanced
Localities and Natural Variation
Green Tree Pythons occur across a broad geographical range.
Animals associated with different regions may vary in:
- Adult size
- Body shape
- Colouration
- Pattern
- Temperament
- Ontogenetic colour change
- Environmental requirements
Locality names commonly used in captivity do not always represent animals with completely documented ancestry.
When acquiring a locality animal, obtain reliable information about its parentage wherever possible.
Husbandry should be based on the needs of the individual rather than assumptions based solely on a locality label.
Enclosure Size
Green Tree Pythons require secure arboreal accommodation with sufficient height, width and depth for movement between multiple perches and thermal zones.
For an average adult, approximately:
90 × 60 × 90 cm
should be considered a practical starting point.
Larger accommodation is encouraged, particularly for:
- Large adult females
- Active individuals
- Animals provided with extensive climbing opportunities
- Larger locality forms
An enclosure around:
120 × 60 × 90 cm
or larger can provide considerably greater usable space for an adult.
Height is valuable, but an extremely tall and narrow enclosure is not automatically appropriate. Horizontal space is also necessary so the snake can move between thermal zones without being forced to descend directly to the floor.
Juveniles can be maintained in smaller secure enclosures while still providing appropriate perches, hides, foliage and environmental gradients.
Enclosure Security
Green Tree Pythons can exploit surprisingly small gaps.
The enclosure should have:
- Securely closing doors
- Appropriate locks
- Protected ventilation
- Secure cable openings
- Firmly attached fixtures
- Guarded heating equipment
- No accessible sharp edges
- No gaps around doors or vents
Always check doors, locks and cable openings after maintenance.
Perches
Correctly positioned perches are fundamental to Green Tree Python husbandry.
Provide several sturdy horizontal or gently angled perches at different:
- Heights
- Temperatures
- Levels of cover
- Distances from lighting
- Distances from the heat source
Perches should allow the snake to rest securely without excessive muscular effort.
A selection of diameters should be available. Many Green Tree Pythons prefer perches approximately similar to, or slightly wider than, the thickest part of their body.
Perches that are excessively thin may be uncomfortable, while extremely wide flat surfaces may not permit the characteristic resting posture.
Useful materials include:
- Secure natural branches
- Cork branches
- Smooth sealed wooden perches
- Appropriately sized removable plastic perches
All perches must safely support the snake’s full weight.
Removable perches can make cleaning, inspection and necessary movement substantially safer and less stressful.
Furnishing and Enrichment
Green Tree Pythons benefit from a structurally varied enclosure.
Provide:
- Multiple secure perches
- Dense foliage
- Visual barriers
- Cork pieces
- Elevated cover
- Shaded areas
- Dark resting locations
- Different perch textures and diameters
- Opportunities to move horizontally and vertically
Foliage should create security without completely preventing observation or airflow.
Artificial or suitable live plants may be used.
All furnishings must be securely positioned and should not create trapping points.
Substrate
Suitable substrates include:
- Coconut husk
- Cypress mulch
- Orchid bark
- Soil-based tropical mixtures
- Other safe moisture-retaining substrates
The substrate can assist with humidity management but should not be kept permanently saturated.
The objective is to provide:
- Appropriate environmental humidity
- Good ventilation
- Clean substrate
- Dry resting surfaces
- Natural humidity cycles
- Access to more humid microclimates
Stagnant air and continually waterlogged substrate can contribute to bacterial, fungal, skin and respiratory problems.
Paper-based substrate can be useful during quarantine because it allows easier monitoring of waste, parasites and regurgitation.
Temperature
Provide a clear thermal gradient that allows the snake to choose its preferred temperature.
Warm Perch and Basking Surface
Approximately:
29–31°C
Warm Ambient Area
Approximately:
26–28°C
Cool Area
Approximately:
22–25°C
Night
A modest nighttime reduction is appropriate, generally around:
21–24°C
Temperatures should be assessed at the locations the snake actually uses, particularly the surfaces of elevated perches.
Avoid maintaining the entire enclosure at a uniformly high temperature.
Prolonged excessive heat can cause:
- Dehydration
- Heat stress
- Refusal to use upper perches
- Abnormal behaviour
- Increased respiratory stress
- Serious illness or death
The snake must always be able to move away from the heat source without being forced to leave all secure cover.
Heating
Suitable heating systems may include:
- Halogen basking lamps
- Deep heat projectors
- Guarded ceramic heat emitters
- Radiant heat panels
- Appropriately designed combinations of heat sources
The best system depends on the enclosure’s construction and dimensions.
Every heat source must be controlled by an appropriate thermostat.
Heat sources positioned inside the enclosure must be securely guarded.
Use:
- Digital thermometers for ambient temperatures
- Probe thermometers positioned near important perches
- An infrared thermometer for checking surface temperatures
Thermostat probes should be positioned securely and checked regularly.
A broad usable warm area is preferable to a small, intensely heated spot.
Lighting and UVB
Provide a clear day-and-night cycle.
Approximately:
11–13 hours of daylight
with seasonal variation if desired, provides a sensible general photoperiod.
Green Tree Pythons may remain sheltered during much of the day, but they still experience daylight and changing light levels in nature.
Appropriately provided low-level UVB can form part of a high-quality captive environment.
When UVB is provided, approximately:
UVI 1–2 at the primary exposed resting or basking area
is a sensible starting target.
The snake must also have access to:
- Lower UV exposure
- Complete shade
- Dense foliage
- Dark resting locations
Do not select UVB solely according to the percentage printed on the lamp.
Actual exposure depends on:
- Lamp type
- Reflector
- Distance
- Mesh or screening
- Installation
- Lamp age
A suitable UV meter provides the most reliable method of assessing actual exposure.
Humidity
Green Tree Pythons require moderately high humidity combined with effective ventilation.
A general ambient range around:
60–80%
is a useful starting point.
Humidity can increase temporarily after misting and during the night before falling gradually as surfaces dry.
The enclosure should not remain continuously saturated or stagnant.
Successful humidity management depends on the interaction between:
- Ventilation
- Temperature
- Substrate
- Enclosure construction
- Water availability
- Misting
- Room humidity
The objective is:
Appropriate humidity + effective ventilation + dry resting surfaces
Persistent condensation, wet perches, stagnant air and waterlogged substrate indicate that adjustments may be necessary.
Digital hygrometers should be used as guides, but behaviour, shedding quality and enclosure conditions must also be assessed.
Misting and Fogging
Light misting can help create natural humidity cycles and provide drinking opportunities.
Allow surfaces to dry appropriately between misting periods.
Avoid keeping the enclosure continually wet.
Automated misting systems may be used when correctly installed, maintained and adjusted. They should not replace regular observation of the animal and enclosure.
Routine warm fogging is generally unnecessary and can create persistently wet, stagnant conditions if poorly managed.
Any misting or water system must be cleaned regularly to prevent bacterial contamination.
Humid Retreat
A humid retreat can be useful, particularly during shedding or for an animal requiring additional hydration support.
Suitable materials include:
- Moist sphagnum moss
- Moist coconut fibre
- Moist soil-based substrate
The material should be moist rather than waterlogged.
The snake must always be able to choose between more humid and drier locations.
Water and Hydration
Fresh drinking water must always be available.
Provide a stable water container that the snake can easily access.
Some Green Tree Pythons drink droplets from their body, foliage or enclosure surfaces after misting. This does not remove the need for a clean water bowl.
The water container may be positioned on the floor or securely elevated, depending on the enclosure design and the individual snake’s behaviour.
Water should be changed whenever contaminated.
Signs potentially associated with dehydration include:
- Wrinkled or folded skin
- Poor shedding
- Sunken appearance
- Thick urates
- Reduced body condition
- Abnormal inactivity
Persistent hydration problems require a complete review of humidity, temperature, ventilation, drinking opportunities and health.
Feeding
Green Tree Pythons consume a variety of vertebrate prey in nature.
Suitable captive foods include appropriately sized:
- Mice
- Rats
- Chicks or other suitable poultry
- Other nutritionally appropriate whole vertebrate prey
Frozen-thawed prey is preferred wherever practical.
Routine live feeding creates an unnecessary risk of serious injury and should be avoided.
Healthy Green Tree Pythons consuming an appropriate whole-prey diet do not normally require routine vitamin or mineral supplementation.
Feeding Frequency
A useful general starting point is:
Hatchlings: approximately every 7–10 days
Juveniles: approximately every 10–14 days
Subadults: approximately every 14–21 days
Adults: approximately every 3–4 weeks
Mature adults may require longer intervals depending on prey size, activity and body condition.
These are starting points rather than fixed schedules.
Feeding should be adjusted according to:
- Age
- Size
- Prey size
- Growth
- Activity
- Sex
- Reproductive condition
- Individual metabolism
- Body condition
Green Tree Pythons can become overweight when fed excessively.
Moderate meals at appropriate intervals are preferable to routinely offering very large prey.
Feeding Safety
Green Tree Pythons can have an extremely fast feeding response.
Use:
- Long feeding tongs
- Predictable feeding procedures
- Secure enclosure access
- Adequate lighting during maintenance
Wash hands after handling prey before interacting with the snake.
Do not place hands near the head of an animal displaying an active feeding response.
Offering prey near the snake’s normal perch is generally preferable to unnecessarily moving the animal for feeding.
Handling
Green Tree Pythons should not be regarded as routine handling snakes.
Unnecessary removal from perches can cause:
- Stress
- Defensive behaviour
- Damage to teeth
- Injury to the mouth
- Injury to the spine or tail
- Damage to delicate skin
Handling may sometimes be necessary for:
- Health examinations
- Weighing
- Veterinary treatment
- Enclosure maintenance
- Relocation
Never forcibly pull a Green Tree Python from its perch.
Encourage the snake to release its coils gradually using calm, controlled movements.
Removable perches can allow the animal to be transferred without direct restraint.
A snake hook may be useful, but it should be used carefully and should not place excessive pressure on the animal’s body.
Behaviour and Temperament
Temperament varies considerably between individuals.
Defensive behaviour may include:
- Tightening around a perch
- Drawing the head back
- Tracking movement
- Striking
- Hissing
- Attempting to retreat
Many captive-bred adults become predictable when approached calmly, but even a settled animal may defend itself when disturbed.
Green Tree Pythons often rest in a characteristic saddle-shaped coil over a horizontal perch.
They may become more active during the evening and night, exploring the enclosure or adopting a feeding posture.
A sudden change in normal perch use or behaviour can indicate a problem with:
- Temperature
- Humidity
- Security
- Health
- Reproductive condition
Shedding
Before shedding, the snake may:
- Become duller in colour
- Develop cloudy or blue eyes
- Spend more time hidden
- Reduce activity
- Refuse food
Maintain appropriate humidity and provide access to a humid retreat.
A healthy shed should normally come away largely intact.
Repeated retained shed may indicate problems involving:
- Hydration
- Humidity
- Temperature
- Ventilation
- General health
Never forcibly remove retained eye caps.
Routine forced bathing should not be necessary for a correctly maintained animal.
Cleaning
Remove waste and contaminated substrate promptly.
Regularly clean:
- Water containers
- Soiled perches
- Contaminated foliage
- Feeding areas
- Frequently contacted surfaces
Perches must be kept clean, as the snake spends much of its life in direct contact with them.
Perform deeper cleaning when required rather than completely stripping a clean enclosure according to an arbitrary schedule.
Only reptile-safe cleaning products should be used and thoroughly rinsed where necessary.
Quarantine
New Green Tree Pythons should be quarantined away from established reptiles.
During quarantine, monitor:
- Appetite
- Body weight
- Faeces
- Urates
- Shedding
- Respiration
- Perch use
- Behaviour
- External parasites
Use separate equipment wherever practical.
A veterinary faecal examination may be appropriate, particularly for imported animals or individuals with uncertain histories.
Wild-caught and farm-bred animals may carry:
- Internal parasites
- External parasites
- Dehydration
- Injuries
- Infectious disease
- Stress-related health problems
Captive-bred animals from documented sources are strongly preferable.
Common Health Concerns
Potential health problems include:
- Dehydration
- Respiratory disease
- Mouth infections
- Mites
- Internal parasites
- Retained shed
- Skin infections
- Thermal burns
- Regurgitation
- Obesity
- Reproductive complications
- Injuries caused by inappropriate handling
- Spinal or muscular problems associated with poor perching
Persistent abnormalities should be assessed by an experienced reptile veterinarian.
Respiratory Disease
Possible signs include:
- Wheezing
- Clicking
- Excess mucus
- Bubbles around the mouth or nostrils
- Persistent open-mouth breathing
- Abnormal head positioning
- Repeated yawning
- Reduced activity
- Refusal to feed
Respiratory disease can be associated with inappropriate temperatures, stagnant air, excessive moisture, stress or infectious organisms.
Increasing humidity without identifying the underlying problem is not an appropriate substitute for veterinary assessment.
Mouth Health
Green Tree Pythons can injure their mouths by striking enclosure doors, mesh, tools or other hard surfaces.
Monitor for:
- Swelling
- Redness
- Discharge
- Broken teeth
- Inability to close the mouth normally
- Abnormal positioning of the jaw
- Refusal to feed
Persistent mouth abnormalities require veterinary attention.
Sexing
Sex cannot be reliably determined from colour, pattern or general appearance alone.
Experienced keepers or reptile veterinarians may use appropriate sexing techniques.
Incorrect probing can seriously injure a snake and should not be attempted without appropriate training.
Breeding
Green Tree Pythons are oviparous and lay eggs.
Breeding should only involve:
- Healthy adults
- Animals of appropriate age and size
- Correctly sexed individuals
- Animals in suitable body condition
- Animals with known health histories
Females should be in strong physical condition before breeding but should not be obese.
Seasonal changes in temperature, photoperiod and humidity may influence reproductive behaviour.
Any seasonal cooling should be gradual, carefully monitored and only attempted with healthy established adults.
Courtship and Reproduction
Courtship and mating may occur over an extended period.
Females may show changes in:
- Body shape
- Colouration
- Behaviour
- Perch selection
- Basking behaviour
- Appetite
A post-ovulation shed commonly occurs before egg-laying.
A secure laying location should be available before eggs are expected.
Reproductive females require access to a stable thermal gradient throughout the process.
Eggs and Incubation
Green Tree Pythons may produce approximately:
6–25 eggs
although clutch size varies according to the female’s size, age, locality and condition.
Eggs may be artificially incubated or, under carefully controlled specialist conditions, maternally incubated.
Artificial incubation is commonly undertaken at approximately:
29.5–30.5°C
Incubation commonly lasts approximately:
45–60 days
depending on temperature and individual development.
Eggs should not be rotated after development has begun.
Incubation equipment should be stabilised and tested before eggs are expected.
Egg incubation should only be attempted by keepers who understand temperature control, moisture management and the risks of condensation or excessive saturation.
Neonates
Neonates are usually yellow or red and gradually change colour as they mature.
Provide:
- Secure accommodation
- Appropriately sized perches
- A stable thermal gradient
- Suitable humidity
- Effective ventilation
- Fresh water
- Dense visual cover
- Careful monitoring
Many neonates begin feeding after their first shed.
Offer appropriately sized whole prey when the animal is ready.
Do not power-feed neonates to accelerate growth.
Steady development and appropriate body condition are preferable.
Lifespan and Long-Term Commitment
Green Tree Pythons commonly live for:
15–20 years or longer
Before acquisition, consider:
- Permanent enclosure requirements
- Heating and lighting costs
- Access to suitable prey
- Veterinary access
- Holiday and emergency care
- The animal’s specialised environmental requirements
- The possibility that routine handling may remain inappropriate
Final Husbandry Principles
Successful Green Tree Python husbandry depends on:
- Secure and appropriately sized arboreal accommodation
- Sufficient horizontal and vertical space
- Multiple properly positioned perches
- Dense visual cover
- Environmental complexity
- A genuine thermal gradient
- Avoidance of excessive heat
- Appropriate humidity cycles
- Effective ventilation
- Dry resting surfaces
- Constant access to fresh water
- Moderate whole-prey feeding
- Prevention of obesity
- Careful quarantine and biosecurity
- Minimal unnecessary handling
- Regular observation of behaviour and perch use
Green Tree Pythons can be exceptionally rewarding captives, but their specialised enclosure, environmental and management requirements should be fully understood before acquisition.
IMPORTANT INFORMATION:
This care sheet provides general husbandry guidance and does not replace species-specific research or veterinary advice. Individual requirements may vary.
If you have concerns about an animal’s health or care, consult a suitably experienced exotic or invertebrate veterinarian.
Information correct at the date of publication.
reptilecommunity.com | Revised: August 2026