Green tree python: why its diet shifts along with its colour
Published by Planète Pets · managing editor: Clément Lacaille · how our guides are written
In young green tree pythons, the bright yellow or red colour at hatching is more than a cosmetic detail: it tracks a real change in diet as the snake grows and turns green. A study by Natusch and Lyons, published in 2012 in the journal Biological Journal of the Linnean Society, compared head shape and diet in green tree pythons (Morelia viridis) from three different populations, at several stages of growth and colour change. Find our other pointers in the food section.
Contents · 5 sections
A diet that shifts from cold-blooded to warm-blooded prey
In two of the three populations studied, the shift from bright yellow or red to adult green came with a clear change in diet: young, still-coloured pythons mostly caught ectothermic prey (frogs, small lizards), while green adults turned mainly to endothermic prey (birds, small mammals).
A head that widens along with the diet
This dietary shift came with a change in head shape, wider in individuals catching endothermic prey, which are bulkier and harder to swallow than a lizard or a frog. The authors link this triple change, colour, head shape and diet, to the same maturation process, without claiming that one factor directly causes the other two.
What this means for feeding in captivity
In a terrarium, a still-yellow or still-red juvenile green tree python generally does better with small, easy-to-swallow prey, before moving without trouble to larger mouse-then-rat-sized prey as it turns green and grows. A one-off refusal of prey that's too large for a young snake doesn't necessarily signal a health problem; it may simply reflect a developmental stage where its body isn't built for that prey type yet.
Practical pointers
- Prey sized to the colour stage: small, easy-to-swallow prey while the python is still yellow or red.
- Increase prey size gradually as the green colour sets in.
- Don't over-worry about an isolated refusal of prey too large for its age.
- A properly set-up vertical terrarium makes elevated hunting perches easier to use once the python is a confirmed arboreal adult.
This diet question ties into housing, which matters for such an arboreal species; our article on choosing a vertical or horizontal terrarium by species covers what a climbing snake needs. See also our article on the ball python's digestive remodeling for another example of a feeding-linked adaptation in pythons.
Frequently asked questions
Should prey size jump abruptly once the green tree python turns green?
No, the colour transition unfolds over several months; increasing prey size gradually, tracking the animal's growth, is safer than a sudden change.
Does this dietary shift show up in every green tree python?
The study found it clearly in two of the three populations; the third showed a weaker trend, suggesting it may vary by geographic origin.
Can an adult green tree python still eat ectothermic prey?
Yes, the study describes a dominant dietary trend, not a strict exclusivity; an adult remains able to catch a smaller ectothermic prey item occasionally.
An accessory from our shop for this use: Stick-on digital thermometer for aquarium and terrarium glass (€18.90) · the whole shop
This guide is part of Planète Pets’s Reptiles universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.