Colour Change in Tree Snakes

[Snakeluvver2]

So, as some Tree Snakes grow they change their colour from Green to Blue.
This can take several years whether it be in the last few years of it's natural life or within the 1st 7 years or so.

Why do they change colour?
Is their scales losing colour and the skin underneath showing through? Is it to do with diet or genes? I truly don't think it's locality based (unless your not talking about specifically green coloured tree snakes)
Is there any colour change in other phases such as Black Tree Snakes and Golden Tree Snakes.

 

[Jdsixtyone]

Bump - sick of the other threads that are boring!

 

[saximus]

I have nothing intelligent to add but would it be for the same reason that GTPs go blue after breeding? I would assume more research has gone into them so something could be learned from that if nobody has researched why it happens to GTSs

 

[eipper]

blacks start out as chocolate brown and get darker each shed

Blues are blue from the start but usually with a slight grey tinge

 

[Waterrat]

Many, many species of snakes change colour as they grow / mature / get old. Some change colour from light / dark seasonally, some as a result of hormonal activities. I don't thing the changes in common tree snakes is exceptional in any way and is certainly nothing like OCC in GTPs, so it doesn't make a good comparison.

 

[sandswimmer]

For green tree pythons, research conducted by Wilson et al. 2007 has shown that the ontogenetic colour change in GTPs provides camouflage from visually oriented avian predators in the different habitats occupied by juveniles and adults . In other words, hatchies remain on the ground at the rainforest edge where red/yellow colouration provides better camouflage from birds, while adults live in the canopy in the rainforest interior, where green provides better camouflage. It might be similar for green tree snakes - do adults and juveniles inhabit different areas? Or it could be something completely unrelated.

If you're interested, you can have a look at the article published by Wilson et al. on ontogenetic colour change here:
The adaptive significance of ontogenetic colour change in a tropical python