@Lafone Thank you. I was hoping for a better shot, but the birds are actually quite shy and keep hiding in the bushes. I wanted to spend more time with them, but staying in the sun when it's 35°C was basically impossible. When one of the birds finally left their hiding spot, I accidentally "cut" the end of their tail off the photo I hope I'll do better next time!
@merlin Really illustrates the similarity between wild bird and captive birds, the latter have the certainly they are at least there somewhere but it's still a challenge to grab them!
This picture is an excellent example of the problems with keeping this species in aviaries with enough cover from the sun. The yellow pigments in the feathers is highly sensitive to UV-exposure and does fade away. In the wild this species lives under very dense canopy and the shade keeps the green colour vibrant.
@Conservationbiologist Yes, I know, it's quite unfortunate... I've also read it is not the only cause and that it also has something to do with feeding?
@merlin Interesting I saw the ones at Chester having some pieces of what looked like mice - guess they have a varied diet like most Corvids. They do seem quite green so would be interesting to know the split of environment and diet.