I find it quite common for some of my chams to chew on some of the leaves from the live plants that are in their cages. I'd have to say mosty I catch them with ficus leaves hanging out of their mouth. However, grape vine bark probably isn't the best thing for them. Their is a good chance that if he gets a piece thats to big, it could cause a blockage. If I were you, I'd get that grape vine out of there and shave all of the bark that he could possibly chew on, off of the thing. Once all the bark is off I'm sure the grapevine would be a more than adequate perch for your cham. I hope this helps.
I have seen my panther chew on leaves before, but it is usually by mistake. Sometimes the cham will shoot at some silkworms on a leaf, and end up pulling the whole leaf into its mouth. Other times the chams tongue will stick to the leaf, and he will walk towards the leaf and take a bite out of it in order to free himself. I think 2by2 offered some good advice above.
Thanks Brad. Your right, alot of times it is by mistake that I see them eating a leaf. However, I've seen them just decide that they felt like a leaf for dinner. I think its definately more common in veileds, as I notice my veileds do it more often then my panthers. But I think sometimes even the panthers feel like they need some green in their diet. Either way, It doesn't hurt them so I just let them chow down.
I have never seen my cham do this, but I have heard it is normal especially in juveniles. It has been referenced many times on a variety of lists I belong to, and most keepers seem to think it is a natural occurance. Perhaps in the wild, a cham will get some trace elements from wood chewing.
This is interesting and good to know! I am getting a nosy be next month and one of his granddaddy's is from Screameleons - gotta respect their knowledge
I had not heard this and have only had veiled and brevi's. Luna would munch on leaves but she never chewed on bark. Let us know if you find anything else out - I wonder what the reason would be (bark, not leaves).