Kristina, I liked what you had to say. More on that is a curious thing.... in that I have different calls for different expectations that I have of my chameleon. I have a call that I do that brings him to the top where I can see him. It works.
It's good that you are paying attention to these cues and sharing them. Do you keep a journal? You can start testing your ideas by using a blind and playing recordings of your vocal cues, and observing his reactions (remotely via camera would be even better). I've talked to a few keepers who say their chams climb to a certain part of their enclosure on cue. It's a good minimal-stress management technique when you need to fix or clean a part of the cage.
I also have a new curious thing going on. I sing to him a certain way and he comes over to my face and enlists my fingers to stroke his face.
It's probably the rhythm of the tones that he is responding to, along with the rhythm of how you breathe as you sing, and how the singing calms
you. The unconscious parts of your communication are most likely what he's reading. I have noticed, but lack video evidence, that when wrens sing outside their cham-room window, the chams take interest, even as the wrens are out of sight. They also become positively excited at the song of cicadas in close proximity. Rhythmic or trilling sounds are immediately noticed and significant to chams. This includes some music, try it for yourself.
When you say, "enlists", do you mean, he walks under your hand and shoves his face into your fingers? Does he rub his skull crests (orbital, parietal, temporal) and eyes back and forth on your fingers? Or does he sit still and "look" as if he wants to be rubbed, then accepts it when you pet him? If it is the last one, that is not the cham, it's most likely your interpretation.
Lately he's been wanting to love bite me. Soft bites. It's becoming a daily ritual with us that we have this singing/touching thing now. What are the possibilities of what is really happening?
What is really happening is open to a number of interpretations, depending on the school of behavior theory one ascribes to, I suppose. I don't hold a degree in ethology or general behavior, so take with a grain of salt...
Just my opinion based on my observations, but I haven't seen anything I'd label "love bites" in chameleon behavior. I'm not sure I like the term, even in mammals, because it's not
love that they are communicating. They are trying to assert dominance, learn about a novel texture, practice killing prey, etc. Mouths are their organs of touch, just as we have hands. Rather than "love bite" to indicate and enhance a bonding emotion, some mammals will
groom. Since chams don't groom with their mouths, and opportunistic eating of another cham's shedding skin is not grooming with intent to bond, that option is out. From what I have seen, the context of cham bites, no matter how gentle, is one of these:
1. tentatively trying/testing a prey item or leafy or woody browse
2. exercising kill bite on branches
3. asserting or testing rank (only in groups, such as young chams being raised together*)
4. unreceptive response to courting male
5. some species' males will bite the females during mating
6. competition for mate and/or territory
It's important to remember that chameleons are creatures of minimal wasted energy. They don't do anything unless they absolutely need to, which means the little gentle bites are not accidental. I suspect it's either curious about your texture and potential as a food item, or it is trying to convince you, gently, that it is the dominant vertebrate. In either case, a cham doesn't have to bite
hard . If your cham is just trying to "get intimate" with you, you will know sooner than later.
I had a giant who would rub his skull crests on my fingers, whenever they were in his range. He would climb over, and scrub the crests like any animal does to scratch an itch against a tree or rock, putting all his body weight into it. He'd rub until his lip on the lower side relaxed and hung open. He never used his teeth. From his web page:
"Ferris had a habit of running his head up under my hand and rubbing, like a cat will. He'd relax his lips, close his eyes, rub the orbital crests and rostral ridge, then his eyes. I have never met another chameleon that would actively seek a petting."
I think when chams are tame and acclimated to people, they might equate us with heat-radiating, mobile trees. They may scratch themselves, taste test, and perch on us as if we are just that. They feel safest with their own mobile tree, while others are so tame they think no "mobile tree" will harm them.
*Group housing is NOT for everyone, and not to be done lightly. Most cham species do best in the limitations of captivity when they are kept singly.