But I do not see what you do. Only I will take the time to explain what I see. And I will not deny or discard what your observations are. I will give another viewpoint.
In the picture with that floating thing. That appears to be a pair, the female on it, the male in the water next to it. If I found that, I would consider that a good candidates for study. They have possibilities. I would not make to much about what they are doing on that floaty.
The other pic of one chasing another up a tree, yes, that is very commonplace and practiced amoung social critters. If you will notice, its a young animal. It most likely is a transient and is being put in its place. Also consider, if the chaser wanted, it could very easily keep chasing that animal and kill it. Why didn't it? sir that is a good question. But I am guessing it did not. I am guessing it chased it up a tree and left it there. That is simple labelling. The little one is being reminded of its place. do I dare say colony/group.
Also it surely does not mean the little one is not part of the group or colony. I believe you will read about this stuff in many of Jane Goodalls books and see it in her films. (i helped do some work for her)
The real concern is, not what they are doing when you saw them. But what they did before and after you saw them. If you notice in the pics of the gilas, they had just emerged from their hole. The whole group lived in one hole. Then after they warm up, they will move in seperate ways and accomplish their needs, then return to this hole. Sometimes they spend the night in smaller less secure temporary holes, then return a day later or two. Back to the group. Instead of fighting forth and back. There are so many good questions to ask.
I feel the error is that you assume what they did after they left, you do not know what they did. Sir, those are two different things. I was under the impression that to assume in science is wrong. But what do I know.
I suggest you find out where they emerge from and go back to. If you do not break their defenses(harass them) they will often return to the exact same hole or hollow, or use a small series of holes and hollows. Sir, that is the start to learning what they do, its not the end. Once you find their homes. You can start to see what their lives are like.
I do understand, its very easy to find a monitor or a lone gila, I do not make to much of it, until I know what it did before and after I saw it. Finding lone animals surely does not define any animal, social or otherwise.
You see, what I gripe about is, people making so much from a monitor on a floaty or limb. I hope you do find where they go.
I also understand, seeing that with larger monitors is not an easy task.
To help you a little, I have studied many reptiles in nature, in most cases, they follow a basic model. Actually there are several models. Each model has parts. Once you know these parts, then it makes the hard species much easier to study. I think monitors are amoung the hardest, because of their name. MONITOR, they do know whats going on around them.
I do thank you for the pics, as it gives me and you, something common to talk about. Also understand, now that you have gone this far. I would not respect you if you, "believe" anything I say. I would respect you if you heard what I said, then investigated it. To try and find it, in nature. Or to test it in captivity. Not to believe it.
All I ask, is to look for something you obviously have not looked for.
About being social. Let me explain(something you never asked for) First, all standard methods of study, are not designed or monitors(or any reptile for that matter). All models for behavior are not based on monitors(reptiles). All terms and defintions are not based on monitors(reptiles). Lastly, all formulas and math, were not developed for monitors or any reptile. So how on earth could monitors fit any term, defintion or model? They cannot and they won't. So yes, I do understand, they do not fit the extreme mammal(hoofed stock) defintion of social. But neither do most other types of animals that are not hoofed stock. Heck, humans don't fit that model either.
But because they don't fit a model thats not designed for them. Does not eliminate varanid behaviors that are social like, by definition and more importantly, by action.
Let me say this, it surprises me to no end, that all you fellas can do is argue about whether monitors are social or not. I would have expected a much more sound and logical line of questioning. For instance, How did FR find all those monitors, all those weird ones, that do not appear to be discribed. All those variations and different color morphs. How did he do that? Specially because he(fr) understands so little about monitors(by your defintion)
How could I find all of that, no one else has those pics. Sir, the fact that I did and did so in such a short time, hints of a different set of varanid understanding. Yes, I would be far more concerned at that. Cheers and thanks for the pics.