We've had a few questions where answers state, to a lesser or greater degree, "humans would investigate this ability to figure out how it works" in another creature with abilities not readily scientifically explainable and in-universe explained by magic - for example here and here.
For the purposes of this question, on one side we basically have humans as we know them, on a planet very much similar to Earth (not necessarily humans on Earth, but it could be) and at a technology level similar (but not necessarily identical in every respect) to our own present-day level; and on the other we have creatures that:
- are sapient, intelligent, biological creatures
- are predatory, though not necessarily (and most often not) of humans
- are essentially wilderness-dwelling with minimal to no interaction with humans, and while the odd exceptional individual exists, for their part are generally happy to remain that way
- rarely (but sometimes) encounter humans, mostly humans who voluntarily venture into said wilderness
- have little (think perhaps medieval level at most) to no technology, and generally see no need for technology, though they have command of fire; some trade with humans their services for some items of non-electrical technology, while some shun all forms of contact with humans and human technology
- tend to live in extended family groups, normally made up of anywhere between just a mating pair and a few mating pairs plus their offspring of varying age
- are voluntary shapeshifters, with one animal-like1 and one human-like form, though the human-like form is distinctive enough that they cannot pass as "humans" except possibly in a tiny number of cases. How they evolved this capability is beside the point of this question (for the purposes of this question, just assume they've always been around and always had this capability).
The creatures in question are intelligent and communicable enough to be able to choose representatives to speak for them as a species, perhaps in the United Nations general assembly or a similar forum, and negotiate with humans. They are also good enough hunters and fighters that for one of most of them to kill one of most of (unarmed) humans is trivial to easy, and few other species of animal pose much of a problem to one or more determined hunter(s) among them. Both of these capabilities are for the most part independent of the current form of the individual; when shapeshifting, they remain the same individual (personality, memories, experiences, physical size, most physical abilities, etc.) but take on a different physical form. These abilities make them great hunting or guarding companions for humans, when they are willing to offer their services to humans. Humans recognize these abilities in them, though few have actually encountered one of these creatures in either form; think perhaps like penguins in the wild and humans.
I want these creatures to (more or less) peacefully coexist with humans, the humans generally accepting that the creatures want to be left to live their own lives, without the humans trying to analyze them apart or restricting them to fenced-in zoos. (The creatures could, however, use their ability to negotiate to enter some sort of worldwide truce including some land, something like one or a few country/countries of their own.)
Without straining suspension of disbelief too much, how can I explain that humans would be leaving such creatures more or less alone, rather than trying to capture them and try to figure out how the shapeshifting works, or trying to simply use them for their own gain?
1. I know that technically humans are animals, even though most humans do not consider themselves to be animals.
