So far, I have only discovered 4 hunt marks:
The 10-, 20- and 50-point ones in the part-2 area and the 50-point one in the part-1 area.
For the p2 area I only discovered them because I was doing the first quests there and I defeated the 20- and 10-point ones a few times without knowing about the hunt board. (Leaving the BHE area the 20-point hunt is to the left and the 50- and 10-point hunts are to the right.)
For the p1 area I only discovered the 50-point one because it happened to be there while I was passing through to do the minor heroic at the end. (located in the area where you burn the crates and free the prisoners.)
For the p2 area I got the impression that there may be a pattern and that you probably need to watch the animals as well to determine when they should be there as I am pretty sure I only saw them when the deer# was there and when I did it, all the hunt marks showed up at the same time.
# There is a non-hostile creature that you notice when entering the clearing where the 20-point mark is. Currently, for the p2 area, I presume that the non-hostile changing creatures are sort of location markers for where to find the hunt marks. It may be the same for the p1 area but I never actually looked for any hunts while I was there so no idea.
From what I could tell I never saw the hunt mark when there was a chicken, boar or cat-like creature there. I may have missed a few as I was not initially paying attention to it until I noticed the change at some point.
Because I found the 50-point ones first I never really bothered to look for the others and I essentially was able to complete my quests in a short amount of time.
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