I just had this quest so I can tell you this.
There are plenty of traps and feathers in that spot, so if you pass by, it will be hard to miss them.
To find them, I walked zoomed in to the border of Coniferous tiles with a heathland in the South. The feathers were ON the coniferous tiles, bordered with Heathland.
Not sure tho if you can see an entire tile by climbing a tree, I need this confirmed, because I was under the impression that there is some area left out of your visual field after trying this. And no, I am not talking about areas with a different altitude. So just to be sure I checked a lot.
I suggest you to build/plant/see a loop snare, to understand what you are looking for. I think you will find about 5 loop snares and 20 feathers, so nevertheless it will be very hard to miss them IF you pass by them.
If I understand it right, the quest items are only generated once, when you get the quest.
Also get weapons with you, I stumbled over a wolf during this quest, luckily just one. Be prepared for little surprises. I also stumbled on a rabbit and a fox, but I let them go since I didn't want to ruin my search pattern. The wolf I had to fight tho.
Bottom line, I did it much quicker than the Robbers' quest, which was horrendous.