Quiet bows are super important. I shot one this year on the third attempt. First arrow hit a tree, second arrow was flat out ducked at 15 yards, he came back to see where the commotion was coming from and ate the third one....but he still ducked and it took him through the neck and down the length of the body. Went 60 yards with an arrow exit beside its tail.
Pound for pound, absolutely the toughest animal I have pursued, and that includes hogs. I've seen too many walk away in the short time I've hunted them.