My wolf experience has been similar to Vern's....
Last year we were in an area where we saw several moose the first couple of days, and we heard a couple more that didn't come out. Took one on day three, and as we were leaving the kill site and humping the last load back to camp at last light we heard several wolves back in the timber calling back and forth to each other. Heard them several times howling during the night for a couple more nights, working the kill site. Didn't see another moose for about five days.
I've also shot wolves when moose hunting. About ten years ago we had a male and female stalking in at last light after I had been calling all evening...I'm pretty sure they were responding to the calling. My hunting partner and I each shot one. A few years after that we had gotten a bull on the first day that was hanging. I was on a hill glassing in the morning a couple days later, and around 10 or so a legal bull slowly walked to the base of the hill and laid down about 80 yards below me. We were not interested in taking a second moose that year. That bull was dragging and he was dead tired, and put his head down right away. About fifteen minutes after he laid down a wolf appeared and walked right up to him. The bull raised his head and just looked at him...my impression was that they had already been introduced, and that wolf had been pushing that bull to wear him out for a very long stretch. I shot the wolf.