I agree with Nunamiut. Sometimes they kill because they are hungry and
sometimes just for the fun of it. I have seen them kill a lot of moose and
just eat the tongue or maybe not eat any of it, then leave it and never come back. I also found where a pack of 14 traveled a little over 40 miles, killed an adult moose and totally consumed it, bones and all, in about 18 hours time. They were obviously pretty hungry. The only bones left were the parts of the jaw bones with the teeth in them, the hip joint sockets from the pelvic bone
and the hooves (and the toe bones were chewed out of them). The hide was chewed and puckered and most of the hair chewed off it. It takes some powerful jaws to crush up all the vertebra, pelvis and skull bone on a moose like that. That's the only kill I have found that was that well comsumed. Most of the time they do not eat the major bones.
On the questions brought up by Martenpine the moose in the first picture did not have antlers nor antler bases on the skull. This time of year the bulls have all shed their antlers anyway, but you can still tell by looking at the skull if it was a bull or cow. As far as the age of the moose all I can say is that judging from the size of the hooves and the bone structure it was an adult moose, and I have a habit of referring to any female moose
as an "old cow".
Getting a good count on the number of wolves in a pack usually requires either a visual count or you have to follow their track for a ways. A lot of the time they follow single file especially in deeper snow and it is very hard to get a count on them. But on harder snow they will often fan out across the open places and you can get a good count on the tracks. This pack had came down river for a couple of miles and there were several places where it was easy to count tracks.
We don't have deer or caribou in this area but they do change up their diet occasionally;