I've told this story before on here, so I'll make it quick.
This was back in 2001, my 2nd year hunting north east of Winter, WI about 15 miles. I shot a deer about 4:00pm, just before dusk, swore I hit it, but couldn't find the blood in the leaves with a flashlight. Yes, I waited until it was dark as we had a party of 4 hanging out thinking there might be another.
Next day on my afternoon walk out to the stand, I found the blood trail, followed it about 300 yards, where I found the deer, dead, and the hind quarters GONE in less than 24 hours. Wolf tracks all around the area that year. This was only about 1000 feet from my cabin at the time.
They are out there, and they wait for what they want.