It's not a racoon or opossum, they both have hand-shaped prints (like a person's hand). If it has claw marks, its probably a red fox. If there's no claw marks, its gotta be a cat. If its not a house cat, it could be a bobcat. Both bobcat & fox prints are around 2" in diameter. A pika is also has a really round footprint, its only about 1" in diamter, it also has little clawmarks.
The more I look at your prints & the prints in my book, the more I think its a pika (a little critter about the size of a squirrel, but looks more like a chipmunk).
I was thinking bobcat , the tracks are all about the same size and from the illistrations on the chart they seem to fit your pics footprints , or a large housecat .
Those are not bobcats tracks, the tracks in snow are usually a slight bit bigger than the feet and a Bobcats foot is three times the size of that quarter, a domestic house cat is your best bet, but another possibility is a skunk, or if you're in Canada one of several members of the weasel family, Martins, black tailed ferrets etc, the mention of the Red fox is also a very very likely possibility because they are very uninhibited by people and would be comfortable near your house looking for mice and other critters that stick close to people in very cold weather. Any of these are bad for chickens or fowl, but I have learned that many more critters go near your fowl, but do not go after them than you would think, and generally during a good snow you find out who's around. If its not bothering your birds, i wouldn't worry at all.