It's hard to tell the actual size from those prints. Snow always makes prints look larger because of the way snow recedes or puffs out during the entry and exit. Especially in snow deeper than 1-2 inches. The same animal will look different on snow versus dirt/mud. In this case, at best you'd have to measure down in the bottom with a pad to pad measurement and allow for some natural melt back. Any idea how old the prints are? If they're fresh...under a couple hours max, the fact it compressed the snow down to the fallen leaves indicates a heavy animal. If they from the previous day, the temperature would have played a part in that, and the size. It certainly looks like a large animal though.