Owls are zygodactyl, which means their feet have two forward-facing toes and two backwards-facing toes.
How cute are those lil feet???
Fancy Foot Facts:
The one toe has a wide range of motion, so it can move up to the front for a 3-1 grip if it wants.
Tendons in the legs lock the toes tightly closed by default, and the grip is only released by lifting up with the legs. This is how owls keep from falling out of the trees while they sleep. The more snuggled down they get, the tighter they're clamped on.