There are 6 kinds of animals you have to kill:
Crow - 1 hit
Snake - 1 Hit
Rabbit - 1 hit
Boar - 2 hits
Wolf - 3 hits
Bear - 4 hits
The first 3 are easy. The crow and snake usually don't move, and you can sneak up to the rabbit.
The other 3 will obviously charge at you. The best way to get around this is to use the safe zone at the end of the wooden walkway into the zone. Near the end of the walk, you'll notice that you can stand without being attacked. You can abuse this quite a lot to hunt and such.
Shoot one of the creatures or somehow get them to chase you (which shouldn't be hard), then hit them from the safe zone. You'll have plenty of time to line up your shot. You can go back to the landing if you need to without losing any shots you've landed.
Hope this helps!