Each animal have it's own quality parameter based on coords he spawned.
Make it so that spawn rate of animal spawn will depend on quality spot.
Of course it must be balanced - it is not a x3 or x5 more animals.
With that thing we will get something like natural environment, for example forest where will be a lot of bears or mooses.
Or a place in the lake where will be a lot of beavers, otters.
Hunting will be more interesting when you will focus on what you hunting, instead of random facing random animals.
And of course - it can be implemented not depending on spot, but i'm trying to make idea simpler to realize.