We had a couple of 'possums and a couple of squirrels that we rescued and bottle raised. One of the squirrels took off into the wild; the other squirrel and the 'possums died of old age. The 'possums were great pets but the squirrels were bloody pests.

Animals that the cats or dogs brought in almost always died.

We also hatched a couple of snapping turtles and raised them until they were old enough to be accepted by a sanctuary.

Some animals (turtles and snakes) that were rescued from short term dangers such as busy highways. Well we just borrowed them for a couple of days, fed them and released them somewhere safer.

All in all I don't think you can make much difference in the grand scheme of things. But the kids grew up learning to love animals and respect wildlife.