Based on luck, use one bird to gurantee three stars but you can 3 stars with two birds.
For Fry Me To the Moon 3-4, fire the Black bird into the first wooden structure. The key to the explosion is to pop both the TNT and smaller pig in the space suits above. Doing so should cause enough chaos to clear all pigs. Alternatively, a slick strategy is to fire a Black bird just below the pile of stones in the bottom-left.