on 2* land mass set up a breeding spot.
take /push the new 2* boars onto a boat (use a ramp n fence if u need ..or harpoon
since you have a breeding set on 2* landmass if u lose a boar that aggros a serpent.. u can try again
sail to new land mass by shortest path with moder power in case weather fouls you up.
repeat untill you suceed