Rhvd is the main evil on rabbit populations. Add all the methods of control, especially summer hunting. Kill a doe , is she feeding young/ carrying young . And if a few survive and a new population is started, it's more susceptible to disease etc . They actually do need a hand , so instead of wiping everything out. Try replenishing small pockets near houses and public parks where no one can get at them as the snowflakes will protect them . Fingers crossed they branch out