ive had terriers nearly 40 years just for on top bushing for lurchers/ always used them as marking dogs/ i have owned and seen ones catch plenty of rabbits in cover over the years. Cant recall any putting a rabbit up on open ground and catching one.Caught plenty pheasant odd ducks a few hares nabbed in their seats. Squirrels and rats and the odd stoat Had some good days with terriers on moorland with rabbits clapped under the heather.