How a Jack Russell Terrier Uses Vocalism to Hunt Its Prey
A reason that vocalism makes the Jack valuable is that they will often follow prey into their burrows and tunnel after them underground. If the dog is already underground the only way to know the location of the dog is to follow the sound of its bark coming from beneath the soil. Jacks sometimes find themselves stuck in these tunnels, which is why every good hunter brings a shovel with him in order to dig the Jack out if the need arises.
The bark can often let the hunter know where to dig in order to get close, and where not to dig, so the dog isn't injured by the shovel. This is why the Jack Russell was bred to be very vocal, and why even non-hunting Jack Russell's today exhibit this trait. The Jack Russell Terrier has also been bred to be very intelligent. The nature of the work that Jack Russell's are meant for is unpredictable at best.
There is rarely a consistent hunting experience unless a hunter chooses to hunt the same spot every time of a regular basis. This is rare. Even if the same location is used consistently, there are often obstacles that haven't been encountered on previous hunts. The most valuable Jack Russell's are the ones who can meet challenges and do complex problem solving on the spot in order to gain the advantage. Much of the prey hunted by the Jack Russell, such as the fox and the raccoon are equally as intelligent and it takes a clever dog in order outsmart the sly and elusive game it is hunting.