What is the term used when a JRT barks and bays at the quarry while underground?

The term used when a Jack Russell Terrier barks and bays at the quarry while underground is commonly referred to as "marking the quarry." This behavior demonstrates the dog's role in tracking and indicating to the handler and other dogs the presence of the quarry. When a JRT is marking, it is essentially communicating through vocalizations that it has located the quarry, which is crucial during hunting and working scenarios.

Marking occurs as the dog engages with the quarry, providing auditory signals that help hunters determine the dog's location and activity level. This behavior is important in the context of a working terrier, as it showcases the breed's instinctual skills and reinforces the bond between the dog and handler during hunts or searches underground. The focus is on the dog's expressiveness and ability to indicate quarry presence, which is a key aspect of the JRT's traditional role in hunting and working environments.