The Jack Russell Terrier is named for the Reverend John Russell, a nineteenth-century hunting parson in Devon, England, who wanted white terriers that could keep up with hounds and bolt foxes from their dens. Today's dogs are compact and mostly white, about 10 to 15 inches tall, with black or tan markings and smooth, broken or rough coats. The taller show type is registered in the US as the Parson Russell Terrier.
In Tyler, that working background shows up as a gap under the fence or a squirrel in the pecan tree. Many Jacks are bold, clever and funny, with strong prey drive, and they're rarely content as couch dogs. Daily exercise, training games and firm, kind boundaries matter a great deal, and dogs vary, so an adult's actual habits are worth learning.