The Border Collie Jack Russell Terrier for example. It is a medium sized dog with moderate amount of coat.  They can be of any colors like: black tricolor, red and white, red tricolor, blue, lilac, red merle, blue merle, and brindle. Australian red/ gold is also seen frequently. Their eye color varies from deep brown to amber or blue. Their ears are fully erect; while some has fully dropped ears and others has semi- erect ears. This hybrid is being purposely developed for the agility sports and flyball. They are a calm breed and sweet with their owners. These dogs tend to be very intense and busy, requiring a lot of activity. Experienced handlers and pet owners are advised for this breed and the need a lot of daily exercise