The Border Collie is a working and herding dog breed developed in the Scottish borders for herding livestock, especially sheep. It was specifically bred for intelligence and obedience. It is very fetch-oriented. The median longevities of breeds of similar size are usually 12 to 13 years. Other enthusiasts oppose the use of border collies as show dogs, for fear that breeding for appearance will lead to a decline in the breed's working dog traits. Few handlers of working Border Collies participate in conformation shows, as working dogs are bred to a performance standard rather than appearance standard. Likewise, conformation-bred dogs are seldom seen on the sheepdog trial field, except in Kennel Club-sponsored events. Dogs registered with either working or confirmation based registries are seen in other performance events such as agility, obedience, tracking or flyball; however, these dogs do not necessarily conform to the breed standard of appearance as closely as the dogs shown in the breed rings as this is not a requirement in performance events, nor do they necessarily participate in herding activities.