In temperament it is alert, tireless and quick to learn, usually devoted to its own people and reserved with strangers. Many carry a small white forehead patch, the Bentley mark, which tradition traces to a single dog owned by a drover named Tom Bentley.
It is a compact, muscular dog with a broad head, pricked ears and a short, dense, weather-resistant double coat. The coat is either blue, mottled or speckled, often with tan markings, or an even red speckle. Puppies are born white and colour in as they grow, a trait popularly but uncertainly credited to Dalmatian ancestry.
The Australian Cattle Dog took shape in New South Wales, where the pastoralist Thomas Hall's crosses became known as Hall's Heelers in the mid-nineteenth century. After his death, breeders around Sydney, among them, by the usual account, the Bagust brothers, refined the type, and Robert Kaleski drew up the first written standard near the end of that century. A naturally bob-tailed relative, the Australian Stumpy Tail Cattle Dog, is now treated as a separate breed. It was bred to work cattle quietly, moving them by darting in to nip at the heels and then dropping low to avoid a kick.