Sight hounds, such as the Greyhound, are built for speed and hunt by sight. Historically they used to kill their prey. Sight hounds are among the earliest known dog breeds known to man and were named after the prey which they were historically bred to hunt for example the Deerhound hunted deer and the Wolfhound hunted wolves. Consequently, the now extinct Kangaroo Dog of Australia is included in this section as is Australia's 's wild dog, the Dingo. Although these two are not recognised as pure breeds, they deserve to be included among the Sight Hounds on this Australian website.