One very talkative African grey parrot is said to have known more than 800 words. Only larger birds, such as waterfowl, have been completely domesticated, though. Most smaller birds, such as canaries and budgerigars, must normally be kept in a cage. Budgerigars are Australian parakeets. In the wild, they nest in a hole they dig in mallee scrub and line it with rotten wood.
Canaries are descendants of the wild serin finch or canary of the Canary Islands.
Their brightly-coloured plumage comes from selective breeding. Dogs Terriers were bred as sporting dogs. This is a cairn terrier. Domestic dogs are all descended from wild wolves and jackals, but only the German shepherd looks anything like its ancestors. There are now 130 or more breeds, from giant Afghan hounds to tiny chihuahuas.