All domesticated ducks are believed to be a descendent of the Mallard Duck. The Mallard is a native species to most countries in the Northern Hemisphere.
Originally bred for meat and eggs, such as the Khaki Campbell and the Aylesbury duck, these birds grow fast and egg production is prolific.
Most breeds these days are kept by hobbyist, each of who will generally keep a specific breed. As such, there are over 30 different breeds of domestic duck. Each breed has its own distinctive look and character, for instance, the upright stature of the Indian Runner Duck, or the ‘pom-pom-like crest’ on the back of an Aylesbury Duck’s head – the result of a genetic mutation.
However, many of these so-called ‘fancy’ breeds are now generally kept as pets and for showing rather than for eating.