Black Australorps are heavy, dual-purpose chickens which originated in Australia. They descended from the black Orpington and crossed with the Australian Langshan.
Roosters and hens can be distinguished by their body carriage (their "stance") and shape/size of their feathers and comb. Roosters have more erect carriage, holding their heads higher than the highest point of their tails. Hens have deeper abdomens and more pliable pelvic bones to accommodate egg-laying. This characteristic of body carriage is the first noticeable trait seen in Australorps that can be used to distinguish males from females.