It is most similar in plumage to the South Island tomtit, the nominate subspecies. A Mongoose engine powers the sole remaining airworthy Hawker Tomtit, based at Old Warden. In 1924 it was flying with a 696 cc Blackburne Tomtit engine. The term "tomtit" was originally a shortened form of "tom titmouse". Blackburne Tomtit two-cylinder engine. They also lay in robin ("Petroica australis longpipes) and" tomtit "(Petroica macrocephala toitoi)" nests. The Blackburne Tomtit engine was developed from Blackburne's motorcycle engines. Among his early designs were the Tomtit, Hornbill, Nimrod, Hart and Fury. Less common are the tomtit, Australasian harrier, wood pigeon and occasionally kea. The Chatham tomtit has been extinct on Chatham Island since the 1970s. It could be powered by either a four-cylinder Vaslin engine or a inverted-V twin-Blackburne Tomtit. The Hawker Tomtit is a British training biplane from the late 1920s. One Tomtit still flies, the ex-RAF "K1786" "G-AFTA".