Question: The African ostrich is the world's tallest living bird; where does the second tallest, the emu, come from?

Context articles: Emu
Flightless bird
Masai ostrich
South African ostrich
Bao Xishun
Alam Channa
List of tallest buildings in New Jersey
Common ostrich
List of largest birds
North African ostrich

The emu ("Dromaius novaehollandiae") is the second-largest living bird by height, after its ratite relative, the ostrich.
 It is endemic to Australia where it is the largest native bird and the only extant member of the genus "Dromaius".
 The emu's range covers most of mainland Australia, but the Tasmanian emu and King Island emu subspecies became extinct after the European settlement of Australia in 1788.
 The bird is sufficiently common for it to be rated as a least-concern species by the International Union for Conservation of Nature.
Flightless birds are birds that through evolution lost the ability to fly.
 There are over 60 extant species including the well known ratites (ostrich, emu, cassowary, rhea and kiwi) and penguins.
 The smallest flightless bird is the Inaccessible Island rail (length 12.5 cm, weight 34.7 g).
 The largest (both heaviest and tallest) flightless bird, which is also the largest living bird, is the ostrich (2.7 m, 156 kg).
 Ostriches are farmed for their decorative feathers, meat and their skins, which are used to make leather.
The Masai ostrich ("Struthio camelus massaicus"), also known as the pink-necked ostrich or East African ostrich, is a large subspecies of the common ostrich native to East Africa.
 Today it is farmed for eggs, meat and feathers.
The South African ostrich ("Struthio camelus australis"), also known as the black-necked ostrich, Cape ostrich or southern ostrich is a subspecies of the common ostrich endemic to Southern Africa.
 It is widely farmed for its meat, eggs and feathers.
Bao Xishun (also known as Xi Shun; born 1951) is a herdsman from Inner Mongolia, China, recognized by "Guinness World Records" as one of the world's tallest living men.
 On September 17, 2009, Turkey's Sultan Kösen overtook Bao Xishun as the tallest living man in the world, when he was measured by Guinness World Records, standing 2.51 m tall.
Haji Mohammad Alam Channa (1953 in Sehwan, Sindh province, Pakistan – 2 July 1998 in New York City) was one of the tallest living people.
 According to the Guinness Book of World Records, the tallest living man in the world (between 1982 and 1998), was Pakistan’s Mohammad Alam Channa.
 Before his death in 1998, Channa was reported to be 7ft 8 inches tall.
This list of tallest buildings in New Jersey ranks skyscrapers and high-rises in the U.S. state of New Jersey by height.
 The tallest building in New Jersey is the 42-story 30 Hudson Street, known widely as the Goldman Sachs Tower, which rises 781 feet (238 m) at Exchange Place in Jersey City.
 It is also the 69th-tallest building in the United States.
 The second tallest building in New Jersey is the 57-story Revel Resort, which rises 709 ft (216 m) in Atlantic City and ranks as the second tallest casino tower in the United States.
 The National Newark Building was the tallest building in the state between 1931 and 1989.
 If built, a proposed 950 ft residential building in Downtown Jersey City would become the state's tallest.
The ostrich or common ostrich ("Struthio camelus") is either one or two species of large flightless birds native to Africa, the only living member(s) of the genus "Struthio", which is in the ratite family.
 In 2014, the Somali ostrich ("Struthio molybdophanes") was recognized as a distinct species.
The largest living bird, a member of the Struthioniformes, is the ostrich ("Struthio camelus"), from the plains of Africa and Arabia.
 A large male ostrich can reach a height of 2.8 m and weigh over 156 kg .
 A mass of 200 kg has been cited for the ostrich but no wild ostriches of this massive weight have been verified.
 Eggs laid by the ostrich can weigh 1.4 kg and are the largest eggs in the world today.
The North African ostrich or red-necked ostrich ("Struthio camelus camelus"), also known as the Barbary ostrich, is the nominate subspecies of the common ostrich from West and North Africa.
 It is the largest subspecies, making it the largest living bird.