what do they eat?
Berries, grass and seaweed.
King Island emu
They fed on berries, grass and seaweed. 
what is the king island emu? It is an extinct subspecies of emu. when did it go extinct? 1805 what was their relation with humans? The species were first recorded by Europeans in January 1802 where was this? King Island which sea or ocean surrounds this island? UNANSWERABLE what other species can you find on this island? UNANSWERABLE can you please describe the extinct species? It had darker plumage than the mainland emu, black and brown and had naked blue skin on the neck. so this species does still exist today in other parts of the world? Yes, several emu specimens belonging to the different subspecies were sent to France.
wiki:4441348
King Island emu [SEP] Introduction
The subspecies was distinct from the likewise diminutive Kangaroo Island emu ("D. n. baudinianus") in a number of osteological details, including size. The behaviour of the King Island emu probably did not differ much from that of the mainland emu. The birds gathered in flocks to forage and during breeding time. They fed on berries, grass and seaweed. They ran swiftly and could defend themselves by kicking. The nest was shallow and consisted of dead leaves and moss. Seven to nine eggs were laid, which were incubated by both parents. Europeans discovered the King Island emu in 1802 during early expeditions to the island, and most of what is known about the bird in life comes from an interview French naturalist François Péron conducted with a sealer there, as well as depictions by artist Charles Alexandre Lesueur.