Largest bird-constructed incubator

The malleefowl (Leipoa ocellata) constructs massive nests containing up to 229 m³ (8,100 ft ³) of matter, and weighing 300 tons (661,386 lb).

The nest-mounds of malleefowl are unique in the bird world. Males work on the nest in most months of the year, digging out a hole, then scraping leaf litter into it and covering it with sandy soil. Alternatively an existing mound may be used and mounds which are used year-after-year can reach a diameter of 5 m (16 ft). The female lays eggs in chambers excavated by the male.Rotting vegetation provides heat need for incubation. Once laid and covered, the eggs themselves are ignored by both parents, as are the chicks, which hatch in 50–90 days.