The Megapodiidae, commonly mound-builders or incubator birds, are stocky, medium-large chicken-like birds with small heads, and large feet. They avoid flying unless pressed and spend most of their time on the ground. All bar the Malleefowl occupy jungle habitats, and most are brown or black coloured.
They do not incubate their eggs with their body heat in the orthodox way, but bury them. They are best known for building massive nest-mounds of decaying vegetation, which the male attends, adding or removing litter to regulate the internal heat while the eggs hatch. However, some bury their eggs in other ways: there are burrow-nesters which use geothermal heat, and others which simply rely on the heat of the sun warming sand. Some species vary their incubation strategy depending the local environment or the season.
Many are shy, solitary, and inconspicuous, others live in colonies of many thousands of birds.
Chicks do not have an egg tooth: they use their powerful claws to break out of the egg, and then and tunnel their way up to the surface of the mound, lying on their backs and scratching at the sand and vegetable matter. They hatch fully feathered, active, and ready to lead an independent existence: there is no parental care apart from the nest itself; chicks simply wander away and fend for themselves.
There are 19 species in 6 genera, located in the broader Australasian region, including islands in the western Pacific, Australia, New Guinea, and the islands of Indonesia east of the Wallace Line, but also the Andaman and Nicobar Islands in the Bay of Bengal.
Although the evolutionary relationships between the Megapodiidae are especially uncertain, the morphological groups are clear: