Birds That Bury Their Eggs To Hatch Them

 Megapode, also called Mound Builder, or Incubator Bird, (family Megapodiidae), any of 12 species of Australasian chickenlike birds (order Galliformes) that bury their eggs to hatch them. Most species rely on fermenting plant matter to produce heat for incubation, but some use solar heat and others the heat produced by volcanic action.

                                                    

All are browsers, all but the Malleefowl occupy wooded habitats, and most are brown or black colored.

Megapodes are superprecocial, hatching from their eggs in the most mature condition of any birds. They hatch with open eyes, with bodily coordination and strength, with full wing feathers and downy body feathers, able to run, pursue prey, and, in some species, fly on the

Megapodes are of three kinds: 

• scrub fowl 
• brush turkeys (not true turkeys)
• mallee fowl
• lowan (Leipoa ocellata)

                                                

scrub fowl

                                            

brush turkeys

                                                        

•                                                               mallee fowl

                                            

•                                                           lowan (Leipoa ocellata)

which frequent the mallee, or scrub, vegetation of southern interior Australia. The mallee fowl, the best known of the group, is 65 cm (25.5 inches) long and has white-spotted, light brown plumage. The male builds a mound of decaying vegetation, which may require 11 months to construct. 

Megapodes do not incubate their eggs with their body heat as other birds do, but bury them. Their eggs are unique in having a large yolk, making up 50-70% of the egg weight. 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 on the local environment. 

   Although the Australian Brush-turkey is the only species of bird in which sex ratio is confirmed to be incubation-temperature dependent, it is speculated that this is common to all Megapodes, as they share nesting methods unique among birds. The non-social nature of their incubation raises questions as to how the hatchlings come to recognise other members of their species, which is due to imprinting in other members of the order Galliformes. Recent research suggests that there is an instinctive visual recognition of specific movement patterns made by the individual species of megapode.

Many are shy, solitary, and inconspicuous.

                                                

    The result is a low mound, about 1 m (3 feet) in the ground and up to 4.5 m across, consisting of leaves and twigs soaked with rain and covered with 0.5 m of sandy soil. When the heat of fermentation inside the mound reaches 33° C (91° F), the female lays the first of about 35 eggs in a central chamber. The male maintains a mound temperature astonishingly close to 33° C even in the face of daily and seasonal weather variation. 

The eggs hatch in seven weeks, and the hatchlings dig upward through the mound and run off on their own. They can fly one or two days after hatching.

Megapode chicks do not have an egg tooth: they use their powerful claws to break out of the egg, and then tunnel their way up to the surface of the mound, lying on their backs and scratching at the sand and vegetable matter. Similar to other superprecocial birds, they hatch fully feathered and active, already able to fly and live independently from their parents.