Megapode

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For other uses of the term "mound builder", see Mound builder.
Megapodiidae
Micronesian Scrubfowl
Micronesian Scrubfowl
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Galliformes
Family: Megapodiidae
Lesson, 1831
Genera

The megapodes, also known as incubator birds or mound-builders, are stocky, medium-large chicken-like birds with small heads and large feet in the family Megapodiidae. They are terrestrial browsers. All but the Malleefowl occupy jungle habitats, and most are brown or black coloured. Megapodes are called superprecocial, which means that they hatch 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 same day they hatch.[1]

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[edit] Breeding and nests

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[citation needed]. 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[2]. The non-social nature of their incubation raises questions as to how the hatchlings come to recognise other members of their species, a process subserved by imprinting in other members of the order Galliformes; recent research suggests that there is an instinctive visual recognition of specific movement patterns of conspecifics.[3]

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 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 precocious birds, they hatch fully feathered and active, already able to fly and live independent from their parents.

[edit] Distribution

Megapodes are found 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.

[edit] Species

There are 21 species in 6 genera. Although the evolutionary relationships between the Megapodiidae are especially uncertain[citation needed], the morphological groups are clear:

[edit] References

  1. ^ Starck, J.M., Ricklefs, R.E.(1998) "Avian Growth and Development. Evolution within the altricial precocial spectrum." Oxford University Press, New York, 1998.
  2. ^ Göth, A. & D.T. Booth. (2005) "Temperature-dependent sex ratio in a bird." Biol. Lett. 1(1):31-3.
  3. ^ Göth, A., & Evans, C. S. (2004). Social responses without early experience: Australian brush-turkey chicks use specific visual cues to aggregate with conspecifics. Journal of Experimental Biology, 207, 2199-2208. doi:10.1242/jeb.01008

[edit] External links