Mound-builders
Encyclopedia
The megapodes, also known as incubator birds or mound-builders, are stocky, medium-large chicken-like bird
s with small heads and large feet in the family Megapodiidae. Their name literally means large foot (Greek
: mega = large, poda = foot), and is a reference to the heavy legs and feet typical of these terrestrial
birds. 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 same day they hatch.
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 Brushturkey 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.
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.
, 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
. The distribution of the family has contracted in the Pacific with the arrival of humans, and a number of island groups such as Fiji
, Tonga
and New Caledonia
have lost many or all of their species.
FAMILY: MEGAPODIIDAE
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s with small heads and large feet in the family Megapodiidae. Their name literally means large foot (Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
: mega = large, poda = foot), and is a reference to the heavy legs and feet typical of these terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
birds. All are browsers
Browsing (predation)
Browsing is a type of herbivory in which an herbivore feeds on leaves, soft shoots, or fruits of high growing, generally woody, plants such as shrubs. This is contrasted with grazing, usually associated with animals feeding on grass or other low vegetation...
, all but the Malleefowl
Malleefowl
The Malleefowl is a stocky ground-dwelling Australian bird about the size of a domestic chicken...
occupy wooded habitats, and most are brown or black colored. Megapodes are superprecocial
Superprecocial
The term superprecocial refers to a level of physical maturity and capability in young animals that is most extreme. Examples are the Megapode birds, which have full flight feathers and which, in some species, can fly on the same day they hatch from their eggs...
, 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 same day they hatch.
Breeding and nests
Temperature-dependent sex determination
Temperature-dependent sex determination is type of environmental sex determination in which the temperatures experienced during embryonic development determine the sex of the offspring. It is most prevalent and common among amniote vertebrates that are classified under the reptile class, but is...
, 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
Imprinting (psychology)
Imprinting is the term used in psychology and ethology to describe any kind of phase-sensitive learning that is rapid and apparently independent of the consequences of behavior...
in other members of the order Galliformes
Galliformes
Galliformes are an order of heavy-bodied ground-feeding domestic or game bird, containing turkey, grouse, chicken, New and Old World Quail, ptarmigan, partridge, pheasant, and the Cracidae. Common names are gamefowl or gamebirds, landfowl, gallinaceous birds or galliforms...
. 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.
Megapode chicks do not have an egg tooth
Egg tooth
In some egg-laying animals, the egg tooth is a small, sharp, cranial protuberance used by offspring to break or tear through the egg's surface during hatching...
: 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
Superprecocial
The term superprecocial refers to a level of physical maturity and capability in young animals that is most extreme. Examples are the Megapode birds, which have full flight feathers and which, in some species, can fly on the same day they hatch from their eggs...
birds, they hatch fully feathered and active, already able to fly and live independently from their parents.
Distribution
Megapodes are found in the broader Australasian region, including islands in the western PacificPacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...
, and the islands of Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
east of the Wallace Line
Wallace Line
The Wallace Line separates the ecozones of Asia and Wallacea, a transitional zone between Asia and Australia. West of the line are found organisms related to Asiatic species; to the east, a mixture of species of Asian and Australian origin is present...
, but also the Andaman
Andaman Islands
The Andaman Islands are a group of Indian Ocean archipelagic islands in the Bay of Bengal between India to the west, and Burma , to the north and east...
and Nicobar Islands
Nicobar Islands
The Nicobar Islands are an archipelagic island chain in the eastern Indian Ocean...
in the Bay of Bengal
Bay of Bengal
The Bay of Bengal , the largest bay in the world, forms the northeastern part of the Indian Ocean. It resembles a triangle in shape, and is bordered mostly by the Eastern Coast of India, southern coast of Bangladesh and Sri Lanka to the west and Burma and the Andaman and Nicobar Islands to the...
. The distribution of the family has contracted in the Pacific with the arrival of humans, and a number of island groups such as Fiji
Fiji
Fiji , officially the Republic of Fiji , is an island nation in Melanesia in the South Pacific Ocean about northeast of New Zealand's North Island...
, Tonga
Tonga
Tonga, officially the Kingdom of Tonga , is a state and an archipelago in the South Pacific Ocean, comprising 176 islands scattered over of ocean in the South Pacific...
and New Caledonia
New Caledonia
New Caledonia is a special collectivity of France located in the southwest Pacific Ocean, east of Australia and about from Metropolitan France. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre, the Loyalty Islands, the Belep archipelago, the Isle of...
have lost many or all of their species.
Species
There are more than 20 species in 7 genera. Although the evolutionary relationships between the Megapodiidae are especially uncertain, the morphological groups are clear:FAMILY: MEGAPODIIDAE
- Scrubfowl groupScrubfowlThe scrubfowl are the genus Megapodius of the mound-builders, stocky, medium-large chicken-like birds with small heads and large feet in the family Megapodiidae. They are found from south-east Asia to north Australia and islands in the west Pacific.They do not incubate their eggs with their body...
- Genus: Macrocephalon
- MaleoMaleoThe Maleo is a medium-sized blackish megapode with bare yellow facial skin, reddish-brown iris, reddish-orange beak and rosy salmon underparts. The crown is ornamented with a black helmet casque. The greyish blue feet have four long sharp claws, separated by a membranous web...
, Macrocephalon maleo
- Maleo
- Genus: Eulipoa (sometimes included in Megapodius)
- Moluccan MegapodeMoluccan MegapodeThe Moluccan Megapode also known as Wallace's Scrubfowl, Moluccan Scrubfowl or Painted Megapode, is a small, approximately 31 cm long, olive-brown megapode. The genus Eulipoa is monotypic, but the Moluccan Megapode is sometimes placed in Megapodius instead...
, Eulipoa wallacei.
- Moluccan Megapode
- Genus: Megapodius
- Tongan Megapode, Megapodius pritchardii
- Micronesian MegapodeMicronesian MegapodeThe Micronesian Megapode or Micronesian Scrubfowl, Megapodius laperouse, is an endangered megapode which inhabits islands of the Western Pacific Ocean.-Description:...
, Megapodius laperouse- Marianas Island Megapode, Megapodius laperouse laperouse
- Palau Island Megapode, Megapodius laperouse senex
- Nicobar Megapode, Megapodius nicobariensis
- Philippine Megapode, Megapodius cumingii
- Sula Megapode, Megapodius bernsteinii
- Tanimbar Megapode Megapodius tenimberensis
- Dusky Megapode, Megapodius freycinet
- Forsten's Megapode, Megapodius (freycinet) forstenii
- Biak Scrubfowl Megapodius geelvinkianus
- Melanesian Megapode, Megapodius eremita
- Vanuatu MegapodeVanuatu MegapodeThe Vanuatu Megapode or Vanuatu Scrubfowl is a species of bird in the Megapodiidae family. It was formerly known as the New Hebrides Scrubfowl.It is found only in Vanuatu....
, Megapodius layardi - New Guinea ScrubfowlNew Guinea ScrubfowlThe New Guinea Scrubfowl is a species of bird in the Megapodiidae family.It is found in Indonesia and Papua New Guinea....
, Megapodius affinis - Orange-footed ScrubfowlOrange-footed ScrubfowlThe Orange-footed Scrubfowl, Megapodius reinwardt, is a small megapode of the family Megapodiidae.This species comprises five subspecies found on many islands in Wallacea as well as southern New Guinea and northern Australia. It is a terrestrial bird the size of a domestic chicken and dark-coloured...
Megapodius reinwardt - †Pile-builder Scrubfowl Megapodius molistructor
- Genus: Macrocephalon
- MalleefowlMalleefowlThe Malleefowl is a stocky ground-dwelling Australian bird about the size of a domestic chicken...
group- Genus: Leipoa
- MalleefowlMalleefowlThe Malleefowl is a stocky ground-dwelling Australian bird about the size of a domestic chicken...
, Leipoa ocellata
- Malleefowl
- Genus: Leipoa
- Brushturkey groupBrushturkeyBrushturkeys are a group of birds in 3 genera in the Megapode family. The species are as follows:* Genus: Alectura** Australian Brushturkey, Alectura lathami* Genus: Aepypodius** Wattled Brushturkey, Aepypodius arfakianus...
- Genus: Alectura
- Australian Brushturkey, Alectura lathami
- Genus: AepypodiusAepypodiusAepypodius is a genus of birds in the Megapodiidae family.It contains the following species:* Wattled Brushturkey * Waigeo Brushturkey,...
- Wattled Brushturkey, Aepypodius arfakianus
- Waigeo Brushturkey, Aepypodius bruijnii
- Genus: TalegallaTalegallaTalegalla is a genus of bird in the Megapodiidae family.It contains the following species:* Red-billed Brushturkey * Black-billed Brushturkey * Collared Brushturkey...
- Red-billed Brushturkey, Talegalla cuvieri
- Black-billed Brushturkey, Talegalla fuscirostris
- Collared Brushturkey, Talegalla jobiensis
- Genus: Alectura
External links
- Mound-builders videos, photos & sounds on the Internet Bird Collection
- Photograph of a nest mound of M. tenimberensis from the Oriental Bird Club