Megapode


Megapode
Megapodiidae
Australian Brushturkey (Alectura lathami)
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. 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.[1]

Contents

Breeding and nests

Australian Brushturkey on its mound.
Cross section of a Megapode mound, showing layer of sand (up to 1 m thick) used for insulation; egg chamber; and layer of rotting compost. The egg chamber is kept at a constant 33°C by opening and closing air vents in the insulation layer, while heat comes from the compost below.

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.[2] 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.[3] 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.[4] 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.[5]

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.[2]

Distribution

Brushturkeys can often be found in parks or gardens

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. 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.[3]

Species

‎There are more than 20 species in 7 genera. Although the evolutionary relationships between the Megapodiidae are especially uncertain[citation needed], the morphological groups are clear:[6]

FAMILY: MEGAPODIIDAE

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. ^ a b Starck, JM & SUtter E (2000) Patterns of growth and heterochrony in moundbuilders (MEgapodiidae) and fowl (Phasianidae). J. Avian Biol. 31:527-547
  3. ^ a b Steadman D, (2006). Extinction and Biogeography in Tropical Pacific Birds, University of Chicago Press. ISBN 978-0-226-77142-7
  4. ^ Göth, A. & D.T. Booth. (2005) "Temperature-dependent sex ratio in a bird." Biol. Lett. 1(1):31-3.
  5. ^ 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
  6. ^ Birks, S. M., and S. V. Edwards. 2002. A phylogeny of the megapodes (Aves: Megapodiidae) based on nuclear and mitochondrial DNA sequences. Molecular Phylogenetics and Evolution 23: 408-421.

External links


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Look at other dictionaries:

  • Megapode — Meg a*pode (m[e^]g [.a]*p[=o]d), n. [Mega + Gr. poy s, podo s, foot.] (Zo[ o]l.) Any one of several species of large footed, gallinaceous birds of the genera {Megapodius} and {Leipoa}, inhabiting Australia and other Pacific islands. Called also… …   The Collaborative International Dictionary of English

  • mégapode — ● mégapode nom masculin Gros oiseau galliforme des régions tropicales de l Indo Pacifique qui assure l incubation de ses œufs en recourant à la chaleur solaire, volcanique ou à celle provenant de la fermentation contrôlée de substances organiques …   Encyclopédie Universelle

  • megapode — [meg′əpōd΄] n. [see MEGAPOD] any of a family (Megapodiidae) of large footed, ground dwelling gallinaceous birds of Australia and the East Indies that bury their eggs, often in mounds they have built of earth and vegetation …   English World dictionary

  • Mégapode — Megapodiidae Mégapodiidés …   Wikipédia en Français

  • megapode — moundbird moundbird, mound bird mound bird . (Zo[ o]l.) Any of several large footed short winged birds of Australasia, which build mounds of decaying vegetation to incubate eggs. Called also {mound builder}, {mound maker}, {megapode}, {brush… …   The Collaborative International Dictionary of English

  • megapode — didžiakojės vištos statusas T sritis zoologija | vardynas atitikmenys: lot. Megapodius angl. megapode rus. большеног, m pranc. mégapode, m ryšiai: platesnis terminas – didžiakojiniai siauresnis terminas – Bernšteino didžiakojė višta siauresnis… …   Paukščių pavadinimų žodynas

  • mégapode — didžiakojės vištos statusas T sritis zoologija | vardynas atitikmenys: lot. Megapodius angl. megapode rus. большеног, m pranc. mégapode, m ryšiai: platesnis terminas – didžiakojiniai siauresnis terminas – Bernšteino didžiakojė višta siauresnis… …   Paukščių pavadinimų žodynas

  • megapode — /meg euh pohd /, n. any of several large footed, short winged gallinaceous Australasian birds of the family Megapodiidae, typically building a compostlike mound of decaying vegetation as an incubator for their eggs. Also called brush turkey,… …   Universalium

  • megapode — 1. noun Any of several chicken or turkey like birds in the family Megapodiidae, which incubate their eggs by burying them where they receive warmth from decaying vegetation, solar radiation or geothermal heat. Syn: brush turkey, incubator bird,… …   Wiktionary

  • megapode — me·gà·po·de s.m. TS ornit. uccello del sottordine dei Megapodi | pl. con iniz. maiusc., sottordine dell ordine dei Galliformi {{line}} {{/line}} DATA: 1834. ETIMO: dal lat. scient. Megapodii, vd. mega e pode …   Dizionario italiano