Introduction
The Maleo (Macrocephalon maleo) is a large megapode endemic to Sulawesi, Indonesia, with some range accounts also including nearby Buton Island. It is the only species in the genus Macrocephalon and is renowned for burying its eggs in naturally heated sand or soil rather than incubating them with body heat. Adults forage mainly in forest but travel to communal nesting grounds to breed. [1][2][3]
Physical Description
The Maleo is a chicken-sized, ground-dwelling bird measuring about 55 centimetres in length. Adults have blackish upperparts, pale salmon-pink to whitish underparts, bare yellow facial skin, a reddish-orange bill and a prominent dark, bony casque on the crown. The casque is present in both sexes, although its size and shape can vary between individuals. [2][4]
The species has strong legs and feet adapted for walking and digging. Maleo eggs are exceptionally large in relation to the size of the adult, weighing roughly five times as much as a domestic chicken egg in some measurements. The large egg contains substantial reserves that support the chick’s advanced development before hatching. [5]
Maleo chicks hatch fully feathered, with developed wings and feet. Unlike most newly hatched birds, they are not dependent on their parents for feeding or protection and can begin moving away from the nesting ground soon after reaching the surface. [1][3]
Range and Habitat
The Maleo is restricted to Sulawesi, where it occurs in suitable forest and nesting habitats across parts of the island. It is non-migratory, although adults make regular local movements between forest feeding areas and communal nesting grounds. Some accounts also recognise records from nearby Buton Island. [1][2]
Adults generally use primary and secondary lowland or hill forest, including riverine and swamp forest. They may forage from sea level to approximately 1,200 metres, although nesting grounds are usually in more open, warm locations. Important nesting sites include sunny beaches, lake shores, riverbanks and inland areas heated by hot springs or geothermal activity. [3][4]
The species depends on connections between forest and nesting grounds. When these corridors are cleared, degraded or obstructed, adults may have difficulty reaching suitable nesting sites and newly hatched chicks may be unable to reach forest habitat. [1][3]
Behaviour and Diet
Maleos are primarily diurnal and terrestrial. Adults often forage on the forest floor, feeding on fallen fruit, seeds and small invertebrates, including insects and snails. Their diet varies with local conditions and available food. [3][4]
Breeding takes place at communal nesting grounds. Pairs may gather near a site before selecting a suitable area, and both birds can participate in digging. A female lays a single large egg in a deep hole, which is then covered with sand or soil. The egg is incubated by solar heat or geothermal warmth, and the adults leave without providing further care. [1][3]
The incubation period is commonly reported as approximately 60 to 90 days, although it varies with the temperature and conditions of the nesting substrate. After hatching, the chick digs its way to the surface unaided. It emerges fully feathered and capable of flight, then disperses towards forest habitat without parental guidance. [1]
Identification Tips
Look for a large, chicken-sized bird with:
- Blackish upperparts contrasting with salmon-pink or pale underparts.
- Bare yellow facial skin and a reddish-orange bill.
- A distinctive dark, bony casque on the crown.
- Strong legs and a habit of walking through forest or open nesting areas rather than remaining in trees.
- Association with communal nesting grounds, especially warm beaches, riverbanks or geothermal soils.
The combination of the casque, black-and-pale plumage and salmon colouring is distinctive within the Maleo’s range. It should not be confused with more typical megapodes that build large composting mounds, because Maleos usually lay their eggs in buried chambers heated by the sun or geothermal activity. [2][3]
Conservation Status
The Maleo is currently classified as Critically Endangered. Its population has declined substantially, and many former nesting grounds have become inactive or support only very small numbers of birds. A range-wide assessment found that, between 1980 and 2019, 55 per cent of active nesting grounds became inactive, while most sites that remained active held fewer birds. [1]
The most significant immediate threat is the collection of eggs by people. Habitat loss and degradation also threaten the species, particularly where forests are cleared, nesting grounds are converted or the corridors linking nesting sites with forest are damaged. Other pressures can include disturbance, predation and local hunting. [1][3]
Effective conservation measures include protecting nesting grounds from egg-taking, maintaining forest corridors, securing habitat, monitoring sites and involving local communities in management. Studies from Sulawesi indicate that locally led protection of nesting grounds can increase Maleo numbers, particularly when communities help prevent egg poaching and protect adjacent forest. [3][6]
Frequently Asked Questions
Where does the Maleo live?
The Maleo lives in Sulawesi, Indonesia, and some records and range accounts include nearby Buton Island. Adults use forest habitat, while breeding takes place at warm, open nesting grounds such as beaches, riverbanks, lake shores and geothermal sites. [1][2]
How does the Maleo incubate its eggs?
The Maleo buries its eggs in warm sand or soil. Solar heat or geothermal warmth incubates the egg, so the adults do not need to sit on it. [1][3]
How large is a Maleo egg?
A Maleo egg is exceptionally large compared with the bird that lays it. Measurements reported in the literature indicate that it can weigh about five times as much as a domestic chicken egg. [5]
Do Maleo parents care for their chicks?
No. After the egg is buried, the adults leave the nesting ground. The chick hatches fully feathered, digs to the surface and disperses without parental feeding or protection. [1][3]
What does the Maleo eat?
Maleos forage mainly on the forest floor and eat a mixture of fallen fruit, seeds and small invertebrates such as insects and snails. [3][4]
Why is the Maleo endangered?
The principal threats are the collection of eggs, loss and degradation of forest, damage to nesting grounds and the loss of corridors linking nesting sites with suitable forest. Community-based protection of nesting grounds is an important part of current conservation work. [1][3][6]
References
- [1] BirdLife International. 2025. Species factsheet: Maleo, Macrocephalon maleo. BirdLife International Data Zone. https://datazone.birdlife.org/species/factsheet/maleo-macrocephalon-maleo. Accessed 8 September 2026.
- [2] Gill, F., Donsker, D. and Rasmussen, P., eds. 2026. IOC World Bird List, version 15.2. International Ornithologists’ Committee. https://www.worldbirdnames.org/new/. Accessed 8 September 2026.
- [3] Summers, M., Geary, M., Tasirin, J. S., Djuni, N., Summers, L. J., Kresno, P. A., Laya, A., Sawuwu, S. M., Bawotong, A., Abas, W., Oga, V. T., Nur, A. M., Isfandri, M., Robertson, P., McGowan, P. J. K. and Collar, N. J. 2025. Massive declines and local recoveries: First range-wide assessment spotlights ending egg-taking as key to the survival of Macrocephalon maleo (Maleo). Ornithological Applications, 127, duaf022. https://doi.org/10.1093/ornithapp/duaf022.
- [4] Baker, G. C. and Butchart, S. H. M. 2000. Priority sites for conservation of maleos, Macrocephalon maleo, in central Sulawesi. Biological Conservation, 94(1), 79-91. https://doi.org/10.1016/S0006-3207(99)00161-5.
- [5] Rudiah, R. 2017. Physical comparative and nutritive characteristics of Maleo eggs. International Seminar on Tropical Animal Production proceedings, Universitas Gadjah Mada. https://journal.ugm.ac.id/istapproceeding/article/view/32571. Accessed 8 September 2026.
- [6] Tasirin, J. S., Iskandar, D. T., Laya, A., Kresno, P., Sawuwu, S., Bawotong, A., Abas, W., Oga, V. M. T., Nur, A. M., Isfandri, M., Geary, M., Summers, M., McGowan, P. J. K. and Collar, N. J. 2021. Maleo Macrocephalon maleo population recovery at two Sulawesi nesting grounds after community engagement to prevent egg poaching. Global Ecology and Conservation, 28, e01699. https://doi.org/10.1016/j.gecco.2021.e01699.
- [7] Summers, M., Geary, M., Djuni, N., Kresno, P. A., Laya, A., Sawuwu, S., Bawotong, A., Abas, W., Oga, V. M. T., Nur, A. M., Isfandri, M., Priest, G. V., McGowan, P. J. K., Tasirin, J. S. and Collar, N. J. 2023. Degree of egg-taking by humans determines the fate of Maleo, Macrocephalon maleo, nesting grounds across Sulawesi. Biodiversity and Conservation, 32, 899-919. https://doi.org/10.1007/s10531-022-02527-1.
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