• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
A2cd+4cd	A2cd+4cd	A2cd+3cd+4cd; C2a(i)

Red List history

Year	Category	Criteria
2021	Critically Endangered	A2cd+4cd
2016	Endangered	A2bcde+3bcde+4bcde
2013	Endangered	A2bcde+3bcde+4bcde
2012	Endangered	A2bcde+3bcde+4bcde
2008	Endangered	A2b,c,d,e; A3b,c,d,e; A4b,c,d,e
2007	Endangered
2004	Endangered
2002	Endangered
2000	Vulnerable
1996	Vulnerable
1994	Vulnerable
1988	Threatened

Migratory status	not a migrant	Forest dependency	high
Land-mass type		Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	373,000 km2	medium
Number of locations	48	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	8000-14000 mature individuals	medium	estimated	2000
Population trend	decreasing	good	inferred	1990-2022
Rate of change over the past 10 years/3 generations (longer of the two periods)	80-95,87%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	30-49%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	80-90%	-	-	-
Generation length	10.8 years	-	-	-
Number of subpopulations	2-100	-	-	-
Percentage of mature individuals in largest subpopulation	1-89%	-	-	-

Population justification: The total population is estimated to number 4,000-7,000 breeding pairs (Butchart & Baker 2000), equivalent to 8,000-14,000 mature individuals or 12,000-21,000 individuals in total. Despite numerous research projects at multiple nesting grounds since, a coordinated resurvey has only recently been undertaken which initial findings appear to confirm the continuation of a rapid decline (Alliance for Tompotika Conservation 2018).Very few nesting sites are considered secure: intact, connected to forest habitat and safe from egg collection (Dekker 1990). Where there is long-term conservation commitment numbers of individuals can increase rapidly: at Taima 
The key areas holding the largest proportions of the population are the 'Bogani Landscape' around Bogani Nani Wartabone National Park plus Tanjung Dako and Tanjung Matop areas along the coast in North Sulawesi (Argeloo 1994, Butchart & Baker 2000, Gorog et al. 2005), while in Central Sulawesi key sites are Lore Lindu National Park (Butchart & Baker 2000), Morowali Nature Reserve and nearby Sungai Bosu, and three sites on the eastern peninsular (Bakiriang, Libuun and Pintu Kubur) in Central Sulawesi (Butchart & Baker 2000). 

Most information pertains to sites in the 'Bogani Landscape' in North Sulawesi. Here, 50% of known nesting grounds (18/36) were assessed as having been abandoned by 2003, and five of the 27 sites also assessed in 1990-1991 had been active at that time (Gorog et al. 2005). Six further nesting grounds were predicted to have a high likelihood of abandonment in the near future (Gorog et al. 2005). One of these sites, Tanjung Binereang, has been the subject of a significant conservation project involving the creation of a private locally-owned reserve that has been successful at preventing abandonment (Clements 2009). Sites within protected areas were more likely to persist and in the absence of direct intervention through guarding the nesting grounds abandonment was likely: 17/26 nesting grounds in non-protected areas assessed in 2003 had already been abandoned and of the remainder 6 were 'Severely Threatened' and two (adjacent to each other) were threatened (Gorog et al. 2005).

Numbers of individuals is difficult to assess, as pairs arrive intermittently at the breeding ground and females lay their estimated annual clutch of 8-12 eggs  (Dekker 1990) over a variable time period. At Saluki, one of the main nesting grounds in Lore Lindu National Park, 162 mature individuals were estimated from maximum monthly number of eggs laid during a 6-month study in 2015, contrasted with an estimate of 325-650 for the site in 2001 (Yanto Samana 2015). However Butchart & Baker (2000) roughly estimated 10-50 pairs at the site in 2000, 20-100 mature individuals. Both works indicate a strong decrease has occurred, evidenced by the dramatic reduction in numbers of eggs harvested from over 30 daily in the early 1980s to only 1-2 a day by 1999 (Butchart & Baker 2000). Action to conserve this population has clearly prevented the abandonment of the site (Yanto Samana 2015).

Trend justification: Maximum daily numbers of individuals visiting nesting grounds have declined by more than 80% over the past three generations (Summers et al., in prep). These numbers are inferred to directly relate to the total size of the population.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Indonesia	extant	native	yes

Country/Territory	IBA Name
Indonesia	Bogani Nani Wartabone
Indonesia	Buton Utara
Indonesia	Feruhumpenai - Matano
Indonesia	Lore Lindu
Indonesia	Morowali
Indonesia	Pasoso
Indonesia	Rawa Aopa Watumohai
Indonesia	Tangkoko Dua Sudara

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Mangrove Vegetation Above High Tide Level	marginal	resident
Forest	Subtropical/Tropical Moist Lowland	major	resident
Forest	Subtropical/Tropical Moist Montane	major	resident
Marine Intertidal	Sandy Shoreline and/or Beaches, Sand Bars, Spits, Etc	major	breeding
Wetlands (inland)	Permanent Freshwater Lakes (over 8ha)	suitable	resident
Wetlands (inland)	Permanent Freshwater Marshes/Pools (under 8ha)	suitable	resident
Altitude	0 - 1065 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Agro-industry farming	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Annual & perennial non-timber crops - Small-holder farming	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Very Rapid Declines		High Impact: 8
		Stresses Reduced reproductive success, Species mortality
Biological resource use	Logging & wood harvesting - Unintentional effects: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Energy production & mining	Mining & quarrying	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Human intrusions & disturbance	Work & other activities	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Species disturbance
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Canis familiaris	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Unknown		Unknown
		Stresses Species disturbance, Species mortality
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Named species	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Unknown		Unknown
		Stresses Species disturbance, Species mortality
Natural system modifications	Fire & fire suppression - Increase in fire frequency/intensity	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion
Residential & commercial development	Housing & urban areas	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation, Ecosystem conversion
Transportation & service corridors	Roads & railroads	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation, Ecosystem conversion

Purpose	Scale
Food - human	subsistence, national
Other household goods	subsistence, national
Pets/display animals, horticulture	international
Sport hunting/specimen collecting	subsistence, national

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Recommended citation
BirdLife International (2024) Species factsheet: Maleo Macrocephalon maleo. Downloaded from https://datazone.birdlife.org/species/factsheet/maleo-macrocephalon-maleo on 22/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 22/11/2024.