• 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
-	-	A3cd+4cd

Red List history

Year	Category	Criteria
2021	Vulnerable	A3cd+4cd
2016	Vulnerable	A2cd+3cd+4cd
2012	Vulnerable	A2cd+3cd+4cd
2008	Vulnerable	A2c,d; A3c,d; A4c,d
2004	Vulnerable
2000	Vulnerable
1994	Lower Risk/Least Concern
1988	Lower Risk/Least Concern

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	41,300 km2	medium

	Estimate	Data quality	Derivation	Year of estimate
Population size	20000-49999 mature individuals	medium	inferred	2021
Population trend	decreasing	poor	inferred	2016-2039
Rate of change over the past 10 years/3 generations (longer of the two periods)	15-25%	-	-	-
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)	30-49%	-	-	-
Generation length	7.6 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: A 2006 survey in Puerto Princesa Subterranean River National Park, the species was recorded at densities of 19.6 individuals/km² in old growth forest; 13.8 in advanced growth secondary forest; and 9.6  individuals/km² in early secondary growth; it was absent from cultivated areas (Mallari et al. 2011). The species has also been recorded in tree-dominated agricultural areas (Widmann et al. 2015). Using the densities they estimated and land cover data from 2000, Mallari et al. (2011) predicted there could be a maximum of 59,000 individuals in old growth forest alone. Their data allow for further extrapolations of 58,000-84,000 additional birds in second growth, equivalent to a total population of 77,000-94,000 mature individuals. However, Puerto Princesa Subterranean River National Park is protected and rates of hunting are likely to be lower here, and these extrapolations assume complete and even occupancy. Accounting for habitat loss since 2000, habitat fragmentation effects, likely hunting pressures outside the National Park, uneven occupancy rates and this species's reliance on hollows for nesting, a more precautionary population size of 20,000-50,000 mature individuals is suspected.

Trend justification: Between 2016 and 2020, forest loss in this species's range has averaged c.1.4% per annum, projected to c.31% over the next three generations (Global Forest Watch 2021). Although this species can tolerate forest degradation (Malleri et al. 2011), it is absent entirely from cultivation which continues to expand on Palawan. The impact of hunting is unquantified but is assumed to be high outside protected areas since this is the only hornbill on the island. The impact of these threats is predicted to accelerate with Palawan's increasing human population (PSA 2015) and the rate of population reduction is therefore projected to be 30-49% over the current and future three-generation periods.

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

Country/Territory	IBA Name
Philippines	Balabac Island
Philippines	Busuanga Island
Philippines	Calauit Island
Philippines	Culion Island
Philippines	El Nido
Philippines	Mount Mantalingahan
Philippines	Puerto Princesa Subterranean River Natural Park / Cleopatra's Needle
Philippines	San Vicente - Taytay - Roxas forests
Philippines	Victoria and Anepahan Ranges

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Arable Land	marginal	resident
Forest	Subtropical/Tropical Mangrove Vegetation Above High Tide Level	suitable	non-breeding
Forest	Subtropical/Tropical Moist Lowland	major	resident
Altitude	0 - 900 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Reduced reproductive success, Species mortality
Biological resource use	Logging & wood harvesting - Unintentional effects: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion, Reduced reproductive success
Energy production & mining	Mining & quarrying	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion

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

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Recommended citation
BirdLife International (2024) Species factsheet: Palawan Hornbill Anthracoceros marchei. Downloaded from https://datazone.birdlife.org/species/factsheet/palawan-hornbill-anthracoceros-marchei 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.