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

Taxonomic note
Ceyx lepidus, C. margarethae, C. wallacii, C. cajeli, C. solitarius, C. dispar, C. mulcatus, C. sacerdotis, C. meeki, C. collectoris, C. nigromaxilla and C. gentianus (del Hoyo and Collar 2014) were previously lumped as C. lepidus following Sibley and Monroe (1990, 1993).

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
-	-	D1

Red List history

Year	Category	Criteria
2022	Near Threatened	B1b(ii,iii); C2a(ii)
2016	Near Threatened	C2a(ii)
2014	Near Threatened	C2a(ii)
2012	Not Recognised
2008	Not Recognised
2004	Not Recognised
2000	Not Recognised
1994	Not Recognised
1988	Not Recognised

Migratory status	not a migrant	Forest dependency	medium
Land-mass type		Average mass	19 g

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	13,300 km2
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	580-5800, 2500-5000 mature individuals	poor	inferred	2020
Population trend	decreasing	-	suspected	2016-2026
Rate of change over the past 10 years/3 generations (longer of the two periods)	1-9%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	1-9%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	1-9%	-	-	-
Generation length	2.9 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: No species-specific population estimate has been generated for the species. Other Ceyx species have been recorded at densities of 2–10 birds/km² (Bell 1982, Vernon 1985). In 2020, there was approximately 4,400 km² of forest (excluding plantations) left in the species' range (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein). Assuming C. wallacii occurs at similar densities to other Ceyx and that approximately 10–20% of suitable habitat is occupied (a reflection of its apparently being quite common; F. Rheindt in litt. 2020), the population likely numbers 880–8,800, or 580–5,800 mature individuals. Given field observations, a best estimate of 2,500–5,000 mature individuals is suspected.

Trend justification: Forest loss in this species' range is equivalent to c.5–8% over ten years (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein). Because it requires some element of forested habitat to persist (i.e. it does not occur in agricultural areas and has not been recorded in plantations) but is at least partially tolerant of degradation, there is uncertainty in the extent to which a decline in forest cover reflects a decline in the population of this species. To account for these uncertainties, the population is suspected of having declined 1–9% over the past 10 years and, with no likely abatement in forest loss, this rate is projected into the future.

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

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Shrubland	Subtropical/Tropical Moist	suitable	resident
Wetlands (inland)	Permanent Rivers/Streams/Creeks (includes waterfalls)	suitable	resident
Altitude	0 - 500 m	Occasional altitudinal limits	(max) 1300 m

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
Agriculture & aquaculture	Wood & pulp plantations - Agro-industry plantations	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
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

---

Recommended citation
BirdLife International (2024) Species factsheet: Sula Dwarf-kingfisher Ceyx wallacii. Downloaded from https://datazone.birdlife.org/species/factsheet/sula-dwarf-kingfisher-ceyx-wallacii on 22/12/2024.
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 22/12/2024.