• 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
-	-	-

Red List history

Year	Category	Criteria
2021	Near Threatened	C2a(i)
2016	Near Threatened	C2a(i)
2012	Near Threatened	C2a(i)
2008	Near Threatened	C2a(i)
2007	Near Threatened
2004	Data Deficient
2000	Data Deficient
1994	Lower Risk/Near Threatened
1988	Near Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	27,600 km2	medium
Number of locations	11-100	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	4140 mature individuals	poor	estimated	2021
Population trend	decreasing	poor	inferred	2015-2027
Rate of change over the past 10 years/3 generations (longer of the two periods)	1-19%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	1-19%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	1-19%	-	-	-
Generation length	3.9 years	-	-	-
Number of subpopulations	3	-	-	-
Percentage of mature individuals in largest subpopulation	1-89%	-	-	-

Population justification: The species is thought to be generally rare, although it can be locally common and is possibly under-recorded (Cleere and Nurney 1998; Raffaele et al. 1998; Cleere and Sharpe 2020). Surveys at Las Cruces, Sierra de Bahoruco, in March 1996 revealed 4.5 individuals/km², essentially unchanged from 4.8 individuals/km² during surveys in the same area in 1976. Based on this density, and assuming that only 10% of the range are occupied to account for the species's rarity and apparent declines outside of the Sierra de Bahoruco (see eBird 2021), the total population is estimated at 6,210 individuals, equating to 4,140 mature individuals.

The population structure has not been investigated. Based on observational records (eBird 2021), it is tentatively assumed that the species forms at least three subpopulations in the south, the centre and the north of Hispaniola. Their sizes are unknown, but assuming a roughly equal size each subpopulation may number just above 1,000 mature individuals.

Trend justification: The species is thought to be declining at a slow to moderate rate, and it has apparently disappeared from parts of its range where it used to be common in the past, particularly in Haiti (Cleere and Sharpe 2020). Over the last three generations (11.7 years; Bird et al. 2020), 7% of tree cover has been lost in the range (Global Forest Watch 2021). The species is also suffering from low levels of predation by invasive mammals (S. Latta in litt. 2006; Cleere and Sharpe 2020). The rate of decline is therefore tentatively placed in the band 1-19% over three generations.

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

Country/Territory	IBA Name
Dominican Republic	Armando Bermudez National Park
Dominican Republic	Cabral Lagoon
Dominican Republic	Cotubanamá
Dominican Republic	Eastern Bahoruco
Dominican Republic	Enriquillo Lake National Park
Dominican Republic	Haitises National Park
Dominican Republic	Jaragua National Park
Dominican Republic	Sierra de Bahoruco National Park
Dominican Republic	Sierra de Neyba
Dominican Republic	Sierra Martin Garcia National Park

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Dry	major	resident
Shrubland	Subtropical/Tropical Dry	major	resident
Altitude	0 - 800 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Rapid Declines		Medium Impact: 7
		Stresses Ecosystem degradation, Ecosystem conversion
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Herpestes auropunctatus	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus norvegicus	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus rattus	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species mortality
Natural system modifications	Fire & fire suppression - Increase in fire frequency/intensity	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation

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Recommended citation
BirdLife International (2024) Species factsheet: Least Poorwill Siphonorhis brewsteri. Downloaded from https://datazone.birdlife.org/species/factsheet/least-poorwill-siphonorhis-brewsteri on 05/12/2024.
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 05/12/2024.