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

Taxonomic note
Blue-throated Hillstar, described by Sornoza-Molina et al. (2018), is accepted as a species diagnosable and scorable against O. stolzmanni on the Tobias criteria by its blue vs green throat in male (4); greener, brighter upperparts in male (1); dark greyish vs whitish base colour to chin and throat in female [see Sornoza-Molina et al. (2018) Appendix Figure 11] (1); slightly smaller size, albeit sample sizes are small (1). Monotypic.

Taxonomic source(s)
Handbook of the Birds of the World and BirdLife International. 2021. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 6. Available at: https://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v6_Dec21.zip.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
C2a(ii)	B1ab(ii,iii,v)+2ab(ii,iii,v); C2a(i,ii); D	B1ab(ii,iii,v)+2ab(ii,iii,v); C2a(i,ii); D1+2

Red List history

Year	Category	Criteria
2021	Critically Endangered	C2a(ii)
2016	Not Recognised
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	does not normally occur in forest
Land-mass type		Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	490 km2
Area of Occupancy (breeding/resident)	428 km2
Number of locations	3-5	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	80-110 mature individuals	good	estimated	2021
Population trend	decreasing	-	inferred	2018-2028
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	2.6 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The global population is extremely small. At the time of the species’s discovery, the global population was suspected to number below 750 individuals (Sornoza-Molina et al. 2018). During 25 consecutive surveys carried out in 2020 and 2021 throughout the known range, the population in Cerro de Arcos and Moras was estimated at 30-50 mature individuals, while in Guanazán and Burrourco the population was estimated at 30-40 mature individuals (Moens 2020; León et al. 2021; E. Bonaccorso et al. in litt. 2021). The population in Fierro Urco numbers at most 20 mature individuals (E. Bonaccorso et al. in litt. 2021), and there may be a small number of individuals in Chinchilla (J. Freile in litt. 2021). Based on these values, the total population may number 80-110 mature individuals.
The population structure has not been formally investigated. Observational records are localised, but fairly continuous within the distribution range (Sornoza-Molina et al. 2018; eBird 2021; León et al. 2021). Based on the very small size of the range, continuous distribution of observational records and absence of substantial barriers to dispersal, it is assumed that gene glow persists between individuals (H. M. Schaefer in litt. 2021; J. Freile in litt. 2021). Thus, the species is tentatively assessed as forming one subpopulation.

Trend justification: The species is strictly dependent on dense bushy stands, mainly of Chuquiraga jussieui, which are lost to ongoing habitat clearance through periodic burning of the paramo and degraded through cattle grazing and creation of pine plantations (Sornoza-Molina et al. 2018; Kirwan 2020; H. M. Schaefer in litt. 2021). Re-growth of Chuquiraga bushes is limited by droughts (Moens 2020); therefore, the vegetation may not recover sufficiently before the next fires are occurring. It is assumed that burning of the vegetation caused the species to disappear from two previously occupied sites near the Laguna de Chinchilla (E. Bonaccorso et al. in litt. 2021). The population is thus inferred to undergo a decline.Rates of habitat loss have not been quantified across the full range. However, it is reported that in Cerro de Arcos and Guanazán around 1 ha of suitable habitat has been lost over the past three years (León et al. 2021), which would roughly equate to a rate of 1% over three years. Assuming that this rate is representative for the entire range and continuing into the future, the total rate of habitat loss is roughly 3% over ten years. To account for uncertainty, it is here placed in the band 1-9% over ten years.

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

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Grassland	Subtropical/Tropical High Altitude	major	resident
Rocky areas (eg. inland cliffs, mountain peaks)		suitable	resident
Shrubland	Subtropical/Tropical High Altitude	major	resident
Altitude	3325 - 3680 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Small-holder farming	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Livestock farming & ranching - Small-holder grazing, ranching or farming	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation
Agriculture & aquaculture	Wood & pulp plantations - Small-holder plantations	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation
Climate change & severe weather	Droughts	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Slow, Significant Declines		Medium Impact: 7
		Stresses Indirect ecosystem effects, Ecosystem degradation
Energy production & mining	Mining & quarrying	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Rapid Declines		Low Impact: 5
		Stresses Ecosystem conversion
Human intrusions & disturbance	Recreational activities	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Causing/Could cause fluctuations		Low Impact: 5
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Aglaeactis cupripennis	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		No decline		Low Impact: 5
		Stresses Competition
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Falco femoralis	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		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, Ecosystem conversion, Species mortality

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Recommended citation
BirdLife International (2024) Species factsheet: Blue-throated Hillstar Oreotrochilus cyanolaemus. Downloaded from https://datazone.birdlife.org/species/factsheet/blue-throated-hillstar-oreotrochilus-cyanolaemus on 18/12/2024.
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 18/12/2024.