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

Taxonomic note
Hydrobates hornbyi (del Hoyo and Collar 2014) was previously placed in the genus Oceanodroma.

Taxonomic source(s)
Brooke, M. de L. 2004. Albatrosses and Petrels Across the World. Oxford University Press, Oxford.
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.
SACC. 2005 and updates. A classification of the bird species of South America. Available at: #http://www.museum.lsu.edu/~Remsen/SACCBaseline.htm#.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2019	Near Threatened	B2b(iii)
2018	Data Deficient
2016	Data Deficient
2012	Data Deficient
2010	Data Deficient
2008	Data Deficient
2004	Data Deficient
2000	Data Deficient
1996	Data Deficient
1994	Data Deficient
1988	Threatened

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 (km2)	2,560,000	medium
Extent of Occurrence breeding/resident (km2)	2,000
Number of locations		-
Severely Fragmented		-

	Value	Data quality	Derivation	Year of estimate
No. of mature individuals	500000-800000	medium	estimated	2007
Population trend	Decreasing		suspected	-
Decline (3 years/1 generation past)		-	-	-
Decline (5 years/1 generation past)		-	-	-
Decline (10 years/1 generation past)		-	-	-
Decline (10 years/3 generation future)		-	-	-
Decline (10 years/3 generation past and future)		-	-	-
Number of subpopulations		-	-	-
Percentage in largest subpopulation		-	-	-
Generation length (yrs)	16	-	-	-

Population justification: Brooke (2004) suspected the global population to number at least thousands of individuals, and probably tens of thousands. Marine surveys in the 1980s-1990s led to an estimated abundance of 637,200 in spring (95% CI: 0.5-0.8 million) and 1,011,900 in autumn (95% CI: 900,000-1,500,000) (Spear and Ainley 2007). Assuming the lower population estimates in spring represent mature individuals, we can derive from these surveys a population estimate of 500,000-800,000 mature individuals. The subpopulation structure is not known.

Trend justification: The species may be declining as a result of threats, including light pollution, but we have no data from which to quantify population trends.

Country/Territory	Occurrence status	Presence	Resident	Breeding	Non-breeding	Passage
Chile	N	Extant	Yes
Ecuador	N	Extant	Yes
Peru	N	Extant	Yes

Country/Territory	IBA Name
Peru	Reserva Nacional de Paracas
Peru	Río Tambo y Lagunas de Mejía

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Desert	Cold	major	breeding
Marine Neritic	Macroalgal/Kelp	suitable	resident
Marine Neritic	Pelagic	major	resident
Marine Neritic	Seagrass (Submerged)	suitable	resident
Marine Neritic	Subtidal Loose Rock/pebble/gravel	suitable	resident
Marine Neritic	Subtidal Rock and Rocky Reefs	suitable	resident
Marine Neritic	Subtidal Sandy	suitable	resident
Marine Neritic	Subtidal Sandy-Mud	suitable	resident
Marine Oceanic	Epipelagic (0-200m)	major	resident
Marine Oceanic	Mesopelagic (200-1000m)	major	resident
Altitude		Occasional altitudinal limits	(max) 3400 m

Threat (level 1)	Threat (level 2)	Impact and Stresses
Energy production & mining	Mining & quarrying	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion
Energy production & mining	Renewable energy	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion
Pollution	Excess energy - Light pollution	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Reduced reproductive success, Species mortality
Transportation & service corridors	Roads & railroads	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion
Transportation & service corridors	Utility & service lines	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2021) Species factsheet: Hydrobates hornbyi. Downloaded from http://www.birdlife.org on 19/10/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/10/2021.