Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Procellariiformes Hydrobatidae

Scientific Name: Hydrobates hornbyi
Species Authority: (G.R. Gray, 1864)
Common Name(s):
English Ringed Storm-petrel, Hornby's Storm Petrel, Ringed Storm-Petrel
Oceanodroma hornbyi (G.R. Gray, 1864)
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. Lynx Edicions BirdLife International.
Taxonomic Notes: Hydrobates hornbyi (del Hoyo and Collar 2014) was previously placed in the genus Oceanodroma.

Assessment Information [top]

Red List Category & Criteria: Data Deficient ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Facilitator/Compiler(s): Benstead, P., Isherwood, I., Sharpe, C J & Symes, A.
Data on where the species breeds and hence threats and population trends are lacking.
Previously published Red List assessments:
2010 Data Deficient (DD)
2008 Data Deficient (DD)
2004 Data Deficient (DD)
2000 Data Deficient (DD)
1996 Data Deficient (DD)
1994 Data Deficient (DD)
1988 Threatened (T)

Geographic Range [top]

Range Description: Hydrobates hornbyi has been observed in thousands in the eastern Pacific Ocean, along the coast of Peru and Chile (Carboneras 1992c). Data on overall numbers and trends are lacking, and the breeding grounds have never been found (Carboneras 1992c, Brooke 1999, 2000). At-sea distribution and observations of grounded birds indicate that it nests between 20° and 25°S in Chile and perhaps north into Peru (Brooke 1999). Birds may breed on offshore islands or mainland cliffs, but the coast of north Chile is distinctly bereft of islands and the cliffs are largely devoid of deep rocky crevices or soil in which petrels might burrow (Brooke 1999). It is most likely to nest in the Atacama Desert, and there are reports of mummified adults and fledglings found up to 50 km inland and 1,500 m above sea level (Tobias et al. 2006).

Countries occurrence:
Chile; Peru
Colombia; United States
Present - origin uncertain:
Continuing decline in area of occupancy (AOO): Unknown
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 201000
Continuing decline in extent of occurrence (EOO): Unknown
Extreme fluctuations in extent of occurrence (EOO): No
Continuing decline in number of locations: Unknown
Extreme fluctuations in the number of locations: No
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Brooke (2004) estimated the global population to number at least thousands of individuals (possibly up to tens of thousands of individuals). It is thus estimated to range between 1,000-90,000 individuals, roughly equating to 670-60,000 mature individuals.

Trend Justification:  The population trend is difficult to determine because of uncertainty over the main threats to the species.

Current Population Trend: Unknown
Additional data:
Number of mature individuals: 670-60000 Continuing decline of mature individuals: Unknown
Extreme fluctuations: No Population severely fragmented: No
Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: No

Habitat and Ecology [top]

Habitat and Ecology: It may breed on offshore islands or mainland cliffs, but is most likely to nest inland in the arid Atacama Desert.

Systems: Terrestrial; Marine
Continuing decline in area, extent and/or quality of habitat: Unknown
Generation Length (years): 16
Movement patterns: Full Migrant
Congregatory: Congregatory (and dispersive)

Threats [top]

Major Threat(s): Until the breeding grounds are found, the extent to which it is threatened by mining-related activity will remain unknown (Brooke 1999).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
None is known.

Conservation Actions Proposed
Search for breeding colonies on offshore islands, coastal cliffs and the arid hinterland of the Antofagasta region in March-July, looking for burrows and signs of nesting, listening for night-time flight calls and following up reports of dead or grounded fledglings inland (Tobias et al. 2006).

Citation: BirdLife International. 2012. Hydrobates hornbyi. The IUCN Red List of Threatened Species 2012: e.T22698567A37856518. . Downloaded on 07 October 2015.
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