Hydrobates microsoma 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Procellariiformes Hydrobatidae

Scientific Name: Hydrobates microsoma
Species Authority: (Coues, 1864)
Common Name(s):
English Least Storm-petrel, Least Storm Petrel, Least Storm-Petrel
Halocyptena microsoma Coues, 1864
Oceanodroma microsoma AOU checklist (1998 + supplements)
Oceanodroma microsoma Sibley and Monroe (1990, 1993)
Oceanodroma microsoma SACC (2005)
Oceanodroma microsoma BirdLife International (2004)
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 microsoma (del Hoyo and Collar 2014) was previously placed in the genera Oceanodroma and Halocyptena.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Facilitator/Compiler(s): Butchart, S., Calvert, R. & Ekstrom, J.
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Previously published Red List assessments:
2009 Least Concern (LC)
2008 Least Concern (LC)
2004 Least Concern (LC)
2000 Lower Risk/least concern (LR/lc)
1994 Lower Risk/least concern (LR/lc)
1988 Lower Risk/least concern (LR/lc)

Geographic Range [top]

Range Description: This species breeds on islands in the Gulf of California and on the western coast of Baja California (Mexico). Its range stretches from California (USA) to as far south as Colombia and Ecuador1.

Countries occurrence:
Colombia; Costa Rica; Mexico; Panama; United States
Present - origin uncertain:
Ecuador; El Salvador; Guatemala; Nicaragua
Continuing decline in area of occupancy (AOO): Unknown
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 111000
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 hundreds of thousands of individuals, possibly millions.

Trend Justification:  The population is suspected to be in decline owing to predation by invasive species.
Current Population Trend: Decreasing
Additional data:
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: This species is marine and often pelagic, mainly occurring over warm waters away from land. Its diet is comprised mostly of small planktonic crustaceans, particularly the larvae of the spiny lobster. It feeds on the wing, by pattering, and by surface-seizing whilst on the water. Breeding starts in June or July, forming colonies on small islands or rocky stacks and nesting in rock crevices (del Hoyo et al. 1992)
Systems: Terrestrial; Marine
Continuing decline in area, extent and/or quality of habitat: Unknown
Generation Length (years): 15.2
Movement patterns: Full Migrant
Congregatory: Congregatory (and dispersive)

Citation: BirdLife International. 2012. Hydrobates microsoma. The IUCN Red List of Threatened Species 2012: e.T22698485A40200955. . Downloaded on 30 November 2015.
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