Family Northern Storm-petrels (Hydrobatidae)

Least Concern

Least Storm-petrel (Hydrobates microsoma)


French: Océanite minute German: Zwergsturmschwalbe Spanish: Paíño menudo

Halocyptena microsoma


, 1864,

San José del Caba, Baja California, Mexico


Recent genetic data#R indicate that present species is sister to H. tethys, and that the two are sister to H. melania; proposal that the three perhaps should be grouped in a separate genus Halocyptena is not supported by other authors#R. Monotypic.


Subtropical E Pacific S to Ecuador, breeding on Islands in Gulf of California and off W coast of Baja California (NW Mexico).

Descriptive notes

13–15 cm; 14–22 g; wingspan 32–36 cm. Smallest seabird with nearly uniform dark plumage and wedge-shaped tail (although latter can appear rounded in flight... read more


Vocalizations weaker and less scratchy than those of H. melania, the Burrow Call being... read more


Marine and often pelagic, mainly occurring over warm waters away from land. Breeds on small islands... read more

Food and feeding

Mostly small planktonic crustaceans, particularly larvae of spiny lobster Panulirus. Feeds on wing, by pattering, and also by... read more


Starts Jun/Jul in N part of breeding, with newly hatched young recorded 12 Aug to 8 Sept. Speculated to arrive at San Benito Is later than... read more


Most move away from breeding islands between Oct and Mar. Disperses S to winter off W coast of... read more

Status and conservation

Not globally threatened (Least Concern). Most abundant seabird in Gulf of California, with 100,000s or possibly 1,000,000s, with potentially largest populations on islands of... read more

Recommended citation

Carboneras, C., Jutglar, F. & Kirwan, G.M. (2019). Least Storm-petrel (Hydrobates microsoma). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from on 25 March 2019).