Ainley's Storm-petrel vs Fork-tailed Storm-petrel

Hydrobates cheimomnestes compared with Hydrobates furcatus

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Side-by-Side Comparison

Attribute Ainley's Storm-petrel Fork-tailed Storm-petrel
Scientific Name Hydrobates cheimomnestes Hydrobates furcatus
Order Procellariiformes Procellariiformes
Family Hydrobatidae Hydrobatidae
Conservation Status Vulnerable Least Concern
Length
Wingspan 30.1 cm (11.9 in) 31.1 cm (12.2 in)
Weight 41.15 g (1.45 oz) 63.5 g (2.24 oz)
Diet -- --
Clutch Size 1 1
Population Trend
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Habitat Comparison

Shared Habitats

None

Ainley's Storm-petrel only

None

Fork-tailed Storm-petrel only

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Conservation Status

Vulnerable

Ainley's Storm-petrel

Least Concern

Fork-tailed Storm-petrel

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About These Birds

Ainley's Storm-petrel

Ainley's Storm-petrel, 19–21 cm, is a recently described species breeding on the Channel Islands off California, present in winter — unusual among storm-petrels which typically breed in summer. Dark overall, white rump with central grey stripe. Vulnerable; small population and restricted range.

Fork-tailed Storm-petrel

Fork-tailed Storm-petrel, 20–23 cm, is a distinctive pale grey storm-petrel of the North Pacific, breeding on islands from California to Japan. Pale blue-grey body, dark wing tips, forked tail. Unlike most storm-petrels, feeds largely on fish and marine debris rather than zooplankton alone. Winters offshore.

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