Storm-petrels are rather small and often dark colored tubenoses with a world wide distribution. All have fine black bills with very pronounced tubes. Storm Petrels are separated in two groups: the long legged, Southern Hemisphere birds subfamily Oceanitinae and the shorter legged species of more northern seas the subfamily Hydrobatinae. The first groups shows more morphological differences than the second. The genera are characterised on colour patterns, the condition of the nasal tubes, tail shape, structure of claws and proportions of the leg bones. The genus Oceanodroma consists of medium-sized petrels; plumage dark or greyish, often with pale rumps; tail more or less forked; tarsus short , middle toe with claw and scutellate; claws narrow.
Listen to the sound of Fork-tailed Storm-petrel
Copyright remark: Most sounds derived from xeno-canto
|wingspan min.:||45||cm||wingspan max.:||48||cm|
|size min.:||20||cm||size max.:||23||cm|
|incubation min.:||37||days||incubation max.:||68||days|
|fledging min.:||49||days||fledging max.:||60||days|
h into Bering Sea, and may even occur around edges of floating ice. Nests on islands, mostly hilly islands with good cover of grass or shrubs.
Nest: Excavates burrow in soil or uses natural rock crevices, openings in rock piles, or old burrows of other species (such as puffins). Sometimes two or more pairs have nests in side tun
nels branching off from single entrance. Nest chamber usually with little or no lining added, sometimes small amount of grass.
Clutch 1. Dull white, with fine dark dots around larger end. Incubation by both sexes. Incubation period averages about 50 days, but ranges from 37-
68 days, with wide variation partly because egg sometimes neglected for days at a time.
Young: Both parents feed young. At first, young is fed orange oily substance regurgitated by adults, later semi-digested fish. Young fledges about 60 days after hatching, goes out to sea.
Feeds mostly on small fish, crustaceans, and floating natural oils. Skims oily fat (from dead or wounded animals) from surface of water. Also may feed on carrion or floating refuse.
Behavior: Takes food from surface of water. Forages mostly by hovering and picking at surface with bill, also by dropping into water and then resuming flight, sometimes by picking at items while swimming.