Fork-tailed Storm-petrel (Oceanodroma furcata)

Fork-tailed Storm-petrel

[order] PROCELLARIIFORMES | [family] Hydrobatidae | [latin] Oceanodroma furcata | [authority] Gmelin, 1789 | [UK] Fork-tailed Storm-petrel | [FR] Oceanite a queue fourchue | [DE] Gabelschwanz-Wellenlaufer | [ES] Paino Rabihorcado | [NL] Parelgrijs Stormvogeltje

Subspecies

Monotypic species

Genus

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.

Physical charateristics

Gray; paler below, unlike all our other storm-petrels, which are blackish.

Listen to the sound of Fork-tailed Storm-petrel

[audio:http://www.planetofbirds.com/MASTER/PROCELLARIIFORMES/Hydrobatidae/sounds/Fork-tailed Storm-petrel.mp3]

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
broods: 1   eggs min.: 1  
      eggs max.: 1  

Range

Pacific Ocean : North. This species is found throughout the North Pacific, with sites ranging from the Californian coast (USA) in the east, the Alaskan coast in the north and the Kuril Islands (Russia) in the west. Outside the breeding season it disperses over adjacent waters

Habitat

Open ocean. Favors cold waters, foraging over continental shelf and farther out to sea, sometimes fairly close to land. Extends nort
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.

Reproduction

Nests on islands, commonly in large colonies. Active around nesting sites only at night, probably to evade predators.
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.

Feeding habits

Includes fish, crustaceans.
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.

Conservation

This species has an extremely 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). The population trend appears to be increasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely 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.
Fork-tailed Storm-petrel status Least Concern

Migration

North Pacific. Resident offshore within dash line. Migration: Not strongly migratory, with most remaining in far northern waters all year. In some winters, fair numbers move south to central California, rarely farther.

Distribution map

Fork-tailed Storm-petrel distribution range map

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