[order] PROCELLARIIFORMES | [family] Procellariidae | [latin] Puffinus pacificus | [authority] Gmelin, 1789 | [UK] Wedge-tailed Shearwater | [FR] Puffin fouquet | [DE] Keilschwanz-Sturmtaucher | [ES] Pardela del Pacifico | [NL] Wigstaartpijlstormvogel
Subspecies
| Genus | Species | subspecies | Region | Range |
| Puffinus | pacificus | PO, IO | widespread |
Genus
Until recently the shearwaters were devided in two genera Calonectris and Puffinus, but based on dna-analysis Penhallurick and Wink (2004) have proposed a splitting of the shearwaters into three genera: Calonectris for the large shearwaters of the Northern Atlantic, the Mediterranean and the waters around Japan, Ardenna for a group of large Southern Hemisphere breeders and Puffinus for the smaller shearwaters such as the Manx’ group, Audubon’s and Little Shearwaters. This new taxonomy is now widely accepted, but not by all and is stil subject of discussion.
Physical charateristics
The Wedge-tailed Shearwater is a dusky brown bird with white breast feathers, long and thin wings, a hooked bill, and a wedge-shaped tail.
Listen to the sound of Wedge-tailed Shearwater
[audio:http://www.planetofbirds.com/MASTER/PROCELLARIIFORMES/Procellariidae/sounds/Wedge-tailed Shearwater.mp3]
Copyright remark: Most sounds derived from xeno-canto
| wingspan min.: | 97 | cm | wingspan max.: | 105 | cm |
| size min.: | 41 | cm | size max.: | 46 | cm |
| incubation min.: | 50 | days | incubation max.: | 54 | days |
| fledging min.: | 95 | days | fledging max.: | 105 | days |
| broods: | 1 | eggs min.: | 1 | ||
| eggs max.: | 1 |
Range
Pacific Ocean, Indian Ocean : widespread. The Wedge-tailed Shearwater ranges across from throughout the tropical Pacific and Indian Ocean roughly between latitudes 35 degrees N and 35 degrees S, breeding on a large number of oceanic islands and on the east and west coasts of Australia
Habitat
This marine species can nearly always be found over pelagic waters except when at colonies. Its breeding season is very variable nesting in burrows in colonies on offshore islands or atolls
Reproduction
Monogamous. Strictly nocturnal over breeding colony. Their courtship ritual begins shortly after arrival in late March. A pair will sit head to head, often near their burrow entrance, vocalizing two-part wailing duets. Returning to the same nest site each year, Wedge-tails nest in shallow burrows, one to two meters in length. A single, large, white egg is laid in a nesting chamber at the end of burrow. Egg laying occurs throughout the month of June. No relaying will occur if an egg is lost. Incubation period averages 53 days with both parents alternating shifts on the egg, with each shift lasting as long as 12 days. Chicks hatch during late-July through late August. Parents feed regurgitated squid and stomach oil to chicks. Feeding takes place every 24 hours and is brief visits during the first week. Fledging occurs in approximately 100-115 days. Parent desertion of the chick typically occurs shortly before fledging.
Feeding habits
It feeds mostly on fish, with some cephaolopods, crustaceans and insects. It catches prey mainly on the wing by dipping but also by surface-seizing or pursuit-plunging. It will congregate with other seabirds and dolphins when around schooling fish, and will often attend trawlers and smaller fishing boats.
Video Wedge-tailed Shearwater
httpv://www.youtube.com/watch?v=21CuzGVT_Vc
copyright: Tom Tarrant
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). 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 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.
Migration
Some populations apparently largely sedentary, especially in tropics; others at extreme N and S of range tend to migrate to warm waters of tropical and subtropical Pacific and Indian Oceans, many crossing equator; regular N to Gulf of Aden and S off S Africa.
Distribution map
