Fr: Pétrel antarctique
Ang: Antarctic Petrel
All: Antarktiksturmvogel
Esp: Petrel Antártico
Ita: Procellaria antartica
Nd: Antarctische Stormvogel
Sd: Antarktispetrell
Photographer:
Otto Plantema
Trips around the world
Text by Nicole Bouglouan
Sources:
HANDBOOK OF THE BIRDS OF THE WORLD vol 1 by Josep del Hoyo-Andrew Elliot-Jordi Sargatal - Lynx Edicions - ISBN: 8487334105
A Complete Guide to Antarctic Wildlife by Hadoram Shirihai and Illustrated by Brett Jarrett - Edited by Guy M. Kirwan - ALUL.A Press Oy, Finland - ISBN 9519894705
BirdLife International (BirdLife International)
Department of Sustainability, Environment, Water, Population and Communities
New Zealand birds and birding (Narena Olliver)
Wikipedia, the free encyclopaedia
Antarctic Petrel
Thalassoica antarctica
Procellariiformes Order – Procellariidae Family
INTRODUCTION:
The Antarctic Petrel is included in the “fulmar-petrel” group in the family Procellariidae. This species is distinct enough to be placed in the separate, monotypic genus Thalassoica.
It is an agile flier and is very active on the water. It appears less clumsy on land than most other petrels. It rarely wanders far from pack ice and icebergs. It breeds in dense colonies and its population is large and currently stable.
DESCRIPTION OF THE BIRD:
Biometrics:
Length: 40-46 cm
Wingspan: 100-110 cm
Weight: 510-765 g
The adult is a medium-sized petrel with dark chocolate-brown and white plumage.
It has dark brown hood and upperparts to rump. Uppertail-coverts and tail are white, except the dark brown terminal band.
On the upperwing, the anterior half is dark brown and includes the primary-coverts and the outer primaries. The rear half is white and forms a broad white wingbar on secondaries to inner primaries. The dark brown feather tips form a narrow trailing edge broken on inner primaries.
The underparts are white except the dark terminal tail band, the broad dark brown leading edge and the narrow trailing edge.
The transition between the white underparts and the dark hood is not very sharp. The central area is whitish up to chin, whereas the dark area extends from breast sides to axillaries.
The head is entirely dark brown. The bill is blackish-brown, slightly tinged dull olive on sides. The eyes are blackish. Legs and webbed feet are greyish with some pinkish tinge especially on webs.
In worn plumage, the upperparts are paler brown with some faint scaling. There is sometimes an indistinct pale collar.
Male and female are similar, but the female is slightly smaller overall.
The juvenile resembles adult but with black bill. Feathers of mantle and inner upperwing-coverts are narrowly edged whitish.
RANGE:
The Antarctic Petrel is found in Southern Ocean. It breeds on coastal Antarctica and up to 250 kilometres inland and on surrounding islands.
The species ranges widely N to S South America, South Africa, Tasmania and New Zealand.
HABITAT:
The Antarctic Petrel is often seen around the Antarctic continent, in the vicinity of pack-ice and icebergs. It breeds on cliff faces and ice-free rocky peaks in the Antarctic mainland, and on some islands within the Antarctic ice fields.
There are some breeding sites on seacliffs, but others can be up to 250 kilometres inland, and up to 1600 metres of elevation.
CALLS AND SONGS: SOUNDS BY XENO-CANTO
The Antarctic Petrel is usually silent at sea. But during courtship displays at nest-site, it produces churring, clucking and cackling calls.
BEHAVIOUR IN THE WILD:
The Antarctic Petrel feeds primarily on cephalopods (Gonatus antarctica), small fish, krill (Euphausia antarctica), crustaceans and medusae, all caught by surface-seizing and plunge-diving (up to 1,50 metres deep). It also performs contact-dipping.
They form large flocks around the wailing ships, and forage in association with cetaceans that drive the preys to the surface.
The Antarctic Petrel is highly gregarious and forages in large flocks, often with other species such as Cape Petrel and Southern Fulmar.
It often breeds in mixed colonies with other Procellariidae such as Southern Fulmar, Cape Petrel and Snow Petrel.
During the courtship displays, the birds give a hen-like clucking while throwing their heads back until the crown almost touches the back.
They are monogamous with long-term pair-bonds, although some extra-pair copulations are known.
The Antarctic Petrel forms large colonies ranging from 100 pairs to over 1,000,000 birds. The nests can be placed less than one metre apart. They nest on cliff ledges or among rocks, on snow-free slopes.
This species disperses within areas of floating ice outside breeding season. Some birds may move N in winter, and reach the Antarctic Convergence, between the 48th and 61st parallels of South latitude.
The species is regularly seen around South Georgia in summer, between June and August. It is vagrant to the Falklands, South Africa, New Zealand and Tasmania.
The Antarctic Petrel typically makes stiff-winged glides on long narrow wings. It performs more wing flapping and shorter glides than fulmars.
REPRODUCTION OF THIS SPECIES:
The breeding season starts in November, following a pre-laying exodus of 3-4 weeks in October/November.
They are monogamous, but occasionally, a breeding female may be joined by an unsuccessful female and they rear the chick together. In addition, a female may sometimes mate with the neighbour male, because a high proportion of females can be frequent in some colonies.
They breed in colonies established on cliff ledges or among rocks, in hollows. The nest is a shallow depression sparsely lined with small pebbles, bones or feathers.
The female lays a single white egg. Both adults incubate during 40-46 days in 5-6 shifts, but the male takes longer shifts than female.
At hatching, the chick is covered with pale grey down, but head and neck are slightly whiter. It is brooded during 9-21 days and fed every day by both parents. It fledges 42-47 days after hatching.
The South Polar Skua is a predator of adults, chicks and eggs. The breeding success is influenced by climatic conditions involving variations in the environment and food resources.
PROTECTION / THREATS / STATUS:
The Antarctic Petrel has large range and its populations are stable. The global population may number several millions birds, ranging between 10,000,000 and 20,000,000 individuals in 2004.
But currently, the Antarctic Petrel is evaluated as Least Concern.