White-chinned petrel (Procellaria aequinoctialis)
|French:||Pétrel à menton blanc|
|Size||Length: 51 – 58 cm (2)|
Wingspan: 134 – 147 cm (2)
|Weight||1 – 1.4 kg (2)|
Classified as Vulnerable (VU) on the IUCN Red List 2006 (1) and listed on Appendix II of the Convention on the Conservation of Migratory Species (CMS) (3).
This large, bulky bird spends nearly all its time at sea, and has many adaptations for this oceanic life style. Its plumage is almost entirely black, apart from the underside edge of the large wings, which are built for continuous flight over great distances, interspersing slow wingbeats with glides (2) (4). Its webbed feet are also black, whilst the bill is a pale-ivory yellow, or whiter in juveniles, with black parts. However, the bill does not have a black tip, which is a useful feature to help distinguish this bird from other black petrels. Despite its name, not all these petrels have a white chin, and even those that do, it is not very noticeable (2) (5). Its Latin name is far more suited as Procella means storm, and aequinoctialis is of the equator, and the white-chinned petrel is a bird of the equatorial storms, however, not more so than many other petrels (4). This petrel is also sometimes called ‘shoemaker’, a name which arose from the noisy succession of clacks and rattles it makes when in its burrow (6). When at its breeding colony the white-chinned petrel can also be heard making staccato, wheezy, moaning calls (5). Although this species was often lumped with the spectacled petrel (Procellaria conspicillata) in the past, they are now considered two separate species (4).
White-chinned petrels can be found widely in all southern oceans, but breed on only a small number of sub-Antarctic islands; South Georgia, Falkland Islands, Prince Edward Islands, Crozet Islands, Kerguelen Islands, Auckland, Campbell and Antipodes Islands, and possibly on Macquarie Island (5).
A pelagic bird, the white-chinned petrel prefers offshore waters over the continental shelf, and is frequently found in convergence zones, where strong ocean currents meet, and in areas of upwelling, where cold, nutrient rich waters from the ocean depths rise to the surface. Their breeding habitat is characterised by vegetated slopes, or flat, waterlogged, peaty ground (2).
The white-chinned petrel is one of the largest burrowing petrels, which build large, cavernous burrows, in which to lay their eggs. The breeding burrows can be up to 2 m long, and are often entered via a small pool, whilst the nest chamber houses a raised, dry platform of earth and vegetation (4) (6). These burrows are built in colonies, and when the breeding season starts in October, only one egg is laid. The egg is incubated intermittently for 57 – 62 days as the parent will often leave the egg for a couple of days to forage (2) (7). The dark brown downy chicks, which are left unguarded in the burrow from a very young age, will fledge after 87 – 106 days (2) (7). White-chinned petrels can live for over 30 years, and during this time they are very faithful to their breeding sites, returning to the same location, and even the same burrow, year after year (7).
When not breeding, they forage out over the ocean, feeding during the night on cephalopods, crustaceans and fish (2). They most frequently feed by sitting on the water and seizing prey with their bill, but can also dive into the ocean, propelling themselves with their powerful wings, reaching depths of up to 10 meters (2) (6). White-chinned petrels are wily eaters; they range more widely than some other seabirds when searching for food, to avoid competition (5), and also can be seen congregating around fishing vessels where they scavenge waste for an easy meal (2).
On land, introduced species pose the greatest threat to the white-chinned petrel. Eggs and chicks are preyed on by black rats (Rattus rattus) and Norway rats (Rattus norvegicus) at several of its main breeding localities, such as Crozet and South Georgia (5) (7). Petrels are particularly vulnerable to the effects of introduced predators, because they always return to the same breeding site, even though there are now great threats, and adults often leave incubating eggs and young chicks unprotected at the burrow (7).
At sea, the primary threat to the white-chinned petrel, like other petrels and albatrosses, is the activities of the fishing industry. Great numbers are unintentionally drowned by longline fishing boats; a fishing method that involves a single line up to 130 km long, with thousands of baited hooks attached to it, being pulled behind a boat. Petrels, scavenging in the ocean, try to eat the bait from the line as it is set behind the boat, but instead swallow the hooks and are dragged under and drowned. The white-chinned petrel constitutes the majority of birds killed by longline fisheries in the Southern Ocean (5). Both predation by introduced rats, and fisheries bycatch, pose an enormous threat to white-chinned petrel populations, particularly because these birds lay only one egg per season, and if that egg is lost, it is not replaced. This low reproductive rate means that they cannot breed fast enough to replace those being killed, and a drastic fall in numbers is sadly inevitable (5).
The white-chinned petrel is listed on Appendix II of the Convention on Migratory Species, and is subsequently part of the Agreement on the Conservation of Albatrosses and Petrels (ACAP). ACAP aims to stop or reverse population declines in 28 species from the southern hemisphere, by coordinating action between range states to mitigate known threats to albatross and petrel populations. An action plan has been drawn up which describes a number of conservation measures to be implemented including research and monitoring, reducing fisheries-related mortality, eradicating non-native species at breeding sites, and reducing habitat loss, disturbances and pollution (8). Population monitoring and ecology research is currently being undertaken at South Georgia, Crozet and Prince Edward Islands (5), and the Falkland Islands has successfully reached a target to reduce seabird deaths to 16 or fewer per year (9).
In addition to this, a number of organisations are working together to encourage and train fisherman to use methods that reduce the threat of longlines to seabirds. These methods include using devices to scare birds away from the longlines, releasing the line from the boat underwater out of reach of the birds, and using weights so the lines sink more quickly (9). Whilst this is aimed primarily at albatrosses, it will also greatly benefit whit-chinned petrels. New Zealand has recently imposed new restrictions on long line fishing within its waters; all vessels must have bird scaring devices and lines must be set at night (9). However, as the white-chinned petrel feeds extensively at night, this measure is not as effective as for albatrosses that feed during the day (4).
For further information on the conservation of the white-chinned petrel see the Agreement on the Conservation of Albatrosses and Petrels:
For further information on the threat of longlining to seabirds and the solutions see Save the Albatross:
For more information on this and other bird species please see:
- BirdLife International:
This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
- Cephalopods: from the Greek for ‘head-foot’, a class of molluscs that occur only in marine habitats. All species have grasping tentacles, and either an internal or external shell. Includes nautiloids, cuttlefish, squids, octopuses, and extinct ammonites and belemnites.
- Crustaceans: a diverse group of arthropods (a phylum of animals with jointed limbs and a hard chitinous exoskeleton) that includes crabs, lobsters, shrimps, slaters, woodlice and barnacles.
- Forage: the act of searching for food.
- Pelagic: inhabiting the open oceans.
IUCN Red List (January, 2007)
- del Hoyo, J., Elliott, A. and Sargatal, J. (1992) Handbook of the Birds of the World. Vol. 1: Ostrich to Ducks. Lynx Edicions, Barcelona.
CMS (January, 2007)
- Brooke, M. (2004) Albatrosses and Petrels across the World. Oxford University Press, Oxford.
Birdlife International (May, 2007)
New Zealand Birds (May, 2007)
- Jouventin, P., Bried, J. and Micol, T. (2003) Insular bird populations can be saved from rats: a long-term experimental study of white-chinned petrels Procellaria aequinoctialis on Ile de la Possession, Crozet archipelago. Polar Biology, 26: 371 - 378.
CMS (May, 2007)
Save the Albatross (May, 2007)