White-chinned Petrel

The White-chinned Petrel, known to some as the Cape Hen or Shoemaker, is a majestic member of the Procellariidae family. This large shearwater is the most substantial species within its genus Procellaria, and indeed, outside of the giant petrels, it is the largest in its family. The bird's plumage is predominantly sooty-black, with variable amounts of white on the throat and chin, the latter being more pronounced in individuals from the Indian Ocean than the Atlantic. The White-chinned Petrel's wingspan stretches impressively between 134 to 147 centimeters, and it exhibits a body length of 51 to 58 centimeters. Males are generally heavier, averaging around 1,390 grams, while females tip the scales at approximately 1,280 grams. When observed in flight, this petrel is known to alternate between slow, deliberate wingbeats and graceful glides.

Identification Tips

Upon sighting, look for the White-chinned Petrel's distinctive white throat and chin patch, which stands out against its dark plumage. The bird's bill is either horn-colored or yellow with black between the nostrils, and its legs and feet are black. In flight, the petrel's underwing may reveal a silvery sheen, particularly noticeable on the primaries.

Habitat

During the breeding season, the White-chinned Petrel is found on scattered islands throughout the Southern Ocean. It favors islands with suitable nesting sites, where it can establish colonies.

Distribution

This species has a circumpolar distribution, ranging as far north as southern Australia, Peru, and Namibia. It breeds on various islands, including South Georgia, the Kerguelen Islands, and the Falkland Islands, among others. Outside the breeding season, these birds can be found from the Antarctic pack ice to subtropical waters.

Behaviour

The White-chinned Petrel is a colonial breeder, with both sexes contributing to nest building and incubation. They are also known to be cooperative in feeding and protecting their young. While generally silent, they may emit a rattling or groaning sound within their colonies.

Song & Calls

Typically quiet when at sea, the White-chinned Petrel is more vocal on land, particularly within its breeding colonies where it may produce rattling or groaning noises.

Breeding

Both male and female White-chinned Petrels are involved in constructing the nest and incubating the egg. They share responsibilities in feeding and safeguarding their offspring until they are ready to fledge.

Diet and Feeding

The diet of the White-chinned Petrel primarily consists of krill, supplemented by fish. They employ surface seizing and shallow diving techniques to forage and are known to follow ships, scavenging on discarded bycatch.

Conservation status

The White-chinned Petrel is currently classified as Vulnerable by the IUCN. Threats include mortality from longline fisheries, where they are often caught as bycatch, and predation by invasive species on breeding islands. Conservation efforts include protected breeding sites and ongoing population monitoring, with proposals to mitigate bycatch and control invasive species.