Cape petrel

Cape petrel
D. capense south east of Tasmania
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Procellariiformes
Family:	Procellariidae
Genus:	Daption Stephens, 1826
Species:	D. capense
Binomial name
Daption capense (Linnaeus, 1758)
Subspecies
D. capense capense (Linnaeus, 1758) D. capense australe (Mathews, 1913)

The Cape petrel (Daption capense), also called Cape pigeon or pintado petrel, is a common seabird of the Southern Ocean from the family Procellariidae. It is the only member of the genus Daption, and is allied to the fulmarine petrels, and the giant petrels. It is also sometimes known as the Cape fulmar. They are extremely common seabirds with an estimated population of around 2 million.

Taxonomy

The Cape petrel is the only known member of the genus Daption and is in turn a member of the family Procellariidae and order Procellariiformes. There appears to be a subgroup within the family consisting of the giant petrels, the members of Fulmarus, the Antarctic petrel, and the snow petrel.

All Procellariiformes share certain identifying features. First, they have nasal passages that attach to the upper bill called naricorns. The bills of Procellariiformes are also unique in that they are split into between seven and nine horny plates. They produce a stomach oil made up of wax esters and triglycerides that is stored in the proventriculus. This can be sprayed out of their mouths as a defence against predators and as an energy rich food source for chicks and for the adults during their long flights. Finally, they also have a salt gland that is situated above the nasal passage and helps desalinate their bodies, due to the high amount of ocean water that they imbibe. It excretes a high saline solution from their nose.

Subspecies

The Cape petrel has two subspecies

• D. capense capense breeds on circumpolar subantarctic islands.
• D. capense australe breeds on New Zealands subantarctic islands.

Description

The Cape petrel is a unique looking petrel. It has a black head and neck, and a white belly, breast, and its underwing is white with a black border. Its back, and upperwings are black and white speckled, as is its tail which also has a band of black. When fully grown, their wings span 86 cm (34 in) and they are 39 cm (15 in) long.

Etymology

Daption is derived from Ancient Greek for "little devourer", and the Cape name is because of where the type specimen was collected. Finally, pintado is Spanish for "painted" for its plumage. One of their other names, Cape pigeon, is from their habit of pecking at the water for food. The word petrel is derived from St. Peter and the story of his walking on water. This is in reference to the petrel's habit of appearing to run on the water to take off.

Diet

The Cape petrels' diet is 80% crustaceans, as well as fish and squid. Krill is their favourite crustacean, which they obtain by surface seizing as well as diving under water and filtering them out. They are also known for following ships and eating edible waste and carcasses thrown overboard. They are aggressive while feeding and will spit their stomach oil at competitors, even their own species.

Breeding

A breeding Cape petrel at King George Island

Daption capense, egg – MHNT

They are colonial birds, and nest on cliffs or level ground within a kilometre of the ocean. They tend to have smaller colonies than other petrels. Their nests are formed with pebbles and are placed under overhanging rock for protection, or in a crevice. In November they lay a single egg, which is incubated for 45 days by both sexes. Like most other fulmars, they will defend their nest by spitting stomach oil. Skuas in particular will prey on Cape petrel eggs and chicks. Upon hatching, the chick is brooded for ten days until it can thermoregulate, after which both parents assist in the feeding. The chicks fledge after 45 more days, around March.

Range and habitat

During breeding season, Cape petrels feed around Antarctica's shelf and during the winter they range further north, as far as Angola and the Galapagos Islands. They breed on many islands of Antarctica and the subantarctic islands, some going as far as the Auckland Islands, the Chatham Islands, Campbell Island. Their main breeding grounds were on the Antarctic Peninsula, South Georgia, the Balleny Islands, the Kerguelen Islands, as well as islands in the Scotia Sea.

Conservation

The Cape petrel has an occurrence range of 146,000,000 km² (56,370,915 sq mi) and a 2009 estimate places their population of adult birds at 2 million. Consequently, the IUCN rates them as least concern.