White-chinned petrel | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Procellariiformes |
Family: | Procellariidae |
Genus: | Procellaria |
Species: | P. aequinoctialis |
Binomial name | |
Procellaria aequinoctialis Linnaeus, 1758 |
The white-chinned petrel or Cape hen,Procellaria aequinoctialis, is a large shearwater in the family Procellariidae. It ranges around the Southern Ocean as far north as southern Australia, Peru and Namibia, and breeds colonially on scattered islands.
The white-chinned petrel is a member of the Procellaria genus, and in turn is a member of the Procellariidae family, and the Procellariiformes order. As a member of the Procellariiformes, they share certain identifying features. First, they have nasal passages that attach to the upper bill called naricorns. Although the nostrils on the petrel are on top of the upper bill. 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.
Procellaria comes from two Latin words, procella "storm" and arius "pertaining to", with reference to the birds' association with stormy weather. The word petrel is derived from Saint Peter and the story of his walking on water, referring to their appearing to run on the water's surface when taking to the air.