The North Pacific albatross are large seabirds from the genus Phoebastria in the albatross family.
They are the most tropical of the albatrosses, with two species ( the Laysan Albatross and Black-footed Albatross) nesting in North Western Hawaiian island chain, one on sub-tropical islands south of Japan (the Short-tailed Albatross), and one nesting on the equator (the Waved Albatross).
Description
The North Pacific Albatross ranges in size from 190–240 cm (75–94 in) and they all have short black tails.
Species
Genus Phoebastria – North Pacific albatrosses
- Phoebastria immutabilis, Laysan Albatross
- Phoebastria nigripes, Black-footed Albatross
- Phoebastria irrorata, Waved Albatross
- Phoebastria albatrus, Short-tailed Albatross
This genus and Diomedea had already diverged in the Middle Miocene (12-15 mya). Several fossil forms are known, which incidentally prove that Phoebastria was formerly distributed in the North Atlantic also. The current distribution is thus a relict. The oldest known species, P. californica, was at least the size of the Short-tailed Albatross and may have been an ancestor of this bird.
Fossil species
- Phoebastria californica (Temblor Middle Miocene of Sharktooth Hill, USA)
- Phoebastria anglica (Middle Pliocene – Early Pleistocene of NC Atlantic coasts)
- Phoebastria cf. albatrus (San Diego Late Pliocene of San Diego County, USA) – formerly Diomedea howardae
- Phoebastria rexsularum
- Phoebastria cf. immutabilis (San Pedro Pleistocene of San Pedro, USA)
- Phoebastria cf. nigripes (San Pedro Pleistocene of San Pedro, USA)
Behavior
The feeding habits of these albatrosses are similar to other albatrosses in that they eat fish, squid, crustacea, and carrion (carcass of a dead animal).
When roosting, they choose isolated sites and lay one egg, with both parents incubating and raising the chick. They are monogamous species, and they don’t start breeding until they are 5–15 years old.
Taxonomy
Their taxonomy is very confusing, as with all albatrosses. It is widely accepted nowadays, based on molecular evidence and the fossil record, that they are a distinct genus from Diomedea in which formerly most “white” albatrosses were placed but which is now restricted to the “Great” albatrosses.
They share certain identifying features. First, they have nasal passages that attach to the upper bill called naricorns. Although the nostrils on the Albatross are on the sides of the bill. The bills of Procellariiformes are also unique in that they are split into between 7 and 9 horny plates. Finally, they produce a stomach oil made up of wax esters and triglycerides that are stored in the proventriculus (stomach). This is used against predators as well as an energy rich food source for chicks and for the adults during their long flights.
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.
