The Cassin’s Auklet is a small, chunky seabird that ranges widely in the North Pacific. It nests in small burrows and because of its presence on well studied islands in British Columbia and off California it is one of the better known auks. It is named for John Cassin, a Pennsylvania businessman and naturalist. Download high resolution version (2272x1704, 827 KB) Photographer Duncan Wright (User:Sabines Sunbird Taken in 2003 on the Farallon Islands. ... Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla Porifera (sponges) Ctenophora (comb jellies) Cnidaria Placozoa Bilateria  Acoelomorpha  Orthonectida  Rhombozoa  Myxozoa  Superphylum Deuterostomia     Chordata (vertebrates, etc. ... Typical Classes Subphylum Urochordata - Tunicates Ascidiacea Thaliacea Larvacea Subphylum Cephalochordata - Lancelets Subphylum Myxini - Hagfishes Subphylum Vertebrata - Vertebrates Petromyzontida - Lampreys Placodermi (extinct) Chondrichthyes - Cartilaginous fishes Acanthodii (extinct) Actinopterygii - Ray-finned fishes Actinistia - Coelacanths Dipnoi - Lungfishes Amphibia - Amphibians Reptilia - Reptiles Aves - Birds Mammalia - Mammals Chordates (phylum Chordata) include the vertebrates, together with... Orders Many - see section below. ... Families Thinocoridae Pedionomidae Scolopacidae Rostratulidae Jacanidae Chionididae Burhinidae Haematopodidae Recurvirostridae Ibidorhynchidae Charadriidae Pluvianellidae Dromadidae Glareolidae Stercorariidae Rhynchopidae Laridae Sternidae Alcidae Charadriiformes is a diverse order of small to medium-large birds. ... Genera Alle Uria Alca Pinguinus Cepphus Brachyramphus Synthliboramphus Ptychoramphus Cyclorrhynchus Aethia Cerorhinca Fratercula Auks are birds of the family Alcidae in the order Charadriiformes. ... In biology, binomial nomenclature is a standard convention used for naming species. ... Peter Simon Pallas (September 22, 1741 - September 8, 1811) was a German-born Russian zoologist. ... 1811 was a common year starting on Tuesday (see link for calendar). ... Seabirds are birds that spend much of their lives, outside the breeding season at least, at sea. ... For other meanings of pacific, see pacific (disambiguation). ... Motto: Splendor Sine Occasu (Splendour without diminishment) Other Canadian provinces and territories Capital Victoria Largest city Vancouver Lieutenant Governor Iona Campagnolo Premier Gordon Campbell (BC Liberal) Area 944,735 km² (5th)  - Land 925,186 km²  - Water 19,549 km² (2. ... State nickname: The Golden State Other U.S. States Capital Sacramento Largest city Los Angeles Governor Arnold Schwarzenegger Official languages English Area 410,000 km² (3rd)  - Land 404,298 km²  - Water 20,047 km² (4. ... Genera Alle Uria Alca Pinguinus Cepphus Brachyramphus Synthliboramphus Ptychoramphus Cyclorrhynchus Aethia Cerorhinca Fratercula Auks are birds of the family Alcidae in the order Charadriiformes. ... John Cassin (September 6, 1813 - January 10, 1869) was an American ornithologist. ... State nickname: The QUENESE PERSON STATE Other U.S. States Capital Harrisburg Largest city Philadelphia Governor Ed Rendell Official languages None Area 119,283 km² (33rd)  - Land 116,074 km²  - Water 3,208 km² (2. ...

Description and range

The Cassin's Auklet is a small (25 cm, 200 g) nondescript auk. Its plumage is generally dark above and pale below, with a small white mark above the eye. Its bill is overall dark with a pale spot, and its feet are blue. Unlike many other auks the Cassin's Auklet lacks dramatic breeding plumage, remaining the same over most of the year. At sea it is usually identified by its flight, which is described as looking like a flying tennis ball. Closeup on a single white feather A feather is one of the epidermal growths that forms the distinctive outer covering, or plumage, on a bird. ... A breed is a domesticated subspecies or infrasubspecies of an animal. ... Tennis balls This article is about the sport, tennis. ...

The Cassin's Auklet ranges from midway up the Baja California peninsula to Alaska's Aleutian Islands, off North America. It nests on offshore islands, with the main population stronghold being Triangle Island off Vancouver Island's Cape Scott, where the population is estimated to be around 550,000 pairs. It is not known to be migratory, however northern birds may move farther south during the winter. Baja California (highlighted) Alternative use: Baja California (state) Baja California or Lower California is a peninsula in the west of Mexico. ... State nickname: The Last Frontier, The Land of the Midnight Sun Other U.S. States Capital Juneau Largest city Anchorage Governor Frank Murkowski Official languages English Area 1,717,854 km² (1st)  - Land 1,481,347 km²  - Water 236,507 km² (13. ... Looking down the Aleutians from an airplane. ... World map showing location of North America A satellite composite image of North America North America is the third largest continent in area and fourth in population after Asia and Africa in area and population and Europe in population. ... Vancouver Island is a large island in British Columbia, Canada, off the Pacific coast. ... Cape Scott (71º07´S 168º05´E) is a cape at the western side of the terminus of Dennistoun Glacier on the northern coast of Victoria Land in Antarctica. ...

Behaviour

The Cassin's Auklet nests in burrows on small islands, and in the southern area of its range may be found in the breeding colony year round. It either digs holes in the soil or uses natural cracks and crevices to nest in, also readily using man-made structures. Pairs will show a strong loyalty towards each other and to a nesting site for many years. Both the parents incubate the single white egg, returning to swap shifts at night to avoid being taken by predators such as the Western Gull or Peregrine Falcon. The egg is incubated for 40 days, the small chick is then fed nightly for 35 days by both parents, who bring regurgitated food in a special gular pouch. The chick fledges alone and makes its way to the sea. The Cassin's Auklet is unusual amongst seabirds in occasionally laying a second clutch after a successful first clutch (it is the only northern hemisphere seabird to do so). The word incubate in the context of birds refers to the development of the chick (embryo) within the egg and the constant temperature required for the development of it over a specific period. ... Binomial name Larus occidentalis (Audubon, 1839) The Western Gull, Larus occidentalis, is a large white-headed gull that lives on the western coast of North America. ... Binomial name Falco peregrinus Tunstall, 1771 The Peregrine Falcon (Falco peregrinus) is a medium-sized falcon about the size of a large crow: 38-53 cm (15 to 21 inches) long. ... Fledge is the stage in a young birds life when the feathers and wing muscles are sufficiently developed for flight. ...

At sea Cassin's Auklets feeds offshore, in clear often pelagic water, often associating with bathymetric landmarks such as underwater canyons and upwellings. It feeds by diving underwater beating its wings for propulsion, hunting down large zooplankton, especially krill. It can dive to 30 m below the surface, and by some estimates 80 m. The pelagic zone is the part of the open sea or ocean comprising the water column, i. ... Bathymetry is the underwater equivalent to topography. ... Upwelling is an oceanographic phenomenon that occurs when strong, usually seasonal, winds push water away from the coast, bringing cold, nutrient-rich deep waters up to the surface. ... Photomontage of plankton organisms Plankton is the aggregate community of weakly swimming but mostly drifting small organisms that inhabit the water column of the ocean, seas, and bodies of freshwater. ... Families Euphausiidae Bentheuphausiidae Krill are shrimp-like marine invertebrate animals and are important organisms of the zooplankton, particularly as food for baleen whales. ...

Conservation

The Cassin's Auklet is listed as Least Concern; although some populations (principally the Farallon Islands population) have suffered steep declines, overall the species is still numerous. Threats to the auklet include introduced carnivores (particularly in Alaska), oil spills and changes in sea surface temperature (caused by El Niño events). The Farallon Islands are a group of islands and rocks found in the Gulf of the Farallons, off the coast of mainland San Francisco, California. ... Sweet clover (Melilotus sp. ... Volunteers cleaning up the aftermath of the Prestige oil spill An oil spill is the release of oil (generally, petroleum) into the natural environment, usually the ocean. ... El Niño is also the nickname of Sergio García. ...

References

Manuwal, D. A. and A. C. Thoresen. 1993. Cassin’s Auklet (Ptychoramphus aleuticus). In The Birds of North America, No. 50 (A. Poole and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists’ Union.