Bird Families

Cassin's Auklet (Pichoramophus aluticus) Facts

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Cassin's auklet (Pichoramophus aluticus) is a small, chandelier marine bird that grows widely in the North Pacific. It is known for its casino nest and its presence on the well-known islands outside of British Columbia and California. It is named for John Cassin, a Pennsylvania businessman, and naturalist.

Cassin's auklet is a small (25 cm, 200 g) nondescript ook. Its feathers are usually dark above and pale below, a small white mark on the eye. Its bill is dark with pale spots, and its legs are blue. Cassin's auklet, compared to many others, lacks dramatic breeding plumage, which stays the same throughout most of the year. At sea, it is usually characterized by its flight, which is described as looking like a flying tennis ball.

From the Baja California peninsula to the Aleutian Islands of Alaska to the Central American peninsula, it is home to coastal islands, the main population fortress being Triangle Island, away from Vancouver Island's Cape Scott, where the population is estimated at 55,000. It is not known why, but in winter the northern birds may move further south.

Cassin's auklet is divided into two subspecies:

P. A. Aluticus - (Palas, 1811): the Aleutian Islands and southern Alaska to northern Baja California.
P. A. Australia - (Van Rossem, 1939): Southern Baja California.

Extinct relatives or ancestral species, Pichoramophus tenuis L.H. Miller et Bowman, 8, is known as the Late Pliocene at the San Diego Formation in California.

Behavior

Cassin's auklet builds old nests on small islands and is found year after year in the southernmost colony of its range. It uses easy man-made structures, digging holes in the ground or using natural cracks and crevices for nesting.

The pairs will show strong loyalty to each other and a nest site for many years. To prevent predators such as the western gull or the peregrine falcon, both parents spread a single white egg, exchanged at night (usually after 24 hours), returning from the colony before dawn.

The egg is incubated for 40 days, the baby is fed overnight for 35 days. Both parents, who carry a special thin bag of partially digested food (Euphausids and other small crustaceans), are often referred to in the literature as sublingual. Bag.

The flea escapes to the sea alone. Cassin's auklet is unusual in marine birds, having occasionally placed a second clutch after a successful first clutch, only to do so in the northern hemisphere beach.

Most individuals in one group started breeding at 3 years of age (27%) and within 8 years> 95% of the given cohort had been recruited. The average age of recruitment is 6.6 years. The minimum annual fertility trend is 0.83, apparent local survival is 0.76, adolescent survival (age 0 to 2) is 0.15.

Cassin's auklets feed on the bay along the coast, often in clear aquatic waters, often combined with sediments such as valleys and surfaces beneath the baths. Sea numbers can be severely reduced as the birds move more than a kilometer away from the ship.

Their distribution around Triangle Island has recently been determined by telemetry. It dips with its wings to dive for its expansion, hunting large zooplankton, especially krill. It can sink below 30 meters to the surface, and by some estimates is 80 meters.

Conservation

Cassin's auklet has been listed as a near threat, and some populations (mainly the population of the Farallon Islands) have steadily declined. Threats to the Cassin's auklet include muscle mass (especially Alaska), oil spills and changes in sea surface temperature.

Cassin's auklet is protected under the Migratory Bird Contract Act of 1997. Annual variation in ocean climate affects multiple population parameters, including simultaneous survival, reproductive trends, reproductive success, and recruitment, a situation favorable for rapid population decline due to climate change.

Watch the video: Voices: American Bittern (March 2021).

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