Bird Families

Crested Auklet (Aethia cristatella) Facts

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There are many beautiful birds in the world. Crested auklet (Aethia cristatella) is a beautiful small sea bird belongs to the Alcidae family, extending into the North Pacific and the Bering Sea. The species die in deep water, eating krill and a variety of marine animals. It is home to dense colonies of 10 million people in the Bering Sea and the Sea of ​​Okhotsk. It is often bred in a mixed breed colony, with a very short ovule, a small congener.

The breed is known for its sexual ornaments, which are found in both men and women. These include pigmented plumage with a forehead crest, citrus fruit with a striking aroma, and an intense horn call, all of which seem to have evolved through sexual selection.

The total population is about a million, almost half of North America. This is generally regarded as worrisome, though Alaskan populations face additional threats as predicted and by oil spills.

Description

The Crested auklet (Aethia cristatella) is 18-25 cm (7.1-10.6 in) in length, can match wings of 34-50 cm (13-20 in) and weighs 195-330 g (6.9-11.6 oz). From their eyes to the ears. There are red-orange and yellow-tipped bills, yellow iris white iris and white auricular plum.

Their body, wings, and tail are predominantly dark gray and the legs and feet are gray and the nails are black. There are very similarities between males and females, although there are some smaller and less curved bills between wives, and also some smaller crests.

The crested auklet (Aethia cristatella) is known for their forehead crests, made by black forward-carving feathers. These forehead crests are highly variable and may have two to twenty narrow frontal curved feathers.

The Crested auklet contains 12 crest feathers, with a variable length between 8.1 and 58.5 millimeters. The Auklets have a bright orange bill with airy plumes and twisted accessory plates. As with forehead crests, these features vary greatly among the owlet population.

The crested auklet (Aethia cristatella) is recognized primarily by the two characteristics of the breeding season. The first is its crest, a group of bridle feathers over the top of its head over the eyes, the second is a social scent that produces ovules during the breeding season, described as smelling like tangerines.

This odor originates from tiny wit feathers located on a small patch of skin between the tiny blades. In winter plumage, their bills are smaller and dull yellow they lack accessory plates and their crest and auricular plumes are depleted.

Adolescents are like winter adults but without auricular and crest plumes. Their bills are shorter and have a light brown color. Adolescents take 33 days to reach adult size.

Distribution and Accommodation

Crested auklets are found throughout the North Pacific and the Bering Sea. These are especially prevalent in the non-fertile winter months throughout the Aleutian Islands, Kuril Islands, and the Russian island of Sakhalin. They travel to the Okhotsk Sea and Bering Sea islands and breeding sites along the coast in late spring and summer.

Their habitat consists of opals, boulder fields, lava flows, and sea peaks. They are often found in other auklet species, such as minimum owlets. On a daily basis, crest owls are circulated 500 meters above sea and breeding colonies. This cycle has become the cause of turmoil and threats by predators.

Behavior and Ecology

Simple food

Crested auklet is primarily grazing in deep water, but sometimes in areas near the shore, but always in large herds. Little is known about winter diets, but it is suggested that they feed on various marine electronic signals. Crested auklets are planktivores.

Their diet consists mainly of krill but is also known to eat copepods, terpods (such as Limacina), amphipods and larval fish. Eager owls let their food sink to the surface of the water to catch it. This behavior has been described as a submerged “aircraft”.

Fertility and parental care

The Crested auklet's breeding season begins in mid-May and ends in mid-August. Their nest sites are in the rocky grooves of the North Pacific coast. They breed in dense colonies of a million birds. Because of this, the nest sites are located close to the nest, with about 0.3 m in the nest.

Nevertheless, there are higher sectional areas, and adults show high site reliability within a year. Since mating occurs at sea and men have no controlling organs, males must rotate over their wives in order to achieve success. Spouse choices are mutual, but wives have the ultimate choice of a breeding partner.

Crested auklet meets during the breeding season, before the formation of twins and in the highly social breeding years after the formation of twins, the Crested auklets are exclusive, with only 10% of the extra pair population.

Partners continue to self-advertise with other birds when they do not encourage them. There may be links to some of these advertising behaviors.

Although some of these advertising behaviors may be linked to extra pairing, it is recommended that the continuation of the behavior allow the birds to find pairs in the next breeding season. In the next breeding season, only 45.5% of the birds are with the same partner.

Both genders invest high in parental care; Parents have an equal share in hatching single eggs and raising chickens. Since both genders are rhetorical, eager owls have been integrated with Robert Travers's theory of patriarchal investment, which predicts that mutual choice will arise with bipolar care.

Sexual selection

Crested auklets are unique in their use of optical, vocal and wolf factory signals in the confluence. Their communicative behavior is more complex and diverse than the closely related species. There are three general evolutionary methods proposed to address the wide spectrum of Crested auklet and to address the source of signals of mating in general by men.

Visual ornaments

The dominance of the category regarding the claimed display area has been related to the Crested auklet length in both males and females. The existence of these attractive monomorphic traits indicates intense sexual selection for both sexes.

Adults receiving larger crests of both sexes exhibit higher levels of sexual interest and opposite sex than smaller Crested auklets. Larger Crested auklets are more likely to partner and form bonds earlier.

Based on divorce rates and deaths, more than half find a new partner every year. Female Crested auklet's length is the primary factor in switching male mates over the years.

Although there are differences in displays across the population, Crested auklet plum ornaments are consistent with expression within a person over time.

The voice is rhetorical

There are several types of single and complex voices to Crested auklets. Billing is defined as “Pair Courtship with Mutual Cackling Vocal Display.” This is an important part of a successful pairing and it becomes harmonious once the male and female partners are well known.

Trumpet calls are the most common calls. The call presents a complex but stereotyped vocal sequence that is linked to a specific visual display. Within individuals, calls vary in duration and frequency. Voices are made primarily in men, but also in girls. The call is especially strong among widows.

Decorations are ornaments

Crested auklets have a distinct citrus-like plumage flavor. If the threat, horn or billing display shakes the nape of the person and feathers on the top, the scent is revealed. The published olfactory cloud promotes a rough sniff display.

A Roof sniff is displayed when the birds completely bury their half-open bill on the other's plumage. This display occurs in the absence of clear aggression and is important for pair formation. For both sexes, a strong odor attracts more people, which later exhibits a rough sniff.

The odor emission increases during the breeding season, highlighting its relationship with courtship and mate selection. The aroma can also act as an ectoparasite antagonist. This flavor is also found in whisked owls.

Conservation status

Crested auklets are of less concern, according to the International Union for Conservation of Nature. The global population exceeds 1.2 million people, while North America has a population of 2.5 million birds.

However, it is difficult to make an accurate assessment of the number of birds, since the variable and poor burden on the colonies' surface and surrounding seas constitute a small proportion of the population.

There is a greater concern for the Alaskan population. High prey was reported by rats escaping from fishing vessels at the port. The main predators of owls are the gulls, Arctic foxes, and the common crow.

They were also reported to be in the abdomen of halibut caught on St. Lawrence Island. Oil spills and collisions with light sources pose an additional risk. There are some species of livelihoods in Alaska.

Watch the video: Большие конюги (February 2021).

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