Crest (feathers)

The crest is a prominent feature exhibited by several bird and other dinosaur species on their heads.

The crest is made up of semiplume feathers: a long rachis with barbs on either side. These are plumulaceous feathers, meaning that they are soft and bendable. In birds, these semiplumes are common along the head, neck, and upper back, and may be used for buoyancy and sensing vibrations.

Crests on birds are generally used for display purposes. Cockatoos and their smaller cousins, cockatiels, are part of the parrot family Cacatuidae found in Australia, the Bismarck Archipelago and the Philippines, and are probably the most recognizable birds to feature crests.[1] Cockatoos and cockatiels possess crests which may be raised or lowered at will. Their crests are used to communicate with fellow members of their species, or as a form of defense to frighten away other species that approach too closely, making the bird appear larger when the crest is suddenly and unexpectedly raised.[2] Crests can be recumbent or recursive, depending on the species.[3] The recumbent crest has feathers that are straight and lie down essentially flat on the head until the bird fans them out to where they stand up. The white cockatoo, for example, possesses a recumbent crest.[3] The recursive crest is noticeable even when it is not fanned out because it features feathers, that, when lying down, curve upward at the tips, and when standing up, often bend slightly forward toward the front of the head. Many recursive crests also feature brilliant colors. The sulphur-crested cockatoo has a recursive crest, and the Major Mitchell's cockatoo (also known as the Leadbeater's cockatoo) possesses a prominent recursive crest.[2] Some birds, like the galah, or rose-breasted cockatoo, have modified crests, which has features of both recumbent and recursive types.[2]

Many domesticated bird species have crest feathers. These structures are known to have two origins: selective breeding or mutations. Crest feathers in domestic birds include a wide range of variations in form across species. The underlying molecular and genetic mechanisms that are responsible for crest feather formation in domesticated bird species are not well understood. As such, crest feathers are widely studied in morphological research and other related biological disciplines, particularly concerning domesticated species.[4]

Balearica regulorum portrait 3
The grey crowned crane - an example of a crested bird species

Gallery

Citron crest feathers

Citron-crested cockatoo crest feathers (on 1 cm grid)

Umbrella Cockatoo (Cacatua alba) -Free Flight Aviary -San Diego

Umbrella cockatoo displaying

Female Galah Outside Nest

Female galah displaying

See also

References

  1. ^ Roberson, Don. "COCKATOOS Cacatuidae". Bird Families of the World. Retrieved 2 May 2013.
  2. ^ a b c Highfill, Carol. "Those Magnificent Cockatoo Crests". Cockatoo Heaven. Retrieved 2 May 2013.
  3. ^ a b Moustaki, Nikki (2005). Parrots for Dummies (1st ed.). Indianapolis, IN: Wiley Pub. ISBN 978-0764583537.
  4. ^ Bartels, Thomas (2003). "Variations in the morphology, distribution, and arrangement of feathers in domesticated birds". Journal of Experimental Zoology Part B: Molecular and Developmental Evolution. 298: 91–108. doi:10.1002/jez.b.28. PMID 12949771.
Comb (anatomy)

A comb is a fleshy growth or crest on the top of the head of gallinaceous birds, such as turkeys, pheasants, and domestic chickens. Its alternative name cockscomb (with several spelling variations) reflects that combs are generally larger on males than on females (a male gallinaceous bird is called a cock). There can be several fleshy protuberances on the heads and throats of gallinaceous birds, i.e. the comb, wattle, and earlobe, which collectively are called caruncles, however, in turkeys caruncle refers specifically to the fleshy nodules on the head and throat.

Chicken combs are most commonly red (but may be black or dark purple in breeds such as Silkies or Sebrights), but in other species the color may vary from light grey to deep blue or red; turkey combs can vary in color from bright red to blue.

The comb may be a reliable indicator of health or vigor and is used for mate-assessment in some poultry species.

Crest (anatomy)

A crest is any of various anatomical features appearing as a raised point or ridge, most prominently those on the head or back of an animal.

A part of a bone:

Sagittal crest

Cnemial crest

Iliac crest

Frontal crest

Infratemporal crest

Anterior lacrimal crest

Posterior lacrimal crest

Buccinator crest

A feature on various animals:

Crest (feathers)

Display feature or thermoregulatory feature in various reptiles

Sail (anatomy), also known as crest in some animals

The point of a horse's neck where the mane grows from

Neural crest, a temporary group of cells unique to vertebrates that arise from the embryonic ectoderm cell layer

Crested auklet

The crested auklet (Aethia cristatella) is a small seabird of the family Alcidae, distributed throughout the northern Pacific and the Bering Sea. The species feeds by diving in deep waters, eating krill and a variety of small marine animals. It nests in dense colonies of up to 1 million individuals in the Bering Sea and the Sea of Okhotsk. It often breeds in mixed-species colonies with the least auklet, a smaller congener.

The species is known for its sexual ornaments, found in both males and females. These include colorful plumage with a forehead crest, a striking scent recalling citrus fruit, and a loud trumpet call, all of which appear to have evolved through sexual selection. The total population is around 6 million, almost half in North America. It is in general considered to be of least concern, though the Alaskan population faces additional threats from predation and oil spills.

Crested bobwhite

The crested bobwhite (Colinus cristatus) is a species of bird in the family Odontophoridae. It is found in northern South America, extending through Panama to just reach Costa Rica. It also occurs on Aruba and the Netherlands Antilles. Its natural habitats are subtropical or tropical dry shrubland, subtropical or tropical seasonally wet or flooded lowland grassland, and heavily degraded former forest.

Goldcrest

The goldcrest (Regulus regulus) is a very small passerine bird in the kinglet family. Its colourful golden crest feathers, as well as being called the "king of the birds" in European folklore, gives rise to its English and scientific names. The scientific name, R. regulus, means king or knight. Several subspecies are recognised across the very large distribution range that includes much of Eurasia and the islands of Macaronesia and Iceland. Birds from the north and east of its breeding range migrate to winter further south.

This kinglet has greenish upper-parts, whitish under-parts, and has two white wingbars. It has a plain face contrasting black irises and a bright head crest, orange and yellow in the male and yellow in the female, which is displayed during breeding. It superficially resembles the common firecrest, which largely shares its European range, but the latter's bronze shoulders and strong face pattern are distinctive. The song is a repetition of high thin notes, slightly higher-pitched than those of its relative. Birds on the Canary Islands are now separated into two subspecies of the goldcrest, but were formerly considered to be a subspecies of the firecrest or a separate species, Regulus teneriffae.

The goldcrest breeds in coniferous woodland and gardens, building its compact, three-layered nest on a tree branch. Ten to twelve eggs are incubated by the female alone, and the chicks are fed by both parents; second broods are common. This kinglet is constantly on the move as it searches for insects to eat, and in winter it is often found with flocks of tits. It may be killed by birds of prey or carry parasites, but its large range and population mean that it is not considered to present any significant conservation concerns.

Horned parakeet

The horned parakeet (Eunymphicus cornutus) is a species of parrot in the genus Eunymphicus, in the family Psittaculidae. Eunymphicus cornutus is a medium-sized parrot endemic to New Caledonia. It is called "horned" because it has two black feathers that protrude from the head and have red tips.

Marvellous spatuletail

The marvellous spatuletail (Loddigesia mirabilis) is a medium-sized (up to 15 cm long) white, green and bronze hummingbird adorned with blue crest feathers, a brilliant turquoise gorget, and a black line on its white underparts. It is the only member of the monotypic genus Loddigesia. It is sexually dimorphic.

A Peruvian endemic, this species is found on forest edges in the Río Utcubamba region. It was first reported in 1835 by the bird collector Andrew Matthews for George Loddiges, after whom the genus is named.

The marvellous spatuletail is unique among birds in having just four feathers in its tail. Its most remarkable feature is the male's two long racquet-shaped outer tail feathers that cross each other and end in large violet-blue discs or "spatules". He can move them independently.

Due to habitat loss, small population size, and limited range, the marvellous spatuletail is evaluated as Endangered on the IUCN Red List of Threatened Species. It is listed on Appendix II of CITES.

In 2006, American Bird Conservancy provided Peruvian conservation partner ECOAN with support to sign a conservation easement with the Pomacochas Community to protect and manage about 100 acres (0.40 km2) of significant habitat for the marvelous spatuletail hummingbird. Over 30,000 saplings of native trees and bushes have been planted there for the marvelous spatuletail. This conservation easement is the first of its kind in Peru.The marvellous spatuletail has been featured on the PBS TV series Nature and the BBC TV series Natural World.

Outline of birds

The following outline is provided as an overview of and topical guide to birds:

Birds (class Aves) – winged, bipedal, endothermic (warm-blooded), egg-laying, vertebrate animals. There are around 10,000 living species, making them the most varied of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from the 5 cm (2 in) bee hummingbird to the 2.75 m (9 ft) ostrich.

Palm cockatoo

The palm cockatoo (Probosciger aterrimus), also known as the goliath cockatoo or great black cockatoo, is a large smoky-grey or black parrot of the cockatoo family native to New Guinea, Aru Islands, and Cape York Peninsula. It has a very large black beak and prominent red cheek patches.

Peruvian pelican

The Peruvian pelican (Pelecanus thagus) is a member of the pelican family. It lives on the west coast of South America, breeding in loose colonies from about 33.5° in central Chile to Piura in northern Peru, and occurring as a visitor in southern Chile and Ecuador.These birds are dark in colour with a white stripe from the top of the bill up to the crown and down the sides of the neck. They have long tufted feathers on the top of their heads. It was previously considered a subspecies of the brown pelican (Pelecanus occidentalis). The Peruvian pelican is considerably larger, ranging from about 5 to 7 kg (11–15 lb) in weight, 137 to 152 cm (4.5–5.0 ft) in length and with a wingspan of about 228 cm (7.5 ft). Compared to the brown pelican, it also has proportionally longer crest feathers, as well as differences in the colours of the gular pouch, beak, scapulars and greater wing coverts.The main breeding season occurs from September to March. Clutch size is usually two or three eggs. Eggs are incubated for approximately 4 to 5 weeks, with the rearing period lasting about 3 months.

This bird feeds on several species of fish. Unlike the brown pelican, it never dives from a great height to catch it food, instead diving from a shallow height or feeding while swimming on the surface. On occasion it may take other food items, such as nestling of imperial shags, young Peruvian diving petrels, gray gulls and cannibalize unrelated chicks its own species.Its status was first evaluated for the IUCN Red List in 2008, being listed as Near threatened.

Petrockstowe

Petrockstowe (or Petrockstow) is a small village and civil parish in the district of Torridge in Northern Devon, England. Its population in 2001 was 379, hardly different from the figure of 385 recorded in 1901. The southern boundary of the parish lies on the River Torridge, and it is surrounded, clockwise from the north, by the parishes of Peters Marland, Merton, Huish, Meeth, Highampton and Buckland Filleigh.The village lies about four miles NNW of the town of Hatherleigh and is some two miles west of the A386 road, accessible only by minor roads.

Reddish egret

The reddish egret (Egretta rufescens) is a medium-sized heron. It is a resident breeder in Central America, The Bahamas, the Caribbean, the Gulf Coast of the United States, and Mexico. There is post-breeding dispersal to well north of the nesting range. In the past, this bird was a victim of the plume trade.

According to the Texas Parks and Wildlife Department, there are only 1,500 to 2,000 nesting pairs of reddish egrets in the United States — and most of these are in Texas. They are classified as "threatened" in Texas and receive special protection.

Rhynochetos

Rhynochetos is a genus of ground-dwelling birds in the Kagu family. It contains two species, both endemic to New Caledonia, one of which is extinct.

Siamese fireback

The Siamese fireback (Lophura diardi) also known as Diard's fireback, is a fairly large, approximately 80 cm long, pheasant. The male has a grey plumage with an extensive facial caruncle, crimson legs and feet, ornamental black crest feathers, reddish brown iris and long curved blackish tail. The female is a brown bird with blackish wing and tail feathers.

The Siamese fireback is distributed to the lowland and evergreen forests of Cambodia, Laos, Thailand and Vietnam in Southeast Asia. This species is also designated as the national bird of Thailand. The female usually lays between four and eight rosy eggs.

The scientific name commemorates the French naturalist Pierre-Médard Diard.

Suzanne Amador Kane

Suzanne Amador Kane is a physicist and Professor and Chair of Physics and Astronomy at Haverford College. She is well known for her work utilizing video to understand the behavior of various species of birds.

Tanimbar corella

The Tanimbar corella (Cacatua goffiniana) also known as Goffin's cockatoo or Goffin's corella, is a species of cockatoo endemic to forests of Yamdena, Larat and Selaru, all islands in the Tanimbar Islands archipelago in Indonesia. The species has been introduced to the Kai Islands, Indonesia, Puerto Rico and Singapore. This species was only formally described in 2004, after it was discovered that the previous formal descriptions pertained to individuals of a different cockatoo species, the Ducorps' or Solomons cockatoo (Cacatua ducorpsii). Tanimbar corellas are the smallest of the white cockatoos. This species is Near Threatened due to deforestation and bird trade. The species breeds well in captivity and there is a large avicultural population.

White cockatoo

The white cockatoo (Cacatua alba), also known as the umbrella cockatoo, is a medium-sized all-white cockatoo endemic to tropical rainforest on islands of Indonesia. When surprised, it extends a large and striking head crest, which has a semicircular shape (similar to an umbrella, hence the alternative name). The undersides of the wings and tail have a pale yellow or lemon color which flashes when they fly. It is similar to other species of white cockatoo such as yellow-crested cockatoo, sulphur-crested cockatoo, and salmon-crested cockatoo, all of which have yellow, orange or pink crest feathers instead of white.

Cockatoos (family: Cacatuidae)
Appearance
Small
Black
Pink or grey
White

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