1.
Blue-and-yellow macaw
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The blue-and-yellow macaw, also known as the blue-and-gold macaw, is a large South American parrot with blue top parts and yellow under parts. It is a member of the group of neotropical parrots known as macaws. It inhabits forest and woodland of tropical South America and they are popular in aviculture because of their striking color, ability to talk, ready availability in the marketplace, and close bonding to humans. The blue-and-yellow macaw is a member of the genus Ara, one of six genera of Central, the species name is derived from Tupi ara onamatopoeia macao, macaw, Tupi arara, parrot +una, dark or black, hence dark parrot/macaw. These birds can reach a length of 76–86 cm and weigh 0. 900–1.5 kg and they are vivid in appearance with blue wings and tail, dark-blue chin, golden under parts, and a green forehead. The naked face is white, turning pink in excited birds, Blue-and-yellow macaws live from 30 to 35 years in the wild and reach sexual maturity between the ages of 3 and 6 years. Little variation in plumage is seen across the range, some birds have a more orange or butterscotch underside color, particularly on the breast. This was often seen in Trinidad birds and others of the Caribbean area, the blue-and-yellow macaw uses its powerful beak for breaking nutshells, and for climbing up and hanging from trees. This species occurs in Venezuela, Peru, Brazil, Bolivia, the range extends slightly into Central America, where it is restricted to Panama. The species range formerly included Trinidad, but it became extinct there by 1970 as a result of human activities, between 1999 and 2003, wild-caught blue-and-gold macaws were translocated from Guyana to Trinidad, in an attempt to re-establish the species in a protected area around Nariva swamp. A small breeding population descended from introduced birds is found in Puerto Rico, the blue-and-yellow macaw generally mates for life. They nest almost exclusively in dead palms and most nests are in Mauritia flexuosa palms, the female typically lays two or three eggs. The female incubates the eggs for about 28 days, one chick is dominant and gets most of the food, the others perish in the nest. Chicks fledge from the nest about 97 days after hatching, the male birds color signals readiness for breeding. The brighter and bolder the colors, the better the chance of getting a mate, the blue-and-yellow macaw is on the verge of being extirpated in Paraguay, but it still remains widespread and fairly common in a large part of mainland South America. The species is listed as Least Concern by BirdLife International. It is listed on CITES Appendix II, trade restricted and they are very intelligent and social birds that bond very closely to their owners, however, so for people who are able to provide for their needs, they make great and loving companion parrots. Even well-tended blue-and-yellow macaws are known to scream and make loud noises
2.
Scarlet macaw
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The scarlet macaw is a large red, yellow, and blue South American parrot, a member of a large group of Neotropical parrots called macaws. It is native to humid forests of tropical South America. Range extends from south-eastern Mexico to the Peruvian Amazon, Colombia, Bolivia, Venezuela and it has suffered from local extinction through habitat destruction and capture for the parrot trade, but locally it remains fairly common. Formerly it ranged north to southern Tamaulipas and it can still be found on the island of Coiba. It is the bird of Honduras. The scarlet macaw is a member of the genus Ara, one of 6 genera of Central, carolus Linnaeus described and named the scarlet macaw in his Systemae Naturae in 1758. Both subspecies can be recognized by size and color detail in the feathers on the wings, a. macao macao South American scarlet macaw, the nominate subspecies. In the wings the medium and secondary coverts have green tip, a. macao cyanoptera North Central American scarlet macaw. The Central American scarlet macaw is larger and has blue on its wings instead of green. It is about 81 centimetres long, of more than half is the pointed, graduated tail typical of all macaws. The average weight is about 1 kilogram, some individuals may have green in the wings. There is bare white skin around the eye and from there to the bill, tiny white feathers are contained on the face patch. The upper mandible is mostly pale horn in color and the lower is black, juveniles have dark eyes, adults have light yellow eyes. It is frequently confused with the slightly larger green-winged macaw, which has distinct red lines in the face. Scarlet macaws make very loud, high and sometimes low-pitched, throaty squawks, squeaks, the scarlet macaw can live up to 75 years in captivity, although a more typical lifespan is 40 to 50 years. In May 2013 it was announced that a team of scientists, led by Dr. Christopher M. Seabury, a typical sighting is of a single bird or a pair flying above the forest canopy, though in some areas flocks can be seen. They may gather at clay licks, Scarlet macaws communicate primarily through raucous honks, however, vocal communication is highly variable, and captive macaws are known to be adept mimics of human speech. Scarlet macaws eat mostly fruits, nuts and seeds, including large, while comparatively docile at most times of the year, scarlet macaws may be formidably aggressive during periods of breeding
3.
Bird
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Birds, a subgroup of Reptiles, are the last living examples of Dinosaurs. Birds live worldwide and range in size from the 5 cm bee hummingbird to the 2.75 m ostrich. They rank as the class of tetrapods with the most living species, at ten thousand. Birds are the closest living relatives of crocodilians, the fossil record indicates that birds evolved from feathered ancestors within the theropod group of saurischian dinosaurs. True birds first appeared during the Cretaceous period, around 100 million years ago, Birds, especially those in the southern continents, survived this event and then migrated to other parts of the world while diversifying during periods of global cooling. Primitive bird-like dinosaurs that lie outside class Aves proper, in the broader group Avialae, have been found dating back to the mid-Jurassic period, around 170 million years ago. Birds have wings which are more or less developed depending on the species, the digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have evolved for swimming. Many species annually migrate great distances, Birds are social, communicating with visual signals, calls, and bird songs, and participating in such social behaviours as cooperative breeding and hunting, flocking, and mobbing of predators. The vast majority of species are socially monogamous, usually for one breeding season at a time, sometimes for years. Other species have breeding systems that are polygynous or, rarely, Birds produce offspring by laying eggs which are fertilised through sexual reproduction. They are usually laid in a nest and incubated by the parents, most birds have an extended period of parental care after hatching. Some birds, such as hens, lay eggs even when not fertilised, songbirds, parrots, and other species are popular as pets. Guano is harvested for use as a fertiliser, Birds prominently figure throughout human culture. About 120–130 species have become extinct due to human activity since the 17th century, human activity threatens about 1,200 bird species with extinction, though efforts are underway to protect them. Recreational birdwatching is an important part of the ecotourism industry, the first classification of birds was developed by Francis Willughby and John Ray in their 1676 volume Ornithologiae. Carl Linnaeus modified that work in 1758 to devise the taxonomic classification system currently in use, Birds are categorised as the biological class Aves in Linnaean taxonomy. Phylogenetic taxonomy places Aves in the dinosaur clade Theropoda, Aves and a sister group, the clade Crocodilia, contain the only living representatives of the reptile clade Archosauria
4.
Species
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In biology, a species is the basic unit of biological classification and a taxonomic rank. A species is defined as the largest group of organisms in which two individuals can produce fertile offspring, typically by sexual reproduction. While this definition is often adequate, looked at more closely it is problematic, for example, with hybridisation, in a species complex of hundreds of similar microspecies, or in a ring species, the boundaries between closely related species become unclear. Other ways of defining species include similarity of DNA, morphology, all species are given a two-part name, a binomial. The first part of a binomial is the genus to which the species belongs, the second part is called the specific name or the specific epithet. For example, Boa constrictor is one of four species of the Boa genus, Species were seen from the time of Aristotle until the 18th century as fixed kinds that could be arranged in a hierarchy, the great chain of being. In the 19th century, biologists grasped that species could evolve given sufficient time, Charles Darwins 1859 book The Origin of Species explained how species could arise by natural selection. Genes can sometimes be exchanged between species by horizontal transfer, and species may become extinct for a variety of reasons. In his biology, Aristotle used the term γένος to mean a kind, such as a bird or fish, a kind was distinguished by its attributes, for instance, a bird has feathers, a beak, wings, a hard-shelled egg, and warm blood. A form was distinguished by being shared by all its members, Aristotle believed all kinds and forms to be distinct and unchanging. His approach remained influential until the Renaissance, when observers in the Early Modern period began to develop systems of organization for living things, they placed each kind of animal or plant into a context. Many of these early delineation schemes would now be considered whimsical, animals likewise that differ specifically preserve their distinct species permanently, one species never springs from the seed of another nor vice versa. In the 18th century, the Swedish scientist Carl Linnaeus classified organisms according to shared physical characteristics and he established the idea of a taxonomic hierarchy of classification based upon observable characteristics and intended to reflect natural relationships. At the time, however, it was widely believed that there was no organic connection between species, no matter how similar they appeared. However, whether or not it was supposed to be fixed, by the 19th century, naturalists understood that species could change form over time, and that the history of the planet provided enough time for major changes. Jean-Baptiste Lamarck, in his 1809 Zoological Philosophy, described the transmutation of species, proposing that a species could change over time, in 1859, Charles Darwin and Alfred Russel Wallace provided a compelling account of evolution and the formation of new species. Darwin argued that it was populations that evolved, not individuals and this required a new definition of species. Darwin concluded that species are what appear to be, ideas
5.
Hybrid (biology)
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In biology, a hybrid, also known as a cross breed, is the result of combining, through sexual reproduction, the qualities of two animals or plants of different breeds, varieties, species or genera. Hybrids are not always intermediate between their parents, but can show heterosis or hybrid vigour, often growing larger or taller than either parent, some act before fertilization, others after it. A few animal species and many plant species, however, are the result of hybrid speciation, doubling the number of chromosomes to create polyploids is important in hybrid speciation, because homoploid hybrids are rarely fertile, the polyploid hybrids are allopolyploids. Human impact on the environment has greatly increased the mixing of species, with introduced species worldwide, the genetic mixing may threaten many species with extinction, while genetic erosion in crop plants may be damaging the gene pools of many species for future breeding. Many commercially useful fruits, flowers, garden herbs and trees have been produced by hybridization, one flower, Oenothera lamarckiana, was central to early genetics research into polyploidy. The term hybrid is derived from Latin hybrida, used for such as of a tame sow and a wild boar, or the child of a freeman. The term came into use in English in the 19th century. Conspicuous hybrids are named with portmanteau words, starting in the 1920s with the breeding of tiger-lion hybrids. The cross between two different homozygous lines produces an F1 hybrid that is heterozygous, having two alleles, one contributed by each parent and typically one is dominant and the other recessive. Typically, the F1 generation is also phenotypically homogeneous, producing offspring that are all similar to each other, double cross hybrids result from the cross between two different F1 hybrids. Three-way cross hybrids result from the cross between an F1 hybrid and an inbred line, triple cross hybrids result from the crossing of two different three-way cross hybrids. Top cross hybrids result from the crossing of a top quality or pure-bred male, population hybrids result from the crossing of plants or animals in a population with those of another population. These include interspecific hybrids or crosses between different breeds. e, from the point of view of genetics, different kinds of hybrid can be distinguished as follows, A genetic hybrid carries two different alleles of the same gene. A structural hybrid results from the fusion of gametes that have differing structure in at least one chromosome, a numerical hybrid results from the fusion of gametes having different haploid numbers of chromosomes. A permanent hybrid results when only the heterozygous genotype occurs, as in Oenothera lamarckiana, from the point of view of taxonomy, hybrids differ according to their parentage, Hybrids between different subspecies are called intra-specific hybrids. Offspring resulting from interspecies mating, are called interspecific hybrids, these result in hybrid speciation. Intergeneric hybrids result from matings between different genera, such as sheep and goats. Interfamilial hybrids such as chickens and guineafowl or pheasants are reliably described but extremely rare
6.
British finches
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The British finches are made up of several species of finch which were formerly very popular as cage birds in Great Britain. They are not currently commonplace, but are kept by a few dedicated fanciers. In Victorian times British finches were hugely popular as cage birds throughout the British Isles, due to a lack of protection, thousands of birds were captured for the pet trade every year. Their popularity is reflected in the well-known British music hall song, My Old Man, in the line, I walked behind wiv me old cock linnet. British finches are often associated with mules, a used by cage bird breeders to refer to hybrids of finch species bred in captivity, such as that of a goldfinch. There are now strict ringing regulations on British finches in places such as the UK, the seed mixture in the UK known as British Finch & Mule is their basic diet. British finches are quite simply birds in the family which to this day live wild in the British Isles. g. A goldfinch, was crossed with a canary, the result was an attractive looking, the resulting birds were sterile, but continue to be bred to this day under the name of mules. Also around this time a few began to experiment crossing British finches. The resulting birds, including siskin × goldfinch and even such beauties as crossbill × Eurasian bullfinch also remain to this day, the breeding of such hybrids can, however be notoriously difficult. When writing about hybrid pairs, the cock always comes first, list of birds of Great Britain British Birds in Aviculture
7.
Gamebird hybrids
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Gamebird hybrids are the result of crossing species of game birds, including ducks, with each other and with domestic poultry. These hybrid species may occur naturally in the wild or more commonly through the deliberate or inadvertent intervention of humans. Utterly sterile male hybrids from the pheasant and the act in the same manner, their delight being to watch when the hens leave their nests. Mr. Hewitt gives it as a rule with fowls. Hybrids have been obtained between the species of pheasants e. g. Lady Amhersts, silver and Reevess pheasants. In her book Bird Hybrids, A. P. Gray lists numerous crosses between chickens and other types of fowl, domestic fowl can be crossed, and produce fertile offspring, with silver pheasants, red junglefowl and green junglefowl. They have also produced hybrids with peafowl, chachalacas, capercaillie, grouse, quail, curassows, pheasants, domestic fowl have been crossed with guineafowl and also with common pheasant. Domestic fowl/pheasant hybrids have also occurred naturally, domestic chickens and Japanese quail have been hybridised using artificial insemination. The peafowl from Asia and the common guineafowl from Africa have been crossed, there have been attempted crosses between domestic turkeys and chickens. According to Gray in 12 studies no hybrids hatched, other reports found only a few fertile eggs were produced and very few resulted in advance embryos. According to Olsen,23 hybrids were obtained from 302 embryos which resulted from 2132 eggs, dark Cornish cockerels and Rhode Island Red cockerels successfully fertilised turkey eggs. Harada & Buss reported hybridisation experiments between Beltsville Small White Turkeys and two strains of chickens, when male chickens inseminated female turkeys, both male and female embryos form, but the males are much less viable and usually die in the early stages of development. When male turkeys inseminated female chickens, no hybrids resulted although the unfertilised chicken eggs began to divide, according to Olson turkey-chicken crosses produced all males. A supposed turkey × pheasant hybrid was reported by Edwards in 1761, garnett observed that his hybrids were wild, and exhibited migratory propensities of which there is not a vestige in the common or musk duck. Hybrids between mallard ducks and Aylesbury ducks are seen in British parks where the two types are present. The hybrids often resemble a dark coloured mallard with a white breast, mallard ducks also hybridise with the Muscovy duck producing pied offspring. Hybrids between the ruddy duck and white-headed duck are undesirable in parts of Europe where the introduced ruddy duck has bred with native white-headed ducks, the increasing number of ruddy ducks and hybrids threatens the existence of the white-headed ducks, resulting in shooting campaigns to remove the introduced species. This is controversial as some believe that nature should be allowed to take its course, Hybrid ducks of the genus Aythya, include birds which are a mixture of tufted duck, greater scaup, pochard, ferruginous duck and ring-necked duck
8.
Intergeneric hybrid
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In biology, a hybrid, also known as a cross breed, is the result of combining, through sexual reproduction, the qualities of two animals or plants of different breeds, varieties, species or genera. Hybrids are not always intermediate between their parents, but can show heterosis or hybrid vigour, often growing larger or taller than either parent, some act before fertilization, others after it. A few animal species and many plant species, however, are the result of hybrid speciation, doubling the number of chromosomes to create polyploids is important in hybrid speciation, because homoploid hybrids are rarely fertile, the polyploid hybrids are allopolyploids. Human impact on the environment has greatly increased the mixing of species, with introduced species worldwide, the genetic mixing may threaten many species with extinction, while genetic erosion in crop plants may be damaging the gene pools of many species for future breeding. Many commercially useful fruits, flowers, garden herbs and trees have been produced by hybridization, one flower, Oenothera lamarckiana, was central to early genetics research into polyploidy. The term hybrid is derived from Latin hybrida, used for such as of a tame sow and a wild boar, or the child of a freeman. The term came into use in English in the 19th century. Conspicuous hybrids are named with portmanteau words, starting in the 1920s with the breeding of tiger-lion hybrids. The cross between two different homozygous lines produces an F1 hybrid that is heterozygous, having two alleles, one contributed by each parent and typically one is dominant and the other recessive. Typically, the F1 generation is also phenotypically homogeneous, producing offspring that are all similar to each other, double cross hybrids result from the cross between two different F1 hybrids. Three-way cross hybrids result from the cross between an F1 hybrid and an inbred line, triple cross hybrids result from the crossing of two different three-way cross hybrids. Top cross hybrids result from the crossing of a top quality or pure-bred male, population hybrids result from the crossing of plants or animals in a population with those of another population. These include interspecific hybrids or crosses between different breeds. e, from the point of view of genetics, different kinds of hybrid can be distinguished as follows, A genetic hybrid carries two different alleles of the same gene. A structural hybrid results from the fusion of gametes that have differing structure in at least one chromosome, a numerical hybrid results from the fusion of gametes having different haploid numbers of chromosomes. A permanent hybrid results when only the heterozygous genotype occurs, as in Oenothera lamarckiana, from the point of view of taxonomy, hybrids differ according to their parentage, Hybrids between different subspecies are called intra-specific hybrids. Offspring resulting from interspecies mating, are called interspecific hybrids, these result in hybrid speciation. Intergeneric hybrids result from matings between different genera, such as sheep and goats. Interfamilial hybrids such as chickens and guineafowl or pheasants are reliably described but extremely rare
9.
Canada goose
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The Canada goose is a large wild goose species with a black head and neck, white patches on the face, and a brown body. Native to arctic and temperate regions of North America, its migration occasionally reaches northern Europe and it has been introduced to the United Kingdom, New Zealand, Argentina, Chile, and the Falkland Islands. Like most geese, the Canada goose is primarily herbivorous and normally migratory, Canada geese are also among the most commonly hunted waterfowl in North America. The Canada goose was one of the species described by Carl Linnaeus in his 18th-century work Systema Naturae. It belongs to the Branta genus of geese, which species with largely black plumage. Branta is a Latinised form of Old Norse Brandgás, burnt goose, according to the Oxford English Dictionary, the first citation for the Canada goose dates back to 1772. The Canada goose is colloquially referred to as the Canadian goose. The British Ornithologists Union followed suit in June 2005, the AOU has divided the many subspecies between the two species. This has been aggravated by the overlap between the types of Canada goose and larger types of cackling goose. The old lesser Canada goose was believed to be a hybrid population, with the birds named B. c. taverneri considered a mixture of B. c. minima, B. c. occidentalis. In addition, the barnacle goose has been determined to be a derivative of the cackling goose lineage, the black head and neck with a white chinstrap distinguish the Canada goose from all other goose species, with the exception of the cackling goose and barnacle goose. The seven subspecies of this vary widely in size and plumage details. Some of the races can be hard to distinguish from the cackling goose. However, most subspecies of the goose are considerably smaller. The smallest cackling goose, B. h. minima, is larger than a mallard. In addition to the difference, cackling geese also have a shorter neck and smaller bill. Canada geese range from 75 to 110 cm in length and have a 127–185 cm wingspan. Among standard measurements, the chord can range from 39 to 55 cm, the tarsus can range from 6.9 to 10.6 cm
10.
Domestic goose
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Domestic geese are domesticated grey geese kept as poultry for their meat, eggs, and down feathers since ancient times. In Europe, northern Africa, and western Asia, the domesticated geese are derived from the greylag goose Anser anser. In eastern Asia, the domesticated geese are derived from the swan goose Anser cygnoides. Both have been introduced in more recent times, and modern flocks in both areas may consist of either species, and/or hybrids between them. Chinese geese may be distinguished from European geese by the large knob at the base of the bill. The domestication, as Charles Darwin remarks, is of ancient date. Although their heavy weight affects their ability to fly, most breeds of domestic geese are capable of flight, Geese have also been strongly selected for fecundity, with females laying up to 50 eggs per year, compared to 5–12 eggs for a wild goose. As most domestic geese display little sexual dimorphism, sexing is based primarily on physical characteristics, males are typically taller and larger than females, and have longer necks. In addition, males can be distinguished by the protective behaviour they exhibit towards their mate, changes to the plumage are variable, many have been selected to lose dark brown tones of the wild bird. The result is a marked, or completely covered in white feathers. Others retain plumage close to the natural, some, such as the modern Toulouse goose look almost identical to the greylag in plumage, white geese are often preferred as they look better plucked and dressed, with any small down feathers remaining being less conspicuous. From the time of the Romans, white geese have been held in great esteem, Geese produce large edible eggs, weighing 120–170 grams. They can be used in cooking just like chickens eggs, though they have more yolk. The taste is much the same as that of a chicken egg, like their wild ancestors, domestic geese are very protective of their offspring and other members of the flock. The gander will normally place himself between any perceived threat and his family, owing to their highly aggressive nature, loud call and sensitivity to unusual movements, geese can contribute towards the security of a property. In late 1950s South Vietnam, the VNAF used flocks of geese to guard their parked aircraft at night due to the noise they would make at intruders, when Aphrodite first came ashore she was welcomed by the Charites, whose chariot was drawn by geese. There are Mother Goose tales, such as a farmwife might have told, there is the goose that laid the golden eggs. The geese in the temple of Juno on the Capitoline Hill were said by Livy to have saved Rome from the Gauls around 390 BC when they were disturbed in a night attack
11.
Domestic canary
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The domestic canary, often simply known as the canary, is a domesticated form of the wild canary, a small songbird in the finch family originating from the Macaronesian Islands. Canaries were first bred in captivity in the 17th century and they were brought over by Spanish sailors to Europe. This bird became expensive and fashionable to breeding in courts of Spanish and English kings, monks started breeding them and only sold the males. This kept the birds in short supply and drove the price up, eventually Italians obtained hens and were able to breed the birds themselves. This made them popular and resulted in many breeds arising. First the birds were only owned by the rich but eventually the local citizens started to breed them and, again, many breeds arose through selective breeding, and they are still very popular today for their voices. Typically, the canary is kept as a popular cage. Given proper housing and care, a canarys lifespan ranges from 10 to 15 years, the birds are named after Spains Canary Islands, which derive their name from the Latin Insula Canaria, meaning island of dogs, due to its vast multitudes of dogs of very large size. Canaries are generally divided into three groups, Colour bred canaries Type canaries Song canaries. While wild canaries are a colour, domestic canaries have been selectively bred for a wide variety of colours, such as yellow, orange, brown, black, white. Canaries are judged in competitions following the annual molt in the summer and this means that in the Northern Hemisphere the show season generally begins in October or November and runs through December or January. Birds can only be shown by the person who raised them, a show bird must have a unique band on its leg indicating the year of birth, the band number, and the club to which the breeder belongs. There are many shows all over the world. The world show is held in Europe each year and attracts thousands of breeders, as many as 20,000 birds are brought together for this competition. Canaries were once used in coal mining as an early warning system. Toxic gases such as carbon monoxide or methane in the mine would kill the bird before affecting the miners, signs of distress from the bird indicated to the miners that conditions were unsafe. The use of canaries in British mines was phased out in 1986. The phrase canary in a mine is frequently used to refer to a person or thing which serves as an early warning of a coming crisis
12.
Galah
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It appears to have benefited from the change in the landscape since European colonisation and may be replacing the Major Mitchells cockatoo in parts of its range. The term galah is derived from gilaa, a found in Yuwaalaraay. Galahs are about 35 cm long and weigh 270–350 g and they have a pale silver to mid-grey back, a pale grey rump, a pink face and chest, and a light pink mobile crest. They have a beak, and the bare skin of the eye rings is carunculated. The sexes appear similar, however generally adult birds differ in the colour of the irises, the male has dark brown irises. The colours of the juveniles are duller than the adults, juveniles have greyish chests, crowns, and crests, and they have brown irises and whitish bare eye rings, which are not carunculated. Galahs are found in all Australian states, and are absent only from the driest areas and it is still uncertain whether they are native to Tasmania, though they are locally common today, especially in urban areas. They are common in metropolitan areas, for example Adelaide, Perth and Melbourne. Flocks of galahs will often congregate and forage on foot for food in open grassy areas, the classification of the galah was difficult. It was separated in the monotypic genus Eolophus, but the relationships were not clear. There are obvious similarities between the galah and the white cockatoos that make up the genus Cacatua and indeed the galah was initially described as Cacatua roseicapilla. Early DNA studies allied the galah with the cockatiel or placed it close to some Cacatua species of different appearance. It fell to the study of Brown & Toft to compare the available data with their mitochondrial 12S rRNA sequence research. The significance of these two shared by the Cacatuinae had previously been explained away in earlier studies by strict application of parsimony on misinterpreted data. There is slight variation in the colours of the plumage and in the extent of the carunculation of the eye rings among the three subspecies, most pet birds outside Australia are the south-eastern form. The galah nests in tree cavities, the eggs are white and there are usually two or five in a clutch. The eggs are incubated for about 25 days, and both the male and female share the incubation, the chicks leave the nest about 49 days after hatching. Living in captivity galahs can reach up to 70 to 80 years of age when a quality diet is strictly followed
13.
Little corella
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It was known as Birdirra among the Yindjibarndi people of the central and western Pilbara. They would keep them as pets, or traditionally cook and eat them, the downy feathers are used in traditional ceremonies and dances where they adorn head and armbands. The species was described by English ornithologist John Gould in 1843. It is easily distinguished from the long-billed corella by the lack of an orange throat bar, C. s. normantoni and C. s. normantoni are a little smaller than the nominate form. C. s. normantoni is lightly brownish on the underside of flight, C. s. gymnopis has darker blue eye-rings, more strongly marked pink lores and a yellow wash to the lower-ear coverts. Females are slightly smaller than males in weight, wing length, culmen size, tarsus length, tail length, the nominate form, C. s. sanguinea is found in Northern Australia. C. s. normantoni is found on the Western Cape York Peninsula, C. s. transfreta is found in New Guinea. C. s. gymnopis is found in Central, Eastern, habitat ranges from the arid deserts of central Australia to the eastern coastal plains, but they are not found in thick forests. Little corellas can also be found in areas, including Sydney and Brisbane. Little corellas congregate in flocks of up to several thousand, which include other birds such as galahs, sulfur-crested cockatoos. They generally roost in trees overnight, and fly off to feed in the morning before returning in the late evening. The call consists of high pitched notes and screeches somewhat similar to the sulfur-crested cockatoo, large flocks will call simultaneously and can create a deafening screeching sound audible from several kilometers away. Breeding occurs from May to October, and usually takes place earlier in the north of its range, the nest is usually in a tree hollow, cliff cavity or termite mound. Little corellas usually feed on the ground, however occasionally feed in trees and they eat a variety of both wild and cultivated seeds and regularly feed on lawn grasses in urban areas. They frequently feed on crops such as wheat, barley and corn. When little corellas play, they become very noisy and they have conversations with each other, fly around and also show off. Little corellas show off by hanging themselves upside-down with their feet, birds of Australia, Photographic Field Guide Sydney, Reed New Holland,2002. World Parrot Trust Parrot Encyclopedia - Species Profiles
14.
Lady Amherst's pheasant
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The Lady Amhersts pheasant is a bird of the order Galliformes and the family Phasianidae. The genus name is from Ancient Greek khrusolophos, with golden crest, however since late 2015 the species has been believed to be extinct in the wild in Great Britain with no confirmed sightings since March 2015. The adult male is 100–120 cm in length, its accounting for 80 cm of the total length. It is unmistakable with its nuchal cape white black, with a red crest, the long grey tail and rump is red, blue, dark green, white and yellow plumage. The cape can be raised in display and this species is closely related to the golden pheasant, but has a yellow eye, blue-green bare skin around it. The bill is horn-coloured and they had blue-gray legs, the female is much less showy, with a duller mottled brown plumage all over, similar to that of the female common pheasant but with finer barring. She is very like the golden pheasant, but has a darker head. Despite the males showy appearance, these birds are difficult to see in their natural habitat. Consequently, little is known of their behaviour in the wild and they feed on the ground on grain, leaves and invertebrates, but roost in trees at night. Whilst they can fly, they prefer to run, but if startled they can suddenly burst upwards at great speed, the male has a gruff call in the breeding season. Widespread throughout its range, the Lady Amhersts pheasant is evaluated as Least Concern on the IUCN Red List of Threatened Species. Included here is a closely related breed introduced to Britain in 19th century as Reevess pheasant. Neither the Reeves nor the similar Silver pheasant have Lady Amhersts very distinctive red cap, the Natural History of the British Isles. The Pocket Guide of British Birds
15.
Golden pheasant
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The golden pheasant or Chinese pheasant is a gamebird of the order Galliformes and the family Phasianidae. The genus name is from Ancient Greek khrusolophos, with golden crest, in England they may be found in East Anglia in the dense forest landscape of the Breckland as well as Tresco on the Isles of Scilly. The adult male is 90–105 cm in length, its accounting for two-thirds of the total length. It is unmistakable with its golden crest and rump and bright red body, the deep orange cape can be spread in display, appearing as an alternating black and orange fan that covers all of the face except its bright yellow eye with a pinpoint black pupil. Males have a golden-yellow crest with a hint of red at the tip, the face, throat, chin, and the sides of neck are rusty tan. The wattles and orbital skin are yellow in colour, and the ruff or cape is light orange. The upper back is green and the rest of the back, the tertiaries are blue whereas the scapulars are dark red. Other characteristics of the plumage are the central tail feathers, black spotted with cinnamon. The upper tail coverts are the colour as the central tail feathers. The male also has a scarlet breast, and scarlet and light chestnut flanks, lower legs and feet are a dull yellow. The female is less showy, with a duller mottled brown plumage similar to that of the female common pheasant. She is darker and more slender than the hen of that species, the females breast and sides are barred buff and blackish brown, and the abdomen is plain buff. She has a face and throat. Some abnormal females may later in their lifetime get some male plumage, lower legs and feet are a dull yellow. Both males and females have yellow legs and yellow bills, despite the males showy appearance, these hardy birds are very difficult to see in their natural habitat, which is dense, dark young conifer forests with sparse undergrowth. Consequently, little is known about their behaviour in the wild and they feed on the ground on grain, leaves and invertebrates, but they roost in trees at night. While they can fly clumsily in short bursts, they prefer to run, if startled, they can suddenly burst upwards at great speed and with a distinctive wing sound. Golden pheasants lay 8-12 eggs at a time and will then incubate these for around 22–23 days and they tend to eat berries, grubs, seeds and other types of vegetation
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Black grouse
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The black grouse or blackgame or blackcock is a large game bird in the grouse family. It is a species, breeding across northern Eurasia in moorland and bog areas near to woodland. The black grouse is closely related to the Caucasian grouse, the female is greyish-brown and has a cackling call. She takes all responsibility for nesting and caring for the chicks, the black grouses genome was sequenced in 2014. The black grouse is one of the species first described in the 10th edition of Systema Naturae in 1758 by Carl Linnaeus. Both Tetrao and tetrix come from Ancient Greek words referring to some form of game bird, the male and female are sometimes referred to by their folk names, blackcock and greyhen respectively. These names first occur in the literature with John Ray in 1674, heathcock and Heathhen are also common names. Black grouse is a bird with males being around 53 centimetres long and weighing 1, 000–1,450 g and females approximately 40 cm. The cock is very distinctive, with black plumage, apart from red wattles and a white wingbar, and a lyre-shaped tail and his song is loud, bubbling and somewhat dove-like. Black grouse can be found across Europe from Great Britain through Scandinavia and Estonia into Russia, in Eastern Europe they can be found in Hungary, Latvia, Lithuania, Poland, Belarus, Romania and Ukraine. There is a population in the Alps, and isolated remnants in Germany, France, Belgium and it formerly occurred in Denmark, but the Danish Ornithological Society has considered it extinct since 2001. The species disappeared from Bulgaria in the 19th century, although this species is declining in western Europe, it is not considered to be vulnerable globally due to the large population and slow rate of decline. Its decline is due to loss of habitat, disturbance, predation by foxes, crows, etc. the IUCN implemented a Black Grouse Action Plan 2007–2010. This has looked at local populations that are vulnerable to the extinction vortex, for example, in Styria in Austria. In the United Kingdom black grouse are found in areas of Wales. Best looked for on farmland and moorland with nearby forestry or scattered trees and they have traditional lek sites where the males display. They have declined in parts of the UK, having disappeared from many of their former haunts. They are now extirpated in Lancashire, Derbyshire, Exmoor, East Yorkshire, New Forest, Nottinghamshire, Worcestershire, Quantock Hills, Cornwall, Dartmoor, Kent, Wiltshire and Surrey
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Hazel grouse
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The hazel grouse, sometimes called the hazel hen, is one of the smaller members of the grouse family of birds. This is a relatively small grouse at 35–39 cm length, the plumage of this plump bird is finely patterned, but it essentially has grey upperparts, brown wings and chestnut flecked white underparts. The male has an erectile crest and a white-bordered black throat. The female has a shorter crest and lacks the black color on the throat, in flight, this species shows a black-tipped grey tail. The male has a high-pitched ti-ti-ti-ti-ti call, and the female a liquid tettettettettet and these calls, along with the burr of the flying birds wings, are often the only indication of this grouses presence, since its shyness and dense woodland habitat make it difficult to see. This bird feeds on the ground, taking mainly plant food, the nest is on the ground, and 3–6 eggs is the normal clutch size. The female incubates the eggs and cares for the chicks alone, birdLife species factsheet for Bonasa bonasia Tetrastes bonasia. Hazel grouse photo gallery at VIREO Interactive range map of Bonasa bonasia at IUCN Red List maps Audio recordings of Hazel grouse on Xeno-canto
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Polyploid
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Polyploid cells and organisms are those containing more than two paired sets of chromosomes. Most species whose cells have nuclei are diploid, meaning they have two sets of chromosomes—one set inherited from each parent, however, polyploidy is found in some organisms and is especially common in plants. In addition, polyploidy occurs in tissues of animals that are otherwise diploid. Species whose cells do not have nuclei, that is, Prokaryotes, may be polyploid organisms, hence ploidy is defined with respect to a cell. Most eukaryotes have diploid somatic cells, but produce haploid gametes by meiosis, a monoploid has only one set of chromosomes, and the term is usually only applied to cells or organisms that are normally diploid. Male bees and other Hymenoptera, for example, are monoploid, unlike animals, plants and multicellular algae have life cycles with two alternating multicellular generations. The gametophyte generation is haploid, and produces gametes by mitosis, polyploidy refers to a numerical change in a whole set of chromosomes. Organisms in which a particular chromosome, or chromosome segment, is under- or overrepresented are said to be aneuploid, polyploidy may occur due to abnormal cell division, either during mitosis, or commonly during metaphase I in meiosis. Polyploidy occurs in highly differentiated human tissues in the liver, heart muscle and it occurs in the somatic cells of some animals, such as goldfish, salmon, and salamanders, but is especially common among ferns and flowering plants, including both wild and cultivated species. Many agriculturally important plants of the genus Brassica are also tetraploids, oryzalin will also double the existing chromosome content. Polyploid types are labeled according to the number of sets in the nucleus. The letter x is used to represent the number of chromosomes in a single set, examples in animals are more common in non-vertebrates such as flatworms, leeches, and brine shrimp. Within vertebrates, examples of stable polyploidy include the salmonids and many cyprinids, some fish have as many as 400 chromosomes. Polyploidy also occurs commonly in amphibians, for example the biomedically-important Xenopus genus contains many different species with as many as 12 sets of chromosomes, polyploid lizards are also quite common, but are sterile and must reproduce by parthenogenesis. While mammalian liver cells are polyploid, rare instances of polyploid mammals are known, an octodontid rodent of Argentinas harsh desert regions, known as the plains viscacha rat has been reported as an exception to this rule. However, careful analysis using chromosome paints shows that there are two copies of each chromosome in T. barrerae, not the four expected if it were truly a tetraploid. This rodent is not a rat, but kin to guinea pigs and its new diploid number is 102 and so its cells are roughly twice normal size. Its closest living relation is Octomys mimax, the Andean Viscacha-Rat of the same family and it was therefore surmised that an Octomys-like ancestor produced tetraploid offspring that were, by virtue of their doubled chromosomes, reproductively isolated from their parents
19.
Punctuated equilibrium
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When significant evolutionary change occurs, the theory proposes that it is generally restricted to rare and geologically rapid events of branching speciation called cladogenesis. Cladogenesis is the process by which a species splits into two species, rather than one species gradually transforming into another. Punctuated equilibrium is commonly contrasted against phyletic gradualism, the idea that evolution generally occurs uniformly and by the steady, in this view, evolution is seen as generally smooth and continuous. In 1972, paleontologists Niles Eldredge and Stephen Jay Gould published a landmark paper developing their theory and their paper built upon Ernst Mayrs model of geographic speciation, I. Michael Lerners theories of developmental and genetic homeostasis, as well as their own empirical research, Punctuated equilibrium originated as a logical extension of Ernst Mayrs concept of genetic revolutions by allopatric and especially peripatric speciation as applied to the fossil record. The Eldredge and Gould paper was presented at the Annual Meeting of the Geological Society of America in 1971, the symposium focused its attention on the possibility that modern microevolutionary studies could revitalize various aspects of paleontology and macroevolution. Tom Schopf, who organized that years meeting, assigned Gould the topic of speciation, according to Gould the ideas came mostly from Niles, with yours truly acting as a sounding board and eventual scribe. I coined the term punctuated equilibrium and wrote most of our 1972 paper, in his book Time Frames Eldredge recalls that after much discussion the pair each wrote roughly half. Some of the parts that would seem obviously the work of one of us were actually first penned by the other—I remember for example, other parts are harder to reconstruct. Gould edited the manuscript for better consistency. We sent it in, and Schopf reacted strongly against it—thus signaling the tenor of the reaction it has engendered, though for shifting reasons, john Wilkins and Gareth Nelson have argued that French architect Pierre Trémaux proposed an anticipation of the theory of punctuated equilibrium of Gould and Eldredge. Graphically, these species are represented by horizontal lines, whose lengths depict how long each of them existed. The horizontality of the lines illustrates the unchanging appearance of each of the species depicted on the graph. During each species existence new species appear at intervals, each also lasting many hundreds of thousands of years before disappearing without a change in appearance. The degree of relatedness and the lines of descent of these concurrent species is generally impossible to determine, when Eldredge and Gould published their 1972 paper, allopatric speciation was considered the standard model of speciation. This model was popularized by Ernst Mayr in his 1954 paper Change of genetic environment and evolution, allopatric speciation suggests that species with large central populations are stabilized by their large volume and the process of gene flow. New and even beneficial mutations are diluted by the large size and are unable to reach fixation. If this is the case, then the transformation of whole lineages should be rare, smaller populations on the other hand, which are isolated from the parental stock, are decoupled from the homogenizing effects of gene flow
20.
Speciation
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Speciation is the evolutionary process by which biological populations evolve to become distinct species. The biologist Orator F. Cook coined the term speciation in 1906 for the splitting of lineages or cladogenesis, Charles Darwin was the first to describe the role of natural selection in speciation in his 1859 book The Origin of Species. He also identified sexual selection as a mechanism, but found it problematic. There are four modes of speciation in nature, based on the extent to which speciating populations are isolated from one another, allopatric, peripatric, parapatric. Speciation may also be induced artificially, through animal husbandry, agriculture, whether genetic drift is a minor or major contributor to speciation is the subject matter of much ongoing discussion. All forms of speciation have taken place over the course of evolution, however. During allopatric speciation, a population splits into two isolated populations. When the populations come back into contact, they have evolved such that they are isolated and are no longer capable of exchanging genes. Island genetics is the associated with the tendency of small. Examples include insular dwarfism and the changes among certain famous island chains. The Galápagos Islands are particularly famous for their influence on Charles Darwin, though the finches were less important for Darwin, more recent research has shown the birds now known as Darwins finches to be a classic case of adaptive evolutionary radiation. In peripatric speciation, a subform of allopatric speciation, new species are formed in isolated and it is related to the concept of a founder effect, since small populations often undergo bottlenecks. Genetic drift is often proposed to play a significant role in peripatric speciation, parapatric speciation may be associated with differential landscape-dependent selection. Even if there is a gene flow between two populations, strong differential selection may impede assimilation and different species may eventually develop, habitat differences may be more important in the development of reproductive isolation than the isolation time. Ecologists refer to parapatric and peripatric speciation in terms of ecological niches, a niche must be available in order for a new species to be successful. Ring species such as Larus gulls have been claimed to illustrate speciation in progress, the grass Anthoxanthum odoratum may be starting parapatric speciation in areas of mine contamination. Sympatric speciation refers to the formation of two or more descendant species from an ancestral species all occupying the same geographic location. Often-cited examples of sympatric speciation are found in insects that become dependent on different host plants in the same area, however, the existence of sympatric speciation as a mechanism of speciation remains highly debated
21.
International Standard Book Number
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The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, however, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces. Separating the parts of a 10-digit ISBN is also done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker
22.
Birding World
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Birding World was a monthly birding magazine published in the United Kingdom. It is the magazine of the Bird Information Service, based at Cley next the Sea, with the publication of issue No. 26/12 in January 2014, Birding World magazine ceased publication, originally published in 1987 as Twitching volume 1, the magazine underwent a name-change, to its present name,1988. The editor is Steve Gantlett, and the assistant editor Richard Millington and it is aimed at birders with an interest in the occurrence and identification of rare birds in the United Kingdom and the Western Palearctic. It also covers birding-related material from around the globe, list of journals and magazines relating to birding and ornithology Birding World Britains First Lesser Scaup article from Twitching, vol.1 issue 3 at the Wayback Machine
23.
Class (biology)
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In biological classification, class is, a taxonomic rank. Other well-known ranks in descending order of size are life, domain, kingdom, phylum, order, family, genus, as for the other well-known ranks, there is the option of an immediately lower rank, indicated by the prefix sub-, subclass. A taxonomic unit, a taxon, in that rank, in that case the plural is classes The composition of each class is determined by a taxonomist. Often there is no agreement, with different taxonomists taking different positions. There are no rules that a taxonomist needs to follow in describing a class. For example, dogs are assigned to the phylum Chordata, in the class Mammalia. In botany, classes are now rarely discussed, for some clades, a number of alternative classifications are used. In the first edition of his Systema Naturae, carl Linnaeus divided all three of his kingdoms of Nature into classes. The class was considered the highest level of the hierarchy until George Cuviers embranchements. Cladistics List of animal classes Phylogenetics Systematics Taxonomy
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Anatomy
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Anatomy is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is inherently tied to embryology, comparative anatomy, evolutionary biology, Human anatomy is one of the basic essential sciences of medicine. The discipline of anatomy is divided into macroscopic and microscopic anatomy, macroscopic anatomy, or gross anatomy, is the examination of an animals body parts using unaided eyesight. Gross anatomy also includes the branch of superficial anatomy, microscopic anatomy involves the use of optical instruments in the study of the tissues of various structures, known as histology, and also in the study of cells. The history of anatomy is characterized by an understanding of the functions of the organs. Anatomy and physiology, which study the structure and function of organisms and their parts, make a pair of related disciplines. Derived from the Greek ἀνατομή anatomē dissection, anatomy is the study of the structure of organisms including their systems, organs. It includes the appearance and position of the parts, the materials from which they are composed, their locations. Anatomy is quite distinct from physiology and biochemistry, which deal respectively with the functions of those parts, the discipline of anatomy can be subdivided into a number of branches including gross or macroscopic anatomy and microscopic anatomy. Gross anatomy is the study of large enough to be seen with the naked eye, and also includes superficial anatomy or surface anatomy. Microscopic anatomy is the study of structures on a scale, including histology. Anatomy can be studied using both invasive and non-invasive methods with the goal of obtaining information about the structure and organization of organs, angiography using X-rays or magnetic resonance angiography are methods to visualize blood vessels. The term anatomy is commonly taken to refer to human anatomy, however, substantially the same structures and tissues are found throughout the rest of the animal kingdom and the term also includes the anatomy of other animals. The term zootomy is also used to specifically refer to animals. The structure and tissues of plants are of a dissimilar nature, the kingdom Animalia or metazoa, contains multicellular organisms that are heterotrophic and motile. Most animals have bodies differentiated into separate tissues and these animals are known as eumetazoans. They have a digestive chamber, with one or two openings, the gametes are produced in multicellular sex organs, and the zygotes include a blastula stage in their embryonic development. Metazoans do not include the sponges, which have undifferentiated cells, unlike plant cells, animal cells have neither a cell wall nor chloroplasts
25.
Bird anatomy
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Bird anatomy, or the physiological structure of birds bodies, shows many unique adaptations, mostly aiding flight. The development of a beak has led to evolution of a specially adapted digestive system and these anatomical specializations have earned birds their own class in the vertebrate phylum. The bird skeleton is highly adapted for flight and it is extremely lightweight but strong enough to withstand the stresses of taking off, flying, and landing. One key adaptation is the fusing of bones into single ossifications, because of this, birds usually have a smaller number of bones than other terrestrial vertebrates. Birds also lack teeth or even a true jaw, instead having a beak, the beaks of many baby birds have a projection called an egg tooth, which facilitates their exit from the amniotic egg, and that falls off once it has done its job. Birds have many bones that are hollow with criss-crossing struts or trusses for structural strength, the number of hollow bones varies among species, though large gliding and soaring birds tend to have the most. Respiratory air sacs often form air pockets within the bones of the birds skeleton. The bones of diving birds are often less hollow than those of non-diving species, loons and puffins are without pneumatized bones entirely. Flightless birds, such as ostriches and emus, demonstrate osseous pneumaticity, possessing pneumatized femurs and, in the case of the emu, Birds also have more cervical vertebrae than many other animals, most have a highly flexible neck consisting of 13-25 vertebrae. Birds are the vertebrates to have fused clavicles or a keeled sternum or breastbone. The keel of the sternum serves as an attachment site for the used for flight or, similarly, for swimming. Again, flightless birds, such as ostriches, which do not have developed pectoral muscles. Swimming birds have a sternum, while walking birds have a long or high sternum and flying birds have a sternum width. Birds have uncinate processes on the ribs and these are hooked extensions of bone which help to strengthen the rib cage by overlapping with the rib behind them. This feature is found in the tuatara. They also have a greatly elongate tetradiate pelvis, similar to some reptiles, the hind limb has an intra-tarsal joint found also in some reptiles. There is extensive fusion of the vertebrae as well as fusion with the pectoral girdle. They have a skull, as in reptiles, with a pre-lachrymal fossa
26.
Bird flight
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Flight is the main mode of locomotion used by most of the worlds bird species. Flight assists birds while feeding, breeding, avoiding predators, and this article discusses the mechanics of bird flight, with emphasis on the varied forms of birds wings. The specifics of hovering, take-off and landing are also examined, additional adaptations of birds bodies relating to their flying ability are covered. Finally, theories on the evolution of flight are discussed. The fundamentals of flight are similar to those of aircraft, in which the aerodynamic forces sustaining flight are lift. Lift force is produced by the action of air flow on the wing, the airfoil is shaped such that the air provides a net upward force on the wing, while the movement of air is directed downward. Additional net lift may come from airflow around the body in some species. Aerodynamic drag is the force opposite to the direction of motion, the streamlining of birds body and wings reduces these forces. Flapping involves two stages, the down-stroke, which provides the majority of the thrust, and the up-stroke, at each up-stroke the wing is slightly folded inwards to reduce the energetic cost of flapping-wing flight. Birds change the angle of attack continuously within a flap, as well as with speed, when in gliding flight, the upward aerodynamic force on both birds and gliders is equal to the weight. The birds forelimbs are the key to flight, each wing has a central vane to hit the wind, composed of three limb bones, the humerus, ulna and radius. The other set of feathers, behind the carpal joint on the ulna, are called the secondaries. The remaining feathers on the wing are known as coverts, of which there are three sets, the wing sometimes has vestigial claws. Albatrosses have locking mechanisms in the joints that reduce the strain on the muscles during soaring flight. Female birds exposed to predators during ovulation produce chicks that grow their wings faster than chicks produced by predator-free females, both adaptations may make them better at avoiding avian predators. The shape of the wing is important in determining the capabilities of a bird. Different shapes correspond to different trade-offs between advantages such as speed, low use, and maneuverability. Two important parameters are the ratio and wing loading
27.
Egg
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An egg is the organic vessel containing the zygote in which an animal embryo develops until it can survive on its own, at which point the animal hatches. An egg results from fertilization of an ovum, most arthropods, vertebrates, and mollusks lay eggs, although some do not, such as scorpions and most mammals. Reptile eggs, bird eggs, and monotreme eggs are laid out of water, eggs laid on land or in nests are usually kept within a favorable temperature range while the embryo grows. When the embryo is developed it hatches, i. e. breaks out of the eggs shell. Some embryos have an egg tooth with which to crack, pip. The largest recorded egg is from a shark, and was 30 cm ×14 cm ×9 cm in size. At 1.5 kg and up to 17.8 cm ×14 cm, the bee hummingbird produces the smallest known bird egg, which weighs half of a gram. The eggs laid by some reptiles and most fish can be smaller. Reproductive structures similar to the egg in other kingdoms are termed spores, or in spermatophytes seeds, several major groups of animals typically have readily distinguishable eggs. The most common strategy for fish is known as oviparity. Typically large numbers of eggs are laid at one time and the eggs are left to develop without parental care. When the larvae hatch from the egg, they carry the remains of the yolk in a yolk sac which continues to nourish the larvae for a few days as they learn how to swim. Once the yolk is consumed, there is a point after which they must learn how to hunt. A few fish, notably the rays and most sharks use ovoviviparity in which the eggs are fertilized, however the larvae still grow inside the egg consuming the eggs yolk and without any direct nourishment from the mother. The mother then gives birth to relatively mature young, in certain instances, the physically most developed offspring will devour its smaller siblings for further nutrition while still within the mothers body. This is known as intrauterine cannibalism, the eggs of fish and amphibians are jellylike. Cartilagenous fish eggs are fertilized internally and exhibit a variety of both internal and external embryonic development. Most fish species spawn eggs that are fertilized externally, typically with the male inseminating the eggs after the female lays them and these eggs do not have a shell and would dry out in the air
28.
Feather
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Feathers are epidermal growths that form the distinctive outer covering, or plumage, on birds. They are considered the most complex integumentary structures found in vertebrates and they are among the characteristics that distinguish the extant birds from other living groups. Although feathers cover most parts of the body of birds, they arise only from certain well-defined tracts on the skin and they aid in flight, thermal insulation, and waterproofing. In addition, coloration helps in communication and protection, plumology is the name for the science that is associated with the study of feathers. Feathers are among the most complex integumentary appendages found in vertebrates and are formed in tiny follicles in the epidermis, or outer skin layer, that produce keratin proteins. There are two types of feather, vaned feathers which cover the exterior of the body. The pennaceous feathers are vaned feathers, also called contour feathers, pennaceous feathers arise from tracts and cover the entire body. In some passerines, filoplumes arise exposed beyond the contour feathers on the neck, the remiges, or flight feathers of the wing, and rectrices, the flight feathers of the tail are the most important feathers for flight. A typical vaned feather features a main shaft, called the rachis, fused to the rachis are a series of branches, or barbs, the barbs themselves are also branched and form the barbules. These barbules have minute hooks called barbicels for cross-attachment, down feathers are fluffy because they lack barbicels, so the barbules float free of each other, allowing the down to trap air and provide excellent thermal insulation. At the base of the feather, the rachis expands to form the hollow tubular calamus which inserts into a follicle in the skin, the basal part of the calamus is without vanes. This part is embedded within the follicle and has an opening at the base. Hatchling birds of species have a special kind of natal down feathers which are pushed out when the normal feathers emerge. Flight feathers are stiffened so as to work against the air in the downstroke, feathers insulate birds from water and cold temperatures. They may also be plucked to line the nest and provide insulation to the eggs, the individual feathers in the wings and tail play important roles in controlling flight. Some species have a crest of feathers on their heads, although feathers are light, a birds plumage weighs two or three times more than its skeleton, since many bones are hollow and contain air sacs. Color patterns serve as camouflage against predators for birds in their habitats, as with fish, the top and bottom colors may be different, in order to provide camouflage during flight. Striking differences in patterns and colors are part of the sexual dimorphism of many bird species and are particularly important in selection of mating pairs
29.
Plumage
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Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies, and may vary with age classes, within species there can be different colour morphs. The placement of feathers on a bird are not haphazzard, but rather emerge in organized, overlapping rows and groups, most birds moult, usually before and after breeding, resulting in a breeding or nuptial plumage and a basic plumage. Many ducks and some species such as the red junglefowl have males wearing a bright nuptial plumage while breeding. The painted buntings juveniles have two inserted moults in their first autumn, each yielding plumage like an adult females, the first starts a few days after fledging replacing the juvenile plumage with an auxiliary formative plumage, the second a month or so later giving the formative plumage. Abnormal plumages include a variety of conditions, albinism, total loss of colour, is rare, but partial loss of colours is more common. Some species are polymorphic, having two or more colour variants. A few species have special types of polymorphism, as in the male ruff which has an assortment of different colours around the head, hen feathering is an inherited plumage character in domestic fowl controlled by a single gene. Plumology is the name for the science that is associated with the study of feathers, almost all species of birds moult at least annually, usually after the breeding season, known as the pre-basic moult. This resulting covering of feathers, which will last either until the breeding season or until the next annual moult, is known as the basic plumage. Many species undertake another moult prior to the season known as the pre-alternate moult. The alternate plumage is brighter than the basic plumage, for the purposes of sexual display. The Humphrey-Parkes terminology requires some attention to detail to name moults, many ducks have bright, colourful plumage, exhibiting strong sexual dimorphism. However, they moult into a dull plumage after breeding in mid-summer and this drab, female-like appearance is called eclipse plumage. When they shed feathers to go into eclipse, the ducks become flightless for a period of time. Although mainly found in the Anatidae, a few species, including related red junglefowl, most fairywrens. There are hereditary as well as variations in plumage that are rare. Melanism refers to an excess of black or dark colours, erythromelanism or erythrism is the result of excessive reddish brown erythromelanin deposition in feathers that normally lack melanin
30.
Bird vision
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The avian eye resembles that of a reptile, with ciliary muscles that can change the shape of the lens rapidly and to a greater extent than in the mammals. Birds have the largest eyes relative to their size in the animal kingdom, in addition to the two eyelids usually found in vertebrates, it is protected by a third transparent movable membrane. The eyes internal anatomy is similar to that of vertebrates, but has a structure. Some bird groups have specific modifications to their visual system linked to their way of life, Birds of prey have a very high density of receptors and other adaptations that maximise visual acuity. The placement of their eyes gives them good binocular vision enabling accurate judgement of distances, nocturnal species have tubular eyes, low numbers of colour detectors, but a high density of rod cells which function well in poor light. Terns, gulls and albatrosses are amongst the seabirds which have red or yellow oil droplets in the receptors to improve distance vision especially in hazy conditions. The eye of a bird most closely resembles that of the reptiles, unlike the mammalian eye, it is not spherical, and the flatter shape enables more of its visual field to be in focus. Most birds cannot move their eyes, although there are exceptions, the American woodcock probably has the largest visual field of any bird, 360° in the horizontal plane, and 180° in the vertical plane. The eyelids of a bird are not used in blinking, instead the eye is lubricated by the nictitating membrane, a third concealed eyelid that sweeps horizontally across the eye like a windscreen wiper. The nictitating membrane also covers the eye and acts as a lens in many aquatic birds when they are under water. When sleeping, the lower eyelid rises to cover the eye in most birds, the eye is also cleaned by tear secretions from the lachrymal gland and protected by an oily substance from the Harderian glands which coats the cornea and prevents dryness. The eye of a bird is larger compared to the size of the animal than for any group of animals. The ostrich has the largest eye of any vertebrate, with an axial length of 50 mm. Bird eye size is related to body mass. A study of five orders showed that eye mass is proportional to body mass, for a pigeon, resolution is twice as good with sideways monocular vision than forward binocular vision, whereas for humans the converse is true. Although many species migrate at night, they collide with even brightly lit objects like lighthouses or oil platforms. Birds of prey are diurnal because, although their eyes are large, they are optimised to give maximum spatial resolution rather than light gathering, so they also do not function well in poor light. Many birds have an asymmetry in the structure which enables them to keep the horizon
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Dactyly
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In biology, dactyly is the arrangement of digits on the hands, feet, or sometimes wings of a tetrapod animal. It comes from the Greek word δακτυλος = finger, sometimes the ending -dactylia is used. The derived adjectives end with -dactyl or -dactylous, pentadactyly is the condition of having five digits on each limb. However, this viewpoint was challenged by Stephen Jay Gould in his 1991 essay Eight Little Piggies, despite the individual variations listed below, the relationship is to the original five-digit model. In reptiles, the limbs are pentadactylous, tetradactyly is the condition of having four digits on a limb, as in many amphibians, birds, and theropod dinosaurs. Cartoon characters are drawn with four digits on each hand/foot as its clearer to see than five. Tridactyly is the condition of having three digits on a limb, as in the rhinoceros and ancestors of the such as Protohippus. These all belong to the Perissodactyla, some birds also have three toes, including emus, bustards, and quail. Didactyly or bidactyly is the condition of having two digits on each limb, as in the Hypertragulidae and two-toed sloth, Choloepus didactylus. In humans this name is used for an abnormality in which the digits are missing, leaving only the thumb and fifth finger, or big. Cloven-hoofed mammals have two digits, as do ostriches. Monodactyly is the condition of having a single digit on a limb, syndactyly is a condition where two or more digits are fused together. It occurs normally in some mammals, such as the siamang and it occurs as an unusual condition in humans. Polydactyly is when a limb has more than the number of digits. This can be, As a result of abnormality in a normally pentadactyl animal. Polydactyly is very common among domestic cats and it also occurs secondarily in some later tetrapods, such as ichthyosaurs. Oligodactyly is having too few digits when not caused by an amputation and it is sometimes incorrectly called hypodactyly or confused with aphalangia, the absence of the phalanx bone on one or more digits. When all the digits on a hand or foot are absent, ectrodactyly, also known as split-hand malformation, is the congenital absence of one or more central digits of the hands and feet
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Uropygial gland
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The uropygial gland, informally known as the preen gland or the oil gland, is a bilobate sebaceous gland possessed by the majority of birds. It is located dorsally at the base of the tail and is variable in both shape and size. In some species, the opening of the gland has a tuft of feathers to provide a wick for the preen oil. Each lobe has a cavity that collects the secretion from tubules arranged radially around the cavity. The gland secretion is conveyed to the surface via ducts that, in most species, from uropygium, Mediaeval Latin, from Ancient Greek οὐροπύγιον, from οὐρά tail and πυγή rump. The gland is present at embryonic stages, whereas it can be vestigial in adults of certain orders, families, genera. Some or all species in at least nine families of birds lack a uropygial gland and these include kiwis, emu, ostriches, rheas, cassowaries, mesites, bustards, pigeons and doves, amazon parrots, frogmouths, and woodpeckers. These birds typically find other means to clean and dry. Researchers have been unable to correlate the presence or absence of the gland with factors such as distribution, climate, ecology. The uropygial gland secretes an oil through the surface of the skin via a grease nipple-like nub or papilla. The oil contains a complex and variable mixture of substances formed greatly of aliphatic monoester waxes, formed of fatty acids, however, some types of diester waxes called uropygiols and containing hydroxyfatty acids and/or alkane-diols exist in the secretions of the uropygial gland of some groups of birds. Tailward areas are usually preened utilizing the beak, although some species, emperor Frederick II, in his thirteenth-century treatise on falconry, was seemingly the first to discuss the function of the uropygial gland of birds. He believed that its not only oiled the plumage but also provided a poison which was introduced by the claws of hawks. However, studies in 1678 on the question of the nature of the uropygial gland secretion found no evidence to support Fredericks contention. Several researchers have reported differences in the relative gland weights attributing them to factors like seasonal changes, habitat, body weight, inter-individual variations, and sex. Significant differences are found in the gland size between males and females in most species, however, no coherent explanation has as yet been found for these results. Many ornithologists believe the function of the uropygial gland differs among species of birds. The preen oil is believed to maintain the integrity of the feather structure
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Bird vocalization
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Bird vocalization includes both bird calls and bird songs. In non-technical use, bird songs are the sounds that are melodious to the human ear. In ornithology and birding, songs are distinguished by function from calls, the distinction between songs and calls is based upon complexity, length, and context. Songs are longer and more complex and are associated with courtship and mating, still others require song to have syllabic diversity and temporal regularity akin to the repetitive and transformative patterns that define music. It is generally agreed upon in birding and ornithology which sounds are songs and which are calls, Bird song is best developed in the order Passeriformes. Some groups are nearly voiceless, producing only percussive and rhythmic sounds, such as the storks, in some manakins, the males have evolved several mechanisms for mechanical sound production, including mechanisms for stridulation not unlike those found in some insects. Song is usually delivered from prominent perches, although some species may sing when flying, the production of sounds by mechanical means as opposed to the use of the syrinx has been termed variously instrumental music by Charles Darwin, mechanical sounds and more recently sonation. With aseasonal irregular breeding, both sexes must be brought into breeding condition and vocalisation, especially duetting, serves this purpose, the high frequency of female vocalisations in the tropics, Australia and Southern Africa may also relate to very low mortality rates producing much stronger pair-bonding and territoriality. The avian vocal organ is called the syrinx, it is a structure at the bottom of the trachea. The syrinx and sometimes a surrounding air sac resonate to sound waves that are made by membranes past which the bird forces air, the bird controls the pitch by changing the tension on the membranes and controls both pitch and volume by changing the force of exhalation. It can control the two sides of the trachea independently, which is how some species can produce two notes at once, scientists hypothesize that bird song has evolved through sexual selection, and experiments suggest that the quality of bird song may be a good indicator of fitness. Experiments also suggest that parasites and diseases may directly affect song characteristics such as song rate, the song repertoire also appears to indicate fitness in some species. The ability of birds to hold and advertise territories using song also demonstrates their fitness. Communication through bird calls can be individuals of the same species or even across species. Mobbing calls are used to recruit individuals in an area where an owl or other predator may be present, the alarm calls of most species, on the other hand, are characteristically high-pitched, making the caller difficult to locate. Individual birds may be enough to identify each other through their calls. Many birds that nest in colonies can locate their chicks using their calls, calls are sometimes distinctive enough for individual identification even by human researchers in ecological studies. Many birds engage in duet calls, in some cases, the duets are so perfectly timed as to appear almost as one call
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Bird intelligence
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Bird intelligence deals with the definition of intelligence and its measurement as it applies to birds. Traditionally, birds have been considered inferior in intelligence to humans and still are, the difficulty of defining or measuring intelligence in non-human animals makes the subject difficult for scientific study. Anatomically, a bird has a large brain compared to its head size. The visual and auditory senses are well developed in most species, while the tactile, Birds communicate using visual signals as well as through the use of calls and song. The testing of intelligence is based on studying the responses to sensory stimuli. Bird intelligence has been studied through several attributes and abilities, many of these studies have been on birds such as quail, domestic fowl and pigeons kept under captive conditions. It has, however, been noted that studies have been limited. Counting has been considered an ability that shows intelligence, anecdotal evidence from the 60s has suggested that crows may count up to 3. Researchers however need to be cautious and ensure that birds are not merely demonstrating the ability to subitize, some studies, such as one done at Moscow State University, have suggested that crows may indeed have a true numerical ability. It has been shown that parrots can count up to 6, cormorants used by Chinese fishermen that were given every eighth fish as a reward were found to be able to keep count up to seven. Hoh wrote in Natural History magazine, In the 1970s, on the Li River, Pamela Egremont observed fishermen who allowed the birds to eat every eighth fish they caught. Writing in the Biological Journal of the Linnean Society, she reported that, once their quota of seven fish was filled and they ignore an order to dive and even resist a rough push or a knock, sitting glum and motionless on their perches. Meanwhile, other birds that had not filled their quotas continued to fish as usual. One is forced to conclude that these intelligent birds can count up to seven. Many birds are able to detect changes in the number of eggs in their nest. Parasitic cuckoos are known to remove one of the host eggs before laying their own. Also, A common test of intelligence is the detour test, most mammals discover that the objective is reached by first going away from the target. Whereas domestic fowl fail on this test, many within the family are able to readily solve the problem
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Bird migration
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Bird migration is the regular seasonal movement, often north and south along a flyway, between breeding and wintering grounds. Migration carries high costs in predation and mortality, including from hunting by humans and it occurs mainly in the northern hemisphere, where birds are funnelled on to specific routes by natural barriers such as the Mediterranean Sea or the Caribbean Sea. More recently, Johannes Leche began recording dates of arrivals of spring migrants in Finland in 1749, threats to migratory birds have grown with habitat destruction especially of stopover and wintering sites, as well as structures such as power lines and wind farms. The Arctic tern holds the long-distance migration record for birds, travelling between Arctic breeding grounds and the Antarctic each year, shorter migrations are common, including altitudinal migrations on mountains such as the Andes and Himalayas. The timing of migration seems to be controlled primarily by changes in day length, migrating birds navigate using celestial cues from the sun and stars, the earths magnetic field, and probably also mental maps. Records of bird migration were made as much as 3,000 years ago by the Ancient Greek writers Hesiod, Homer, Herodotus and Aristotle. The Bible also notes migrations, as in the Book of Job, the author of Jeremiah wrote, Even the stork in the heavens knows its seasons, and the turtle dove, the swift and the crane keep the time of their arrival. Aristotle noted that cranes traveled from the steppes of Scythia to marshes at the headwaters of the Nile, pliny the Elder, in his Historia Naturalis, repeats Aristotles observations. Aristotle however suggested that swallows and other birds hibernated and this belief persisted as late as 1878, when Elliott Coues listed the titles of no less than 182 papers dealing with the hibernation of swallows. It was not until the end of the century that migration as an explanation for the winter disappearance of birds from northern climes was accepted. Bewick then describes an experiment which succeeded in keeping alive in Britain for several years. He concludes, These experiments have since been confirmed by. Migration is the seasonal movement, often north and south. Bird movements include those made in response to changes in food availability, habitat, sometimes, journeys are not termed true migration because they are irregular or in only one direction. Migration is marked by its annual seasonality, non-migratory birds are said to be resident or sedentary. Approximately 1800 of the worlds 10,000 bird species are long-distance migrants, many bird populations migrate long distances along a flyway. The most common pattern involves flying north in the spring to breed in the temperate or Arctic summer, of course, in the southern hemisphere the directions are reversed, but there is less land area in the far south to support long-distance migration. The primary motivation for migration appears to be food, for example, also, the longer days of the northern summer provide extended time for breeding birds to feed their young
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Lek mating
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A lek is an aggregation of male animals gathered to engage in competitive displays, lekking, that may entice visiting females which are surveying prospective partners for copulation. Leks are commonly formed before or during the breeding season, a lekking species is characterised by male displays, strong female mate choice, and the conferring of male indirect benefits. Although lekking is most prevalent among avian species, lekking behavior also occurs in insects, amphibians, the term derives from the Swedish lek, a noun which typically denotes pleasurable and less rule-bound games and activities. English use of lek dates to the 1860s, llewelyn Lloyds The Game birds and wild fowl of Sweden and Norway introduces it explicitly as a Swedish term. Lekking is seen in mammals such as the Ugandan kob, some pinnipeds, several species of fruit bat. Lekking is found in such as moor frogs and bullfrogs, reptiles such as marine iguanas. Even insects like the midge and the ghost moth demonstrate lekking behavior, there are two types of lekking arrangements, classical and exploded. In the classic lekking system, male territories are in visual, in an exploded lek, males are further away from one another than they would be in a classic lek. Males in a lek are outside of visual range of one another. Exploded lek territories are more expansive than classic systems and are known to exhibit more variation. A well-known example of exploded leks is the call of the kakapo. Lek territories of different taxa are stable and do not vary in terms of size, males often return to the same mating sites because of female fidelity. It has been shown that avian females such as the black grouse and great snipe are faithful to males, successful males congregate in the same area as the previous breeding season because it is familiar to them, while females return to reunite with said males. Females do not return to a site if their male partner is not present. Another possible explanation for lek stability is from male hierarchies within a lek, in manakins, subordinate betas may inherit an alphas display site, increasing the chances of female visitation. Rank may also contribute to the stability of lek size, as lower ranking males may congregate to achieve an optimal size as a way to attract females. Some species of ants, such as red harvester ants, as well as certain bee species, like Tetragonisca angustula, males form reproductive aggregations, congregating and collectively give off a pheromone that attracts reproductive females. The more males present to give off the pheromone, the stronger the attraction for the females, lek mating is relatively common among paper wasp species
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Seabird breeding behavior
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The term seabird is used for many families of birds in several orders that spend the majority of their lives at sea. Seabirds make up some, if not all, of the families in the orders, Procellariiformes, Sphenisciformes, Pelecaniformes. Many seabirds remain at sea for several years at a time. Breeding is the purpose for seabirds to visit land. The breeding period is usually extremely protracted in many seabirds and may last over a year in some of the larger albatrosses, seabirds nest in single or mixed-species colonies of varying densities, mainly on offshore islands devoid of terrestrial predators. However, seabirds exhibit many unusual breeding behaviors during all stages of the cycle that are not extensively reported outside of the primary scientific literature. The courtship stage of breeding is when pair bonds are formed and occurs before copulation and occasionally continues through the copulatory and chick-rearing stages of the breeding phenology. The sequence and variety of courting behaviors vary widely among species, but they begin with territorial defense, followed by mate-attraction displays. Seabirds are long-lived, socially monogamous, birds that usually mate for life and this makes selecting a mate extremely important with lifelong implications for the reproductive success of both individuals in the pair. Seabirds are one of the only families that include ritualized dances in their courtship. These dances are complex and can include displays and vocalizations that vary greatly between families and orders, Albatrosses are well known for their intricate mating dances. All species of albatross have some form of ritualized dance, with many species displaying very similar forms, albatrosses’ complex visual and vocal dances are considered some of the most developed mating displays in any long-lived animal. Both members of the use these dances as a proxy for mate quality. For black-footed and Laysan albatrosses there are ten described parts to their dance which can be given in various sequences. Several parts include “billing” where one individual gently touches the others bill and “sky pointing” where the bird rises on the tips of its toes, stretches its neck, the mating dance may last for several minutes. Boobies are another group of known for their mating displays. Brown, red-footed and blue-footed boobies have at least nine described parts to their mating display, in blue-footed and red-footed boobies, parading also includes lifting and flaunting their brightly colored feet at their prospective partner. Frigatebirds are known for their displays and breeding system
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Egg incubation
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Incubation refers to the process by which certain oviparous animals hatch their eggs, it also refers to the development of the embryo within the egg. Multiple and various factors are vital to the incubation of various species of animal, in many species of reptile for example, no fixed temperature is necessary, but the actual temperature determines the sex ratio of the offspring. In birds in contrast, the genders of offspring are genetically determined, especially in poultry, the act of sitting on eggs to incubate them is called brooding. A wide range of incubation habits is displayed among birds, the Namaqua sandgrouse of the deserts of southern Africa, needing to keep its eggs cool during the heat of the day, stands over them drooping its wings to shade them. The humidity is also critical, because if the air is too dry the egg will lose too much water to the atmosphere, which can make hatching difficult or impossible. As incubation proceeds, an egg will normally become lighter, in the species that incubate, the work is divided differently between the sexes. Possibly the most common pattern is that the female all the incubation, as in the coscoroba swan. In some species, such as the crane, the male. In others, such as the cassowaries, only the male incubates, the male mountain plover incubates the females first clutch, but if she lays a second, she incubates it herself. In hoatzins, some birds help their parents incubate later broods, the incubation period, the time from the start of uninterrupted incubation to the emergence of the young, varies from 11 days to 85 days. In these latter, the incubation is interrupted, the longest uninterrupted period is 64 to 67 days in the emperor penguin, in general smaller birds tend to hatch faster, but there are exceptions, and cavity nesting birds tend to have longer incubation periods. It can be a demanding process, with adult albatrosses losing as much as 83 g of body weight a day. Megapode eggs take from 49 to 90 days depending on the mound, even in other birds, ambient temperatures can lead to variation in incubation period. Normally, of course, the egg is incubated outside the body, however, in one recorded case, the egg incubation occurred entirely within a chicken. The chick hatched inside and emerged from its mother without the shell, embryo development remains suspended until the onset of incubation. The freshly laid eggs of fowl, ostrich, and several other species can be stored for about two weeks when maintained under 5 C. Extended periods of suspension have been observed in marine birds. Some start to incubate after the last egg of the clutch, incubation periods for birds Very few mammals lay eggs
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Brood parasite
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Brood parasites are organisms that rely on others to raise their young. The strategy appears among birds, insects and some fish, the brood parasite manipulates a host, either of the same or of another species, to raise its young as if it were its own. Bird parasite species mitigate the risk of egg loss by distributing eggs amongst a number of different hosts, as this behaviour damages the host, it often results in an evolutionary arms race between parasite and host as the pair of species coevolve. This form of cuckoldry is taken a step further when females of the goldeneye often lay their eggs in the nests of other individuals, intraspecific brood parasitism is seen in a number of duck species, where females often lay their eggs in the nests of others. Interspecific brood-parasites include the indigobirds, whydahs, and honeyguides in Africa, cowbirds, Old World cuckoos, black-headed ducks, seven independent origins of obligate interspecific brood parasitism in birds have been proposed. They usually lay one egg per nest, although in some cases, particularly the cowbirds. Genes regulating egg coloration appear to be passed down exclusively along the maternal line, females generally parasitize nests of the species which raised them. Male common cuckoos fertilize females of all lines, which maintains sufficient gene flow among the different maternal lines to prevent speciation, the mechanisms of host selection by female cuckoos are somewhat unclear, though several hypotheses have been suggested in attempt to explain the choice. Of these hypotheses the nest-site selection and habitat selection have been most supported by experimental analysis, among specialist avian brood parasites, mimetic eggs are a nearly universal adaptation. There is even evidence that the generalist brown-headed cowbird may have evolved an egg coloration mimicking a number of their hosts. Most avian brood parasites remove a host egg when they lay one of their own in a nest, depending upon the species, this can happen either in the same visit to the host nest or in a separate visit before or after the parasitism. This both prevents the host species from realizing their nest has been parasitized and reduces competition for the parasitic nestling once it hatches, most avian brood parasites have very short egg incubation periods and rapid nestling growth. This gives the parasitic nestling a head start on growth over its nestmates, in many brood parasites, such as cuckoos and honeyguides, this short egg incubation period is due to internal incubation periods up to 24 hours longer in cuckoos than hosts. Where the host nestlings are significantly smaller than the parasite nestling, some brood parasites eliminate all their nestmates shortly after hatching, either by ejecting them from the nest or killing them with sharp mandible hooks which fall off after a few days. There is a question as to why the majority of the hosts of brood parasites care for the nestlings of their parasites. Not only do these parasites usually differ significantly in size and appearance. The mafia hypothesis evolved through studies in an attempt to answer this question and this hypothesis revolves around host manipulations induced by behaviors of the brood parasite. Upon the detection and rejection of a brood egg, the hosts nest is depredated upon, its nest destroyed
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Bird nest
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A bird nest is the spot in which a bird lays and incubates its eggs and raises its young. The smallest bird nests are those of hummingbirds, tiny cups which can be a mere 2 cm across. At the other extreme, some nest mounds built by the dusky scrubfowl measure more than 11 m in diameter, not all bird species build nests. Most birds build a new nest each year, though some refurbish their old nests, the large eyries of some eagles are platform nests that have been used and refurbished for several years. In most species, the female does most or all of the nest construction, in some polygynous species, however, the male does most or all of the nest building. The nest may also form a part of the display such as in weaver birds. The ability to choose and maintain good nest sites and build high quality nests may be selected for by females in these species, in some species the young from previous broods may also act as helpers for the adults. Not every bird species builds or uses a nest, some auks, for instance—including common murre, thick-billed murre and razorbill—lay their eggs directly onto the narrow rocky ledges they use as breeding sites. The eggs of species are dramatically pointed at one end. This is critical for the survival of the eggs, as there are no nests to keep them from rolling off the side of the cliff. Presumably because of the vulnerability of their eggs, parent birds of these auk species rarely leave them unattended. Nest location and architecture is influenced by local topography and other abiotic factors. King penguins and emperor penguins also do not build nests, instead, they tuck their eggs and they are thus able to move about while incubating, though in practice only the emperor penguin regularly does so. Without the ability to body heat, the penguins would expend far more energy trying to stay warm. Potoos lay their single egg directly atop a broken stump, or into a depression on a branch—typically where an upward-pointing branch died and fell off. Brood parasites, such as the New World cowbirds, the honeyguides, the simplest nest construction is the scrape, which is merely a shallow depression in soil or vegetation. This nest type, which typically has a rim deep enough to keep the eggs from rolling away, is lined with bits of vegetation, small stones. Ostriches, most tinamous, many ducks, most shorebirds, most terns, some falcons, pheasants, quail, partridges, bustards, brooding adults also tend to be well camouflaged, and may be difficult to flush from the nest
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Evolution
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Evolution is change in the heritable characteristics of biological populations over successive generations. Evolutionary processes give rise to biodiversity at every level of organisation, including the levels of species, individual organisms. In July 2016, scientists reported identifying a set of 355 genes from the LUCA of all living on Earth. The fossil record includes a progression from early biogenic graphite, to microbial mat fossils, existing patterns of biodiversity have been shaped both by speciation and by extinction. More than 99 percent of all species that lived on Earth are estimated to be extinct. Estimates of Earths current species range from 10 to 14 million, more recently, in May 2016, scientists reported that 1 trillion species are estimated to be on Earth currently with only one-thousandth of one percent described. In the mid-19th century, Charles Darwin formulated the theory of evolution by natural selection. This teleonomy is the quality whereby the process of natural selection creates and preserves traits that are fitted for the functional roles they perform. The processes by which the changes occur, from one generation to another, are called evolutionary processes or mechanisms, the four most widely recognized evolutionary processes are natural selection, genetic drift, mutation and gene migration. Natural selection and genetic drift sort variation, mutation and gene migration create variation, consequences of selection can include meiotic drive, nonrandom mating and genetic hitchhiking. In the early 20th century the modern evolutionary synthesis integrated classical genetics with Darwins theory of evolution by natural selection through the discipline of population genetics, the importance of natural selection as a cause of evolution was accepted into other branches of biology. Moreover, previously held notions about evolution, such as orthogenesis, evolutionism, evolutionary computation, a sub-field of artificial intelligence, involves the application of Darwinian principles to problems in computer science. The proposal that one type of organism could descend from another type goes back to some of the first pre-Socratic Greek philosophers, such as Anaximander, such proposals survived into Roman times. The poet and philosopher Lucretius followed Empedocles in his masterwork De rerum natura, in contrast to these materialistic views, Aristotelianism considered all natural things as actualisations of fixed natural possibilities, known as forms. This was part of a teleological understanding of nature in which all things have an intended role to play in a divine cosmic order. In the 17th century, the new method of modern science rejected the Aristotelian approach, however, this new approach was slow to take root in the biological sciences, the last bastion of the concept of fixed natural types. The biological classification introduced by Carl Linnaeus in 1735 explicitly recognized the nature of species relationships. Other naturalists of this time speculated on the change of species over time according to natural laws
