1.
Female
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Female is the sex of an organism, or a part of an organism, that produces non-mobile ova. Most female mammals, including humans, have two X chromosomes. The ova are defined as the larger gametes in a heterogamous reproduction system, while the smaller, usually motile gamete, a female individual cannot reproduce sexually without access to the gametes of a male. Some organisms can reproduce sexually and asexually. There is no single genetic mechanism behind sex differences in different species, oogamy is a form of anisogamy. There is an argument that this pattern was driven by the constraints on the mechanisms by which two gametes get together as required for sexual reproduction. Other than the difference in the type of gamete produced. The concept is not limited to animals, egg cells are produced by chytrids, diatoms, water moulds and land plants, among others. In land plants, female and male designate not only the egg- and sperm-producing organisms and structures, the word female comes from the Latin femella, the diminutive form of femina, meaning woman. It is not etymologically related to the male, but in the late 14th century the spelling was altered in English to parallel the spelling of male. A distinguishing characteristic of the class Mammalia is the presence of mammary glands, the mammary glands are modified sweat glands that produce milk, which is used to feed the young for some time after birth. Mammary glands are most obvious in humans, as the human body stores large amounts of fatty tissue near the nipples. Mammary glands are present in all mammals, although they are vestigial in the male of the species, most mammalian females have two copies of the X chromosome as opposed to the male which carries only one X and one smaller Y chromosome. To compensate for the difference in size, one of the females X chromosomes is inactivated in each cell of placental mammals while the paternally derived X is inactivated in marsupials. In birds and some reptiles, by contrast, it is the female which is heterozygous and carries a Z and a W chromosome whilst the male carries two Z chromosomes. Intersex conditions can give rise to other combinations, such as XO or XXX in mammals. However, these conditions result in sterility. A common symbol used to represent the female sex is ♀, according to Schott, the most established view is that the male and female symbols are derived from contractions in Greek script of the Greek names of these planets, namely Thouros and Phosphoros
2.
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
3.
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
4.
Clutch (eggs)
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A clutch of eggs refers to all the eggs produced by birds, amphibians, or reptiles, often at a single time, particularly those laid in a nest. In birds, destruction of a clutch by predators results in double-clutching, the technique is used to double the production of a species eggs, in the California condor case, specifically to increase population size. The act of putting ones hand in a nest to remove eggs is known as dipping the clutch, clutch size differs greatly between species, sometimes even within the same genus. It may also differ within the species due to many factors including habitat, health, nutrition, predation pressures. Clutch size variation can also reflect variation in optimal reproduction effort, in birds, clutch size can vary within a species due to various features, while some species are determinant layers, laying a species-specific number of eggs. Long-lived species tend to have smaller clutch sizes than short-lived species, the evolution of optimal clutch size is also driven by other factors, such as parent-offspring conflict. Clutch size recorded in field notes may or may not include lost or broken eggs
5.
Condor
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Condor is the common name for two species of New World vultures, each in a monotypic genus. The name derives from the Quechua kuntur and they are the largest flying land birds in the Western Hemisphere. They are, The Andean condor which inhabits the Andean mountains, the California condor currently restricted to the western coastal mountains of the United States and Mexico and the northern desert mountains of Arizona in the United States. Condors are part of the family Cathartidae, whereas the 15 species of Old World vultures are in the family Accipitridae, that includes hawks, eagles. The New World and Old World vultures evolved from different ancestors, however, they both are carrion-eaters and have distinctive bare heads. Both condors are very large broad-winged soaring birds, the Andean condor being 5 cm shorter on average than the northern species, California condors are the largest flying land birds in North America. The Andean condor is second only to the albatross in terms of wingspan among all living flying birds. The adult plumage is black, with the exception of a frill of white feathers nearly surrounding the base of the neck which are meticulously kept clean by the bird. As an adaptation for hygiene, the head and neck have few feathers. The head is flattened above. In the male it is crowned with a caruncle or comb, while the skin of the neck in the lies in folds. The skin of the head and neck is capable of flushing noticeably in response to emotional state, the middle toe is greatly elongated, and the hinder one but slightly developed, while the talons of all the toes are comparatively straight and blunt. The feet are more adapted to walking as in their relatives the storks. The female, contrary to the rule among birds of prey, is smaller than the male.5 to 11 kg for females. Overall length can range from 117 to 135 cm Measurements are usually taken from specimens reared in captivity, California condors wingspan measures up to 2.9 m, and they can weigh up to 10.4 kg. The skin on the necks will vary in color, depending on the age of the birds, adult birds skin color can range from cream, pink, yellow, or even orange during breeding season. Some scientists also believe that an ancient relative of the condor, Argentavis magnificens from South America, sexual maturity and breeding behavior do not appear in the condor until 5 or 6 years of age. They may live for 50 years or more, and mate for life, the worlds oldest condor died at 100 in the Jardin dEssai du Hamma in Algiers
6.
Grey partridge
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The grey partridge, also known as the English partridge, Hungarian partridge, or hun, is a gamebird in the pheasant family Phasianidae of the order Galliformes, gallinaceous birds. The scientific name is the Latin for partridge, and is derived from Ancient Greek perdix. Widespread and common throughout much of its range, the partridge is evaluated as of Least Concern on the IUCN Red List of Threatened Species. However, it has suffered a decline in the UK. This partridge breeds on farmland across most of Europe into western Asia, a popular gamebird in vast areas of North America, it is commonly known as Hungarian partridge or just hun. The grey partridge is a bird, 28–32 cm long, brown-backed, with grey flanks. The belly is white, usually marked with a large chestnut-brown horse-shoe mark in males, hens lay up to twenty eggs in a ground nest. The nest is usually in the margin of a cereal field and these are present after around 16 weeks of age when the birds have moulted into adult plumage. Young grey partridges are mostly yellow-brown and lack the distinctive face, the song is a harsh kieerr-ik, and when disturbed, like most of the gamebirds, it flies a short distance on rounded wings, often calling rick rick rick as it rises. They are a species, but the young in particular take insects as an essential protein supply. During the first 10 days of life, the young can only digest insects, the parents lead their chicks to the edges of cereal fields, where they can forage for insects. They are also a terrestrial species, and form flocks outside the breeding season. Their numbers have fallen in these areas by as much as 85% in the last 25 years, efforts are being made in Great Britain by organizations such as the Game & Wildlife Conservation Trust to halt this decline by creating conservation headlands. In 1995, it was nominated a Biodiversity Action Plan species, gray Partridge Species Account – Cornell Lab of Ornithology Ageing and sexing by Javier Blasco-Zumeta & Gerd-Michael Heinze Feathers of Grey partridge
7.
Avian clutch size
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Clutch size refers to the number of eggs laid in a single brood by a nesting pair of birds. Several patterns of variation have been noted and the relationship between latitude and clutch size has been a topic of interest in avian reproduction and evolution. David Lack, an ornithologist and evolutionary biologist, was one of the first scientists to investigate thoroughly the effect of latitude on the number of eggs per nest, since Lacks first paper in the mid-1940s, an extensive amount of research has been conducted in this area. Most bird species show a pattern of increasing clutch size with increasing latitude. The proximate and ultimate causes for this pattern have been a subject of intense debate involving the ideas of group, david Lack observed a direct relationship between latitude and avian clutch size. Birds near the equator laid approximately half as many eggs as those that resided in northern temperate habitats and he proposed the Food Limitation Hypothesis in an attempt to explain this unique pattern. The hypothesis states that avian clutch size differences arise from differences in food availability, nature favours clutch sizes that correspond to the average maximum number of offspring that the parent can sustain given a limited food supply. Thus, the shortage of supply in tropical habitats limits avian clutch size. Furthermore, the abundance of predators near the equator as compared to regions near the poles gave rise to the Nest Predation Hypothesis. High rates of nest predation may select for smaller clutches to reduce the investment in a single nesting attempt. Moreover, larger clutches are more likely to be spotted by predators due to a rate of food delivery by the parent. This increase in parental activity will increase the probability that predators will locate nests, various studies have been performed to find supporting evidence for these two hypotheses. However, field studies have provided support for either of these hypotheses. It is clear that Lacks Food Limitation Hypothesis and the Nest Predation Hypothesis are plausible explanations for explaining the variation in avian clutch size. However, further analysis is required as field studies have provided support for these hypotheses. Few field studies have been published on this hypothesis, in another study, researchers analyzed if the rates of food delivery and nest predation explain the variation in clutch size observed among species between and within South and North America. They analyzed whether Skutch’s Hypothesis explained clutch size differences within or between latitudes, the study analyzed bird populations in large intact forests in Arizona, USA and subtropical Argentina where they monitored 1,331 nests. The authors of the study suggested analyzing parental mortality rates in southern and northern climates in addition to considering Skutch’s theory, therefore, Skutch’s Hypothesis - by itself - is not an accurate predictor of the latitudinal clutch size trend and evidence for it remain equivocal
8.
Calcium carbonate
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Calcium carbonate is a chemical compound with the formula CaCO3. It is a substance found in rocks as the minerals calcite and aragonite and is the main component of pearls and the shells of marine organisms, snails. Calcium carbonate is the ingredient in agricultural lime and is created when calcium ions in hard water react with carbonate ions to create limescale. It is medicinally used as a supplement or as an antacid. Calcium carbonate shares the properties of other carbonates. CaCO3 + CO2 + H2O → Ca2 This reaction is important in the erosion of rock, forming caverns. An unusual form of calcium carbonate is the hexahydrate, ikaite, ikaite is stable only below 6 °C. The vast majority of calcium used in industry is extracted by mining or quarrying. Pure calcium carbonate, can be produced from a quarried source. Alternatively, calcium carbonate is prepared from calcium oxide, other forms can be prepared, the denser, orthorhombic λ-CaCO3 and μ-CaCO3, occurring as the mineral vaterite. The aragonite form can be prepared by precipitation at temperatures above 85 °C, calcite contains calcium atoms coordinated by 6 oxygen atoms, in aragonite they are coordinated by 9 oxygen atoms. The vaterite structure is not fully understood, magnesium carbonate MgCO3 has the calcite structure, whereas strontium and barium carbonate adopt the aragonite structure, reflecting their larger ionic radii. Calcite, aragonite and vaterite are pure calcium carbonate minerals, industrially important source rocks which are predominantly calcium carbonate include limestone, chalk, marble and travertine. Eggshells, snail shells and most seashells are predominantly calcium carbonate, oyster shells have enjoyed recent recognition as a source of dietary calcium, but are also a practical industrial source. While not practical as a source, dark green vegetables such as broccoli. Beyond Earth, strong evidence suggests the presence of Calcium carbonate on Mars, signs of Calcium Carbonate have been detected at more than one location. This provides some evidence for the past presence of liquid water, Carbonate is found frequently in geologic settings and constitute an enormous carbon reservoir. Calcium carbonate occurs as aragonite, calcite and dolomite, the carbonate minerals form the rock types, limestone, chalk, marble, travertine, tufa, and others
9.
Passerine
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A passerine is any bird of the order Passeriformes, which includes more than half of all bird species. A notable feature of passerines compared to other orders of Aves is the arrangement of their toes, sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders, with over 5,000 identified species. It has roughly twice as many species as the largest of the mammal orders and it contains more than 110 families, the second-most of any order of tetrapods. The passerines contain several groups of parasites such as the viduas, cuckoo-finches. Most passerines are omnivorous, while the shrikes are carnivorous, the order is divided into three suborders, Tyranni, Passeri, and the basal Acanthisitti. Oscines have the best control of their syrinx muscles among birds, producing a range of songs and other vocalizations. Most passerines are smaller than members of other avian orders. The heaviest and altogether largest passerines are the thick-billed raven and the races of common raven. The superb lyrebird and some birds-of-paradise, due to long tails or tail coverts, are longer overall. The smallest passerine is the short-tailed pygmy tyrant, at 6.5 cm and 4.2 g, the foot of a passerine has three toes directed forward and one toe directed backward, called anisodactyl arrangement. This arrangement enables the birds to perch upon vertical surfaces, such as trees. The toes have no webbing or joining, but in some cotingas, the hind toe joins the leg at the same level as the front toes. The passeriformes have this toe arrangement in common with hunting birds like eagles, the leg arrangement of passerine birds contains a special adaptation for perching. This enables passerines to sleep while perching without falling off and this is especially useful for passerine birds that develop nocturnal lifestyles. Most passerine birds develop 12 tail feathers, although the superb lyrebird has 16, certain species of passerines have stiff tail feathers, which help the birds balance themselves when perching upon vertical surfaces. Some passerines, specifically in the family Ploceidae, are known for their elaborate sexual ornaments. A well-known example is the long-tailed widowbird, the chicks of passerines are altricial, blind, featherless, and helpless when hatched from their eggs. Hence, the chicks require extensive parental care, vinous-throated parrotbill has two egg colours, white and blue
10.
Zinc
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Zinc is a chemical element with the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table, in some respects zinc is chemically similar to magnesium, both elements exhibit only one normal oxidation state, and the Zn2+ and Mg2+ ions are of similar size. Zinc is the 24th most abundant element in Earths crust and has five stable isotopes, the most common zinc ore is sphalerite, a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States, Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity. Zinc metal was not produced on a large scale until the 12th century in India and was unknown to Europe until the end of the 16th century, the mines of Rajasthan have given definite evidence of zinc production going back to the 6th century BC. To date, the oldest evidence of pure zinc comes from Zawar, in Rajasthan, alchemists burned zinc in air to form what they called philosophers wool or white snow. The element was named by the alchemist Paracelsus after the German word Zinke. German chemist Andreas Sigismund Marggraf is credited with discovering pure metallic zinc in 1746, work by Luigi Galvani and Alessandro Volta uncovered the electrochemical properties of zinc by 1800. Corrosion-resistant zinc plating of iron is the application for zinc. Other applications are in batteries, small non-structural castings. A variety of compounds are commonly used, such as zinc carbonate and zinc gluconate, zinc chloride, zinc pyrithione, zinc sulfide. Zinc is an essential mineral perceived by the public today as being of exceptional biologic and public health importance, Zinc deficiency affects about two billion people in the developing world and is associated with many diseases. In children, deficiency causes growth retardation, delayed sexual maturation, infection susceptibility, enzymes with a zinc atom in the reactive center are widespread in biochemistry, such as alcohol dehydrogenase in humans. Consumption of excess zinc can cause ataxia, lethargy and copper deficiency, Zinc is a bluish-white, lustrous, diamagnetic metal, though most common commercial grades of the metal have a dull finish.6 pm. The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150 °C, above 210 °C, the metal becomes brittle again and can be pulverized by beating. Zinc is a conductor of electricity. For a metal, zinc has relatively low melting and boiling points, the melting point is the lowest of all the transition metals aside from mercury and cadmium. Many alloys contain zinc, including brass, Other metals long known to form binary alloys with zinc are aluminium, antimony, bismuth, gold, iron, lead, mercury, silver, tin, magnesium, cobalt, nickel, tellurium, and sodium
11.
Chelation
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Chelation is a type of bonding of ions and molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a ligand and a single central atom. Usually these ligands are organic compounds, and are called chelants, chelators, chelating agents, the chelate effect is the enhanced affinity of chelating ligands for a metal ion compared to the affinity of a collection of similar nonchelating ligands for the same metal. Consider the two equilibria, in solution, between the copper ion, Cu2+ and ethylenediamine on the one hand and methylamine, MeNH2 on the other. In the bidentate ligand ethylenediamine forms a complex with the copper ion. Chelation results in the formation of a five-membered CuC2N2 ring, the thermodynamic approach to describing the chelate effect considers the equilibrium constant for the reaction, the larger the equilibrium constant, the higher the concentration of the complex. Electrical charges have been omitted for simplicity of notation, the square brackets indicate concentration, and the subscripts to the stability constants, β, indicate the stoichiometry of the complex. Δ H ⊖ is the enthalpy change of the reaction. Since the enthalpy should be approximately the same for the two reactions, the difference between the two stability constants is due to the effects of entropy. In equation there are two particles on the left and one on the right, whereas in equation there are three particles on the left and one on the right. This difference means that less entropy of disorder is lost when the complex is formed than when the complex with monodentate ligands is formed. This is one of the factors contributing to the entropy difference, other factors include solvation changes and ring formation. Some experimental data to illustrate the effect are shown in the following table, other explanations, including that of Schwarzenbach, are discussed in Greenwood and Earnshaw. Numerous biomolecules exhibit the ability to dissolve certain metal cations, thus, proteins, polysaccharides, and polynucleic acids are excellent polydentate ligands for many metal ions. Organic compounds such as the amino acids glutamic acid and histidine, organic diacids such as malate, in addition to these adventitious chelators, several biomolecules are specifically produced to bind certain metals. Virtually all metalloenzymes feature metals that are chelated, usually to peptides or cofactors, such chelating agents include the porphyrin rings in hemoglobin and chlorophyll. Many microbial species produce pigments that serve as chelating agents. For example, species of Pseudomonas are known to secrete pyochelin, enterobactin, produced by E. coli, is the strongest chelating agent known
12.
Protoporphyrin IX
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Protoporphyrin IX is an organic compound, which is one of the most common porphyrins in nature. It is a deeply colored pigment that is soluble in basic water, the free porphyrin is encountered in nature in the form of its iron complexes. When complexed with iron, the molecule is called heme. Hemes are prosthetic groups in some important proteins and these heme-containing proteins include hemoglobin, myoglobin, and cytochrome c. Complexes can also be formed with metal ions, such as zinc. Its biosynthesis is mediated by the enzyme protoporphyrinogen oxidase, Protoporphyrin IX is an important precursor to biologically essential prosthetic groups such as heme, cytochrome c, and chlorophylls. As a result, a number of organisms are able to synthesize this tetrapyrrole from basic precursors such as glycine and succinyl CoA, despite the wide range of organisms that synthesize protoporphyrin IX the process is largely conserved from bacteria to mammals with a few distinct exceptions in higher plants. In heme biosynthesis, the enzyme ferrochelatase converts it into heme b, in chlorophyll biosynthesis, the enzyme magnesium chelatase converts it into Mg-protoporphyrin IX. Protoporphyrin IX reacts with iron salts in air to give the FeCl, methyl aminolevulinate Protoporphyrin for other roles of protoporphyrin IX
13.
Gene
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A gene is a locus of DNA which is made up of nucleotides and is the molecular unit of heredity. The transmission of genes to an offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes, genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes as well as gene–environment interactions, genes can acquire mutations in their sequence, leading to different variants, known as alleles, in the population. These alleles encode slightly different versions of a protein, which cause different phenotypical traits, usage of the term having a gene typically refers to containing a different allele of the same, shared gene. Genes evolve due to natural selection or survival of the fittest of the alleles, the concept of a gene continues to be refined as new phenomena are discovered. For example, regulatory regions of a gene can be far removed from its coding regions, some viruses store their genome in RNA instead of DNA and some gene products are functional non-coding RNAs. The existence of discrete inheritable units was first suggested by Gregor Mendel, from 1857 to 1864, in Brno, he studied inheritance patterns in 8000 common edible pea plants, tracking distinct traits from parent to offspring. He described these mathematically as 2n combinations where n is the number of differing characteristics in the original peas, although he did not use the term gene, he explained his results in terms of discrete inherited units that give rise to observable physical characteristics. This description prefigured the distinction between genotype and phenotype, charles Darwin developed a theory of inheritance he termed pangenesis, from Greek pan and genesis / genos. Darwin used the term gemmule to describe hypothetical particles that would mix during reproduction, de Vries called these units pangenes, after Darwins 1868 pangenesis theory. In 1909 the Danish botanist Wilhelm Johannsen shortened the name to gene, advances in understanding genes and inheritance continued throughout the 20th century. Deoxyribonucleic acid was shown to be the repository of genetic information by experiments in the 1940s to 1950s. In the early 1950s the prevailing view was that the genes in a chromosome acted like discrete entities, indivisible by recombination, collectively, this body of research established the central dogma of molecular biology, which states that proteins are translated from RNA, which is transcribed from DNA. This dogma has since shown to have exceptions, such as reverse transcription in retroviruses. The modern study of genetics at the level of DNA is known as molecular genetics, in 1972, Walter Fiers and his team at the University of Ghent were the first to determine the sequence of a gene, the gene for Bacteriophage MS2 coat protein. The subsequent development of chain-termination DNA sequencing in 1977 by Frederick Sanger improved the efficiency of sequencing, an automated version of the Sanger method was used in early phases of the Human Genome Project. The theories developed in the 1930s and 1940s to integrate molecular genetics with Darwinian evolution are called the evolutionary synthesis
14.
W chromosome
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The letters Z and W are used to distinguish this system from the XY sex-determination system. In contrast to the XY sex-determination system and the X0 sex-determination system, where the sperm determines the sex, in the ZW system, males are the homogametic sex, while females are the heterogametic sex. The Z chromosome is larger and has more genes, like the X chromosome in the XY system and these autosomes are thought to have evolved sex-determining loci that eventually developed into the respective sex chromosomes once the recombination between the chromosomes was suppressed. A paper from 2004 compared the chicken Z chromosome with platypus X chromosomes, both transcriptional and translational gene-specific dosage compensation have been observed in avian sex chromosomes. It appears possible that either condition could cause death, or that both chromosomes could be responsible for sex selection. One possible gene that could determine sex in birds is the DMRT1 gene, studies have shown that two copies of the gene are necessary for male sex determination. Although this result has been achieved in laboratory settings previously, never before has it been witnessed under natural circumstances and it is not clear as to whether the all-female snake neonates will eventually mate with a male, or reproduce asexually, or do both as does their mother. However, because of their WW chromosomes, any offspring they produce will be female, in Lepidoptera, examples of Z0, ZZW, and ZZWW females can be found. This suggests that the W chromosome is essential in female determination in some species, in Bombyx mori, the W chromosome carries the female-determining genes
15.
Common murre
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The common murre or common guillemot is a large auk. It is also known as the thin-billed murre in North America and it has a circumpolar distribution, occurring in low-Arctic and boreal waters in the North Atlantic and North Pacific. It spends most of its time at sea, only coming to land to breed on rocky shores or islands. Common murres have fast direct flight but are not very agile and they are more manoeuvrable underwater, typically diving to depths of 30–60 m. Depths of up to 180 m have been recorded, common murres breed in colonies at high densities. Nesting pairs may be in contact with their neighbours. They make no nest, their single egg is incubated on a rock ledge on a cliff face. Eggs hatch after ~30 days incubation, the chick is born downy and can regulate its body temperature after 10 days. Some 20 days after hatching the chick leaves its nesting ledge and heads for the sea, unable to fly, chicks are capable of diving as soon as they hit the water. The female stays at the nest site for some 14 days after the chick has left, both male and female common murres moult after breeding and become flightless for 1–2 months. In southern populations they occasionally return to the nest site throughout the winter, northern populations spend the winter farther from their colonies. The auks are a family of related to the gulls. The common murre is placed in the guillemot genus Uria, which it shares with the thick-billed murre or Brunnichs guillemot and these species, together with the razorbill, little auk and the extinct great auk make up the tribe Alcini. This arrangement was based on analyses of auk morphology and ecology. The binomial name derives from Greek ouriaa, a waterbird mentioned by Athenaeus, the English guillemot is from French guillemot, probably derived from Guillaume, William. Murre is of uncertain origins, but may imitate the call of the common guillemot, the common murre is 38–46 cm in length with a 61–73 cm wingspan. Male and female are indistinguishable in the field and weight ranges between 945 g in the south of their range to 1,044 g in the north, a weight range of 775–1,250 g has been reported. In breeding plumage, the subspecies is black on the head, back and wings
16.
Cormorant
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Phalacrocoracidae is a family of some 40 species of aquatic birds commonly known as cormorants and shags. Several different classifications of the family have been proposed recently, there is no consistent distinction between cormorants and shags as these appellations have been assigned to different species randomly. Cormorants and shags are medium-to-large birds, with weight in the range of 0. 35–5 kilograms. The majority of species have dark feathers, the bill is long, thin and hooked. Their feet have webbing between all four toes, all species are fish-eaters, catching the prey by diving from the surface. They are excellent divers, and under water they propel themselves with their feet with help from their wings and they have relatively short wings due to their need for economical movement underwater, and consequently have the highest flight costs of any bird. Cormorants nest in colonies around the shore, on trees, islets or cliffs and they are coastal rather than oceanic birds, and some have colonised inland waters – indeed, the original ancestor of cormorants seems to have been a fresh-water bird. They range around the world, except for the central Pacific islands, no consistent distinction exists between cormorants and shags. The names cormorant and shag were originally the names of the two species of the family found in Great Britain, Phalacrocorax carbo and P. aristotelis. Shag refers to the birds crest, which the British forms of the great cormorant lack, as other species were discovered by English-speaking sailors and explorers elsewhere in the world, some were called cormorants and some shags, depending on whether they had crests or not. Sometimes the same species is called a cormorant in one part of the world and a shag in another, e. g. the great cormorant is called the black shag in New Zealand. Van Tets proposed to divide the family into two genera and attach the name cormorant to one and shag to the other, but this flies in the face of common usage and has not been widely adopted. The scientific genus name is Latinised Ancient Greek, from φαλακρός, Cormorant is a contraction derived either directly from Latin corvus marinus, sea raven or through Brythonic Celtic. Cormoran is the Cornish name of the sea giant in the tale of Jack the Giant Killer, indeed, sea raven or analogous terms were the usual terms for cormorants in Germanic languages until after the Middle Ages. Cormorants and shags are medium-to-large seabirds and they range in size from the pygmy cormorant, at as little as 45 cm and 340 g, to the flightless cormorant, at a maximum size 100 cm and 5 kg. The recently extinct spectacled cormorant was rather larger, at a size of 6.3 kg. The majority, including nearly all Northern Hemisphere species, have dark plumage, but some Southern Hemisphere species are black and white. Many species have areas of coloured skin on the face which can be blue, orange, red or yellow
17.
Tinamou
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Tinamous form an order, comprising a single family with two distinct subfamilies, containing 47 species of birds found in Mexico, Central America, and South America. The word tinamou comes from the Galibi term for these birds, one of the most ancient living groups of bird, they first appear in the fossil record in the Miocene epoch. Tinamous have traditionally regarded as the sister group of the flightless ratites. They are generally sedentary, ground-dwelling and, though not flightless and they are found in a variety of habitats, ranging from semi-arid alpine grasslands to tropical rainforests. The two subfamilies are divided by habitat, with the Nothurinae referred to as steppe or open country tinamous. Although some species are common, tinamous are shy and secretive birds. They are active during the day, retiring to roosts at night and they generally have cryptic plumage, with males and females similar in appearance, though the females are usually larger. They are opportunistic and omnivorous feeders, consuming a variety of plant and animal food from fruits and seeds to worms, insects. They will dust-bathe as well as wash themselves by standing in heavy rain and they are heard more often than seen, communicating with each other by a variety of frequently given, characteristic calls, especially during the breeding season. With occasional exceptions, a male maintains a territory and a nesting site during the breeding season which a succession of females will visit. Females will wander through several territories mating with, and laying eggs in the nests of, nests are always on the ground, concealed in vegetation or among rocks. Eggs are relatively large and glossy, often brightly colored when laid, the chicks can run soon after hatching and are largely self-sufficient at three weeks old. Tinamous and their eggs have many predators, from falcons. They have also been hunted by humans and sometimes persecuted as agricultural pests. However, the threat to their populations is from habitat destruction through land clearing. Seven species are listed as vulnerable and another seven as near-threatened and they feature in the mythology of the indigenous peoples of their range. Often translocated and easily bred in captivity, they have never been successfully domesticated, the tinamou family consists of about 47 species in nine genera. The two subfamilies are the Nothurinae, the tinamous, and the Tinaminae, the forest tinamous
18.
Duck
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Duck is the common name for a large number of species in the waterfowl family Anatidae, which also includes swans and geese. The ducks are divided among several subfamilies in the family Anatidae, they do not represent a group but a form taxon, since swans. Ducks are mostly birds, mostly smaller than the swans and geese. Ducks are sometimes confused with several types of unrelated water birds with similar forms, such as loons or divers, grebes, gallinules and this word replaced Old English ened/ænid duck, possibly to avoid confusion with other Old English words, like ende end with similar forms. Other Germanic languages still have similar words for duck, for example, Dutch eend duck, the word ened/ænid was inherited from Proto-Indo-European, compare, Latin anas duck, Lithuanian ántis duck, Ancient Greek nēssa/nētta duck, and Sanskrit ātí water bird, among others. A duckling is a duck in downy plumage or baby duck. A male duck is called a drake and the female is called a duck, the overall body plan of ducks is elongated and broad, and the ducks are also relatively long-necked, albeit not as long-necked as the geese and swans. The body shape of diving ducks varies somewhat from this in being more rounded, the bill is usually broad and contains serrated lamellae, which are particularly well defined in the filter-feeding species. In the case of some fishing species the bill is long, the scaled legs are strong and well developed, and generally set far back on the body, more so in the highly aquatic species. The wings are strong and are generally short and pointed. Three species of duck are almost flightless, however. Many species of duck are temporarily flightless while moulting, they seek out protected habitat with good food supplies during this period, the drakes of northern species often have extravagant plumage, but that is moulted in summer to give a more female-like appearance, the eclipse plumage. The plumage of birds generally resembles that of the female. Over the course of evolution, female ducks have evolved to have a corkscrew shaped vagina to prevent rape, Ducks exploit a variety of food sources such as grasses, aquatic plants, fish, insects, small amphibians, worms, and small molluscs. Dabbling ducks feed on the surface of water or on land, along the edge of the beak there is a comb-like structure called a pecten. This strains the water squirting from the side of the beak, the pecten is also used to preen feathers and to hold slippery food items. Diving ducks and sea ducks forage deep underwater, to be able to submerge more easily, the diving ducks are heavier than dabbling ducks, and therefore have more difficulty taking off to fly. A few specialized species such as the mergansers are adapted to catch, to avoid injury when digging into sediment it has no cere, but the nostrils come out through hard horn
19.
Cassowary
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The cassowaries are ratites in the genus Casuarius and are native to the tropical forests of New Guinea, nearby islands, and northeastern Australia. The most common of these, the cassowary, is the third-tallest and second-heaviest living bird, smaller only than the ostrich. Cassowaries are very shy, but when provoked they are capable of inflicting injuries, occasionally fatal, to dogs, cassowaries are part of the ratite group, which also includes the emu, rheas, ostriches, and kiwi, and the extinct moas and elephant birds. g. The taxonomic name C. papuanus may also be in need of revision to Casuarius westermanni, the evolutionary history of cassowaries, as of all ratites, is not well known. A fossil species was reported from Australia, but for reasons of biogeography this assignment is not certain and it might belong to the prehistoric Emuarius, the northern and dwarf cassowaries are not well known. All cassowaries are usually shy birds of the deep forest, adept at disappearing long before a human knows they are there, even the more accessible southern cassowary of the far north Queensland rain forests is not well researched. Females are bigger and more brightly coloured, adult southern cassowaries are 1.5 to 1.8 m tall, although some females may reach 2 m, and weigh 58.5 kg. All cassowaries have feathers that consist of a shaft and loose barbules and they do not have retrices or a preen gland. Cassowaries have small wings with 5–6 large remeges and these are reduced to stiff, keratinous quills, like porcupine quills, with no barbs. A claw is on each second finger, the furcula and coracoid are degenerate, and their palatal bones and sphenoid bones touch each other. These, along with their body, are thought to be adaptations to ward off vines, thorns. Cassowaries have three-toed feet with sharp claws, the second toe, the inner one in the medial position, sports a dagger-like claw that can be 125 mm long. This claw is particularly fearsome since cassowaries sometimes kick humans and animals with their powerful legs. Cassowaries can run at up to 50 km/h through the dense forest and they are good swimmers, crossing wide rivers and swimming in the sea. All three species have a keratinous skin-covered casque on their heads which grows with age, the casques shape and size, up to 18 cm, is species-dependent. Casuarius casuarius has the largest and Casuarius bennetti the smallest, with Casuarius unappendiculatus having variations in between, contrary to earlier findings, the hollow inside of the casque is spanned with fine fibres which are believed to have an acoustic function. Several functions for the casque have been proposed, one is that they are a secondary sexual characteristic. Other suggested functions include being used to batter through underbrush, as a weapon in dominance disputes, the latter three are disputed by biologist Andrew Mack, whose personal observation suggests that the casque amplifies deep sounds
20.
Chicken
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The chicken is a type of domesticated fowl, a subspecies of the red junglefowl. It is one of the most common and widespread domestic animals, humans keep chickens primarily as a source of food, consuming both their meat and their eggs. From India, the chicken was imported to Lydia in western Asia Minor. In the UK and Ireland adult male chickens over the age of one year are known as cocks, whereas in America, Australia. Males less than a year old are cockerels, females over a year old are known as hens and younger females as pullets although in the egg-laying industry, a pullet becomes a hen when she begins to lay eggs at 16 to 20 weeks of age. In Australia and New Zealand, there is a generic term chook /ˈtʃʊk/ to describe all ages, the young are called chicks and the meat is called chicken. Chicken originally referred to domestic fowl. The species as a whole was then called domestic fowl, or just fowl. This use of chicken survives in the phrase Hen and Chickens, sometimes used as a British public house or theatre name, the word chicken is sometimes erroneously construed to mean females exclusively, despite the term hen for females being in wide circulation. In the Deep South of the United States chickens are also referred to by the slang term yardbird, in the wild, they often scratch at the soil to search for seeds, insects and even animals as large as lizards, small snakes or young mice. Chickens may live for five to ten years, depending on the breed, the worlds oldest chicken was a hen which died of heart failure at the age of 16 according to Guinness World Records. However, in some breeds, such as the Sebright chicken, the rooster has only slightly pointed neck feathers, the identification can be made by looking at the comb, or eventually from the development of spurs on the males legs. Adult chickens have a fleshy crest on their heads called a comb, or cockscomb, collectively, these and other fleshy protuberances on the head and throat are called caruncles. Both the adult male and female have wattles and combs, a muff or beard is a mutation found in several chicken breeds which causes extra feathering under the chickens face, giving the appearance of a beard. Domestic chickens are not capable of long distance flight, although birds are generally capable of flying for short distances. Chickens may occasionally fly briefly to explore their surroundings, but generally do so only to flee perceived danger, Chickens are gregarious birds and live together in flocks. They have an approach to the incubation of eggs and raising of young. Individual chickens in a flock will dominate others, establishing an order, with dominant individuals having priority for food access
21.
Little bee-eater
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The little bee-eater is a near passerine bird in the bee-eater family Meropidae. It is resident in much of Sub-Saharan Africa and it should not be confused with the little green bee-eater, Merops orientalis. Migration is limited to seasonal movements depending on rainfall patterns and this species, like other bee-eaters, is a rich and brightly coloured slender bird. It has green upper parts, yellow throat, black gorget, the wings are green and brown, and the beak is black. It reaches a length of 15–17 cm, which makes it the smallest African bee-eater, often silent, their call is a soft seep. This is an abundant and tame bird, familiar throughout its range, there have been estimated to be between 60-80 million little bee-eaters. It breeds in open country with bushes, preferably near water, just as the name suggests, bee-eaters predominantly eat insects, especially bees, wasps and hornets, which are caught in the air by sorties from an open perch. This species often hunts from low perches, maybe only a metre or less high, before eating its meal, a bee-eater removes the sting by repeatedly hitting the insect on a hard surface. Unlike most bee-eaters, these are solitary nesters, making a tunnel in sandy banks and they lay 4 to 6 spherical white eggs. Both the male and the take care of the eggs. These birds roost communally, lined up on a tree branch
22.
Oval
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An oval is a closed curve in a plane which loosely resembles the outline of an egg. The term is not very specific, but in areas it is given a more precise definition. In common English, the term is used in a broader sense, the three-dimensional version of an oval is called an ovoid. The term oval when used to describe curves in geometry is not well-defined, many distinct curves are commonly called ovals or are said to have an oval shape. Generally, to be called an oval, a plane curve should resemble the outline of an egg or an ellipse, the adjectives ovoidal and ovate mean having the characteristic of being an ovoid, and are often used as synonyms for egg-shaped. In the theory of planes, an oval is a set of n +1 points in a projective plane of order n. An ovoid in the projective geometry PG is a set of q2 +1 points such that no three points are collinear. At each point of an all the tangent lines to the ovoid lie in a single plane. The shape of an egg is approximated by long half of a spheroid, joined to a short half of a roughly spherical ellipsoid. These are joined at the equator and sharing a principal axis of rotational symmetry, although the term egg-shaped usually implies a lack of reflection symmetry across the equatorial plane, it may also refer to true prolate ellipsoids. It can also be used to describe the 2-dimensional figure that, if revolved around its major axis, in technical drawing, an oval is a figure constructed from two pairs of arcs, with two different radii. The arcs are joined at a point in which lines tangential to both joining arcs lie on the line, thus making the joint smooth. Any point of an oval belongs to an arc with a constant radius, but in an ellipse, in common speech, oval means a shape rather like an egg or an ellipse, which may be two-dimensional or three-dimensional. It also often refers to a figure that resembles two semicircles joined by a rectangle, like a cricket infield, speed skating rink or an athletics track, however, this is more correctly called a stadium or archaically, an oblong. Sometimes, it can refer to any rectangle with rounded corners. The shape lends its name to many well-known places, ellipse Stadium Vesica piscis – a pointed oval
23.
Oviduct
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In vertebrates, other than mammals, the passageway from the ovaries to the outside of the body is known as the oviduct. In female mammals this passageway is known as the tube or Fallopian tube. The eggs travel along the oviduct and these eggs will either be fertilized by sperm to become a zygote, or will degenerate in the body. Normally, these are paired structures, but in birds and some fishes, one or the other side fails to develop. Except in teleosts, the oviduct does not directly contact the ovary, instead, the most anterior portion ends in a funnel-shaped structure called the infundibulum, which collects eggs as they are released by the ovary into the body cavity. The only female vertebrates to lack oviducts are the jawless fishes, in these species, the single fused ovary releases eggs directly into the body cavity. The fish eventually extrudes the eggs through small genital pores towards the rear of the body, in amphibians and lungfishes, the oviduct is a simple ciliated tube, lined with mucus-secreting glands that produce the jelly that surrouns the ovum. In all other vertebrates, there is some degree of specialisation of the tube. In cartilaginous fishes, the portion of the tube develops as a shell gland. The first portion of this secretes the egg white, while the lower portion secretes a hard, horny. Below the shell gland is the ovisac, a region in which eggs are stored prior to laying. In ovoviviparous species, the egg remains within the ovisac until it hatches, some cartilaginous fishes, however, are truly viviparous, giving birth to live young, and producing no egg shell. In these forms, the ovisac nurtures the developing embryo, often with the aid of vascular outgrowths similar to, but much simpler than, the ovary itself is hollow, with eggs being shed into the central cavity, and thence passing directly into the oviduct. In amniotes – reptiles, birds, and mammals – the egg is enclosed with a layer, or amnion. In reptiles, birds, and monotremes, the part of the oviduct is a muscular tube. This part of the oviduct is lined with glands that secrete the components of the egg white, the lower portion of the oviduct, or uterus, has a thicker layer of smooth muscle and contains the glands that secrete the egg shell. In marsupials and placental mammals, the uterus becomes lined by an endometrium, in many placental mammals, the uteri of each side become partially or wholly fused into a single organ, although in marsupials they remain completely separate. In mammals, the portion of the oviduct above the uterus is referred to as the Fallopian tube, for birds, the oviduct is composed of, Infundibulum Magnum Isthmus Shell gland Vaginal homologue Fallopian tube Romer, Alfred Sherwood, Parsons, Thomas S
24.
Peristalsis
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Peristalsis is a radially symmetrical contraction and relaxation of muscles that propagates in a wave down a tube, in an anterograde direction. In much of a digestive tract such as the human gastrointestinal tract, smooth muscle contracts in sequence to produce a peristaltic wave. Earthworms use a mechanism to drive their locomotion, and some modern machinery imitates this design. The word comes from New Latin and is derived from the Greek peristellein, to wrap around, from peri-, around + stellein, draw in, bring together, after food is chewed into a bolus, it is swallowed and moved through the esophagus. Smooth muscles contract behind the bolus to prevent it from being squeezed back into the mouth, then rhythmic, unidirectional waves of contractions work to rapidly force the food into the stomach. The migrating motor complex helps trigger peristaltic waves and this process works in one direction only and its sole esophageal function is to move food from the mouth into the stomach. In the esophagus, two types of peristalsis occur, First, there is a primary peristaltic wave, which occurs when the bolus enters the esophagus during swallowing, the primary peristaltic wave forces the bolus down the esophagus and into the stomach in a wave lasting about 8–9 seconds. The wave travels down to the even if the bolus of food descends at a greater rate than the wave itself. The process of peristalsis is controlled by medulla oblongata, esophageal peristalsis is typically assessed by performing an esophageal motility study. During vomiting, the propulsion of food up the oesophagus and out the mouth comes from contraction of the abdominal muscles, once processed and digested by the stomach, the milky chyme is squeezed through the pyloric sphincter into the small intestine. Once past the stomach, a typical peristaltic wave only lasts for a few seconds and its primary purpose is to mix the chyme in the intestine rather than to move it forward in the intestine. Through this process of mixing and continued digestion and absorption of nutrients, in contrast to peristalsis, segmentation contractions result in that churning and mixing without pushing materials further down the digestive tract. Although the large intestine has peristalsis of the type that the small intestine uses, instead, general contractions called mass movements occur one to three times per day in the large intestine, propelling the chyme toward the rectum. Mass movements often tend to be triggered by meals, as the presence of chyme in the stomach, the human lymphatic system has no central pump. Instead, lymph circulates through peristalsis in the capillaries, as well as valves in the capillaries, compression during contraction of adjacent skeletal muscle. During ejaculation, the muscle in the walls of the vas deferens contracts reflexively in peristalsis. The earthworm is an annelid worm with a hydrostatic skeleton that moves by peristalsis. Its hydrostatic skeleton consists of a body cavity surrounded by an extensible body wall
25.
Cloaca
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In animal anatomy, a cloaca /kloʊˈeɪkə/ kloh-AY-kə is the posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts of certain animals, opening at the vent. Excretory systems with analogous purpose in certain invertebrates are sometimes referred to as cloacae. The cloacal region is often associated with a secretory organ, the cloacal gland, which has been implicated in the scent-marking behavior of some reptiles, amphibians. The word comes from Latin, and means sewer, derived from cluō, birds reproduce using their cloaca, this occurs during a cloacal kiss in most birds. Birds that mate using this method touch their cloacae together, in species for only a few seconds. The reproductive system must be re-engorged before the season of each species. Such regeneration usually takes about a month, birds generally produce one batch of eggs per year, but they will produce another if the first is taken away. For some birds, such as ostriches, cassowaries, kiwi, geese, and some species of swans and ducks, the males do not use the cloaca for reproduction, in those, the penis helps ensure water does not wash away the males sperm during copulation. One study has looked into birds that use their cloaca for cooling, among fish, a true cloaca is present only in elasmobranchs and lobe-finned fishes. In lampreys and in some ray-finned fishes, part of the remains in the adult to receive the urinary and reproductive ducts. In chimaeras and most teleosts, however, all three openings are entirely separated, with a few exceptions noted below, mammals have no cloacae. Even in those that have one, the cloaca is partially subdivided into regions for the anus. The monotremes possess a true cloaca, in marsupials, the genital tract is separate from the anus, but a trace of the original cloaca does remain externally. Unlike other marsupials, marsupial moles have a cloaca, a fact that has been argued against a marsupial identity for these mammals. Most adult placental mammals have no remaining trace of the cloaca, however, the tenrecs and golden moles, small placental mammals native to Africa, as well as some shrews retain a cloaca as adults. Being placental animals, humans only have a cloaca, which is split up into separate tracts during the development of the urinary. However, a few human congenital disorders result in persons being born with a cloaca, including persistent cloaca, some species have modified cloacae for increased gas exchange. This is where reproductive activity occurs, some turtles, especially those specialized in diving, are highly reliant on cloacal respiration during dives
26.
Calcification
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Calcification is the accumulation of calcium salts in a body tissue. It normally occurs in the formation of bone, but calcium can be deposited abnormally in soft tissue, calcifications may be classified on whether there is mineral balance or not, and the location of the calcification. Calcification may also refer to the processes of mineral deposition in biological systems. Calcification of soft tissue can be caused by vitamin K2 deficiency or by calcium absorption due to a high calcium/vitamin D ratio. This can occur with or without a mineral imbalance, such metastatic soft tissue calcification is mainly in tissues containing calcium catchers such as elastic fibres or sour mucopolysaccharides. These tissues especially include the lungs and the aorta, dystrophic calcification, without a systemic mineral imbalance. Metastatic calcification, an elevation of calcium levels in the blood. Calcification can manifest itself in ways in the body. Laminated appearance suggests granulomatous disease while popcorn calcification indicates hamartoma, malignant lesions may have stippled or eccentric calcification. In a number of breast pathologies, calcium is deposited at sites of cell death or in association secretions or hyalinized stroma. For example, small, irregular, linear calcifications may be seen, via mammography, treatment of high calcium/vitamin D ratio may most easily be accomplished by intake of more vitamin D if vitamin K is normal. Intake of too much vitamin D would be evident by anorexia, loss of appetite, or soft tissue calcification
27.
X-ray
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X-radiation is a form of electromagnetic radiation. Most X-rays have a wavelength ranging from 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz, X-ray wavelengths are shorter than those of UV rays and typically longer than those of gamma rays. Spelling of X-ray in the English language includes the variants x-ray, xray, X-rays with high photon energies are called hard X-rays, while those with lower energy are called soft X-rays. Due to their ability, hard X-rays are widely used to image the inside of objects, e. g. in medical radiography. The term X-ray is metonymically used to refer to an image produced using this method. Since the wavelengths of hard X-rays are similar to the size of atoms they are useful for determining crystal structures by X-ray crystallography. By contrast, soft X-rays are easily absorbed in air, the length of 600 eV X-rays in water is less than 1 micrometer. There is no consensus for a definition distinguishing between X-rays and gamma rays, one common practice is to distinguish between the two types of radiation based on their source, X-rays are emitted by electrons, while gamma rays are emitted by the atomic nucleus. This definition has problems, other processes also can generate these high-energy photons. One common alternative is to distinguish X- and gamma radiation on the basis of wavelength, with radiation shorter than some arbitrary wavelength, such as 10−11 m and this criterion assigns a photon to an unambiguous category, but is only possible if wavelength is known. Occasionally, one term or the other is used in specific contexts due to precedent, based on measurement technique. Thus, gamma-rays generated for medical and industrial uses, for radiotherapy, in the ranges of 6–20 MeV. X-ray photons carry enough energy to ionize atoms and disrupt molecular bonds and this makes it a type of ionizing radiation, and therefore harmful to living tissue. A very high radiation dose over a period of time causes radiation sickness. In medical imaging this increased risk is generally greatly outweighed by the benefits of the examination. The ionizing capability of X-rays can be utilized in treatment to kill malignant cells using radiation therapy. It is also used for material characterization using X-ray spectroscopy, hard X-rays can traverse relatively thick objects without being much absorbed or scattered. For this reason, X-rays are widely used to image the inside of visually opaque objects, the most often seen applications are in medical radiography and airport security scanners, but similar techniques are also important in industry and research
28.
Science (journal)
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Science, also widely referred to as Science Magazine, is the peer-reviewed academic journal of the American Association for the Advancement of Science and one of the worlds top academic journals. It was first published in 1880, is circulated weekly and has a print subscriber base of around 130,000. Because institutional subscriptions and online access serve an audience, its estimated readership is 570,400 people. Unlike most scientific journals, which focus on a field, Science. According to the Journal Citation Reports, Sciences 2015 impact factor was 34.661, although it is the journal of the AAAS, membership in the AAAS is not required to publish in Science. Papers are accepted from authors around the world, competition to publish in Science is very intense, as an article published in such a highly cited journal can lead to attention and career advancement for the authors. Fewer than 7% of articles submitted are accepted for publication, Science is based in Washington, D. C. United States, with an office in Cambridge, England. Science was founded by New York journalist John Michels in 1880 with financial support from Thomas Edison, however, the journal never gained enough subscribers to succeed and ended publication in March 1882. Entomologist Samuel H. Scudder resurrected the journal one year later and had some success while covering the meetings of prominent American scientific societies, however, by 1894, Science was again in financial difficulty and was sold to psychologist James McKeen Cattell for $500. In an agreement worked out by Cattell and AAAS secretary Leland O. Howard, after Cattell died in 1944, the ownership of the journal was transferred to the AAAS. After Cattells death in 1944, the journal lacked a consistent editorial presence until Graham DuShane became editor in 1956. In 1958, under DuShanes leadership, Science absorbed The Scientific Monthly, physicist Philip Abelson, a co-discoverer of neptunium, served as editor from 1962 to 1984. Under Abelson the efficiency of the process was improved and the publication practices were brought up to date. During this time, papers on the Apollo program missions and some of the earliest reports on AIDS were published, biochemist Daniel E. Koshland, Jr. served as editor from 1985 until 1995. From 1995 until 2000, neuroscientist Floyd E. Bloom held that position, biologist Donald Kennedy became the editor of Science in 2000. Biochemist Bruce Alberts took his place in March 2008, geophysicist Marcia McNutt became editor-in-chief in June 2013. During her tenure the family of journals expanded to include Science Robotics and Science Immunology, jeremy M. Berg became editor-in-chief on July 1,2016
29.
Spur-winged lapwing
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For other species called Spur-winged Lapwing or Spur-winged Plover, see below. The spur-winged lapwing or spur-winged plover is a species, one of a group of largish waders in the family Charadriidae. It is one of several species of wader supposed to be the bird said by Herodotus to have been involved in an unattested cleaning symbiosis with the Nile crocodile. The spur-winged lapwing breeds around the eastern Mediterranean, and in a band from sub-Saharan west Africa to Arabia. The Greek and Turkish breeders are migratory, but other populations are resident, the species is declining in its northern range, but is abundant in much of tropical Africa, being seen at almost any wetland habitat in its range. The spur-winged lapwing is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds applies and these are conspicuous and unmistakable birds. They are medium-large waders with black crown, chest, foreneck stripe, the face, the rest of the neck and belly are white and the wings and back are light brown. The bill and legs are black and its striking appearance is supplemented by its noisy nature, with a loud did-he-do-it call. The birds common name refers to a claw or spur hidden in each of its wings. This species has a preference for marshes and similar freshwater wetland habitats, the food of the spur-winged lapwing is insects and other invertebrates, which are picked from the ground. It lays two blotchy yellowish eggs on a ground scrape, the spur-winged lapwing is known to sometimes use the wing-claws in an attack on animals and, rarely, people, who get too close to the birds exposed offspring. The spur-winged plover of southern Australasia is a different species, Vanellus miles, a similar-looking species, Vanellus duvaucelii, from Southeast Asia was also called spur-winged lapwing while V. spinosus was referred to as a plover. Its common name has changed to river lapwing. However, there is no evidence that this or any other species in fact has such a relationship. BirdLife species factsheet for Vanellus spinosus Vanellus spinosus, Spur-winged lapwing photo gallery at VIREO Interactive range map of Vanellus spinosus at IUCN Red List maps Audio recordings of Spur-winged lapwing on Xeno-canto
30.
Senegal parrot
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The Senegal parrot is a Poicephalus parrot which is a resident breeder across a wide range of west Africa. It makes migrations within west Africa, according to the availability of the fruit, seeds and it is considered a farm pest in Africa, often feeding on maize or millet. They do not differ in behaviour, but only in the colour of the vest, in the pet trade, the nominate subspecies is the most common though all three are raised and sold as pets. P. s. senegalus, this subspecies has a yellow vest, its range includes Senegal, southern Mauritania, southern Mali to Guinea. P. s. mesotypus, this subspecies has an orange vest, its range is eastern and northeastern Nigeria. P. s. versteri, this subspecies has a deep-orange/red vest, its range is from the Ivory Coast, Senegal parrots are birds of open woodland and savanna. They flock most commonly in countries in West Africa and it is a gregarious species, continuously chattering with a range of whistling and squawking calls. Senegal parrots live an average of approximately 25–30 years in the wild, Senegal parrots are about 23 centimetres long, weigh about 120 to 170 grams. They have a large head and beak for their overall size. Adults have a grey head, grey beak, bright yellow irises, green back and throat. The yellow and green areas on a Senegal parrots front form a V-shape resembling a yellow vest worn over green, young Juveniles have dark grey, almost black, irises, which change to light grey. The females beak and head are slightly smaller and narrower than the males. The under-tail covert feathers are mostly yellow in the male. Males are generally, but not always, larger and heavier than female birds, Senegal parrots nest in holes in trees, often oil palms, usually laying three to four white eggs. The eggs are about 3 centimetres long by 2.5 centimetres wide, the eggs are incubated by the female, starting after the second egg has been laid, for about 27 to 28 days. Newly hatched chicks have a white down and they do not open their eyes until about two to three weeks after hatching. They are dependent on the female for food and warmth who remains in the nest most of the time until four weeks after hatching when the chicks have enough feathers for heat insulation. During this time the male brings food for the female and chicks, from about two to four weeks after hatching the female also begins to collect food for the chicks
31.
Bee hummingbird
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The bee hummingbird, zunzuncito or Helena hummingbird is a species of hummingbird regarded as the worlds smallest bird. With a mass around 1. 6–2 g and a length of 5–6 cm, the male has the green pileum and fiery red throat, iridescent gorget with elongated lateral plumes, bluish upper-parts, and the rest of the underparts mostly greyish white. The male is smaller than the female, the female is green above, whitish below, with white tips to the outer tail feathers. Compared to other small hummingbirds, which often have a slender appearance, female bee hummingbirds are bluish green with a pale gray underside. The tips of their feathers have white spots. During the mating season, males have a reddish to pink head, chin, the female lays only two eggs at a time, each about the size of a coffee bean. As the smallest bird in the world, its weight is less than 2 grams or about equal in mass to a United States dime, as its name suggests, it is scarcely larger than a bee. Like all hummingbirds, it is a swift, strong flier, the brilliant, iridescent colors of the bee hummingbirds feathers make the bird seem like a tiny jewel. The iridescence is not always noticeable, but depends on the angle at which a person looks at the bird, the birds slender, pointed bill is adapted for probing deep into flowers. The bee hummingbird feeds mainly on nectar, and an insect or spider, by moving its tongue rapidly in. In the process of feeding, the bird picks up pollen on its bill, when it flies from flower to flower, it transfers the pollen. In this way, it plays an important role in plant reproduction, in one day, the bee hummingbird may visit 1,500 flowers. Using bits of cobwebs, bark, and lichen, the bee hummingbird builds a cup-shaped nest that is only about 2.5 cm in diameter. Nests have been built on single clothespins and she lines the nest with soft plant fibers. In this nest she lays her eggs, which are no bigger than peas and she alone incubates the eggs and raises the young. The bee hummingbird has been reported to visit 15 plant species from 15 different genera, however, in more recent studies, only 10 were found, nine of them were found to be endemic to Cuba. Mellisuga helenae is endemic to the entire Cuban archipelago, including the island of Cuba. It is found mainly in Cubas mogote area and uncommonly in Playa Larga near Zapata swamp, the bee hummingbirds breeding season is from March–June
32.
Common ostrich
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The ostrich or common ostrich is either one or two species of large flightless birds native to Africa, the only living member of the genus Struthio, which is in the ratite family. In 2014, the Somali ostrich was recognized as a distinct species, the common ostrich shares the order Struthioniformes with the kiwis, emus, rheas, and cassowaries. However, phylogenetic studies have shown that it is the group to all other members of Palaeognathae. It is distinctive in its appearance, with a neck and legs, and can run at up to about 70 km/h. The common ostrich is the largest living species of bird and lays the largest eggs of any living bird, the common ostrichs diet consists mainly of plant matter, though it also eats invertebrates. It lives in groups of 5 to 50 birds. When threatened, the ostrich will either hide itself by lying flat against the ground, if cornered, it can attack with a kick of its powerful legs. Mating patterns differ by region, but territorial males fight for a harem of two to seven females. The common ostrich is farmed around the world, particularly for its feathers and its skin is used for leather products and its meat is marketed commercially, with its leanness a common marketing point. Common ostriches usually weigh from 63 to 145 kilograms, or as much as two adult humans, ostriches of the East African race averaged 115 kg in males and 100 kg in females, while the nominate subspecies was found to average 111 kg in unsexed adults. Exceptional male ostriches can weigh up to 156.8 kg, at sexual maturity, male common ostriches can be from 2.1 to 2.8 m in height, while female common ostriches range from 1.7 to 2.0 m tall. New chicks are fawn in colour, with brown spots. During the first year of life, chicks grow at about 25 cm per month, at one year of age, common ostriches weigh approximately 45 kilograms. Their lifespan is up to 40–45 years, the feathers of adult males are mostly black, with white primaries and a white tail. However, the tail of one subspecies is buff, females and young males are greyish-brown and white. The head and neck of both male and female ostriches is nearly bare, with a layer of down. The skin of the neck and thighs is pinkish gray. The eyes are shaded from sunlight from above, However, the head and bill are relatively small for the birds huge size, with the bill measuring 12 to 14.3 cm
33.
Kiwi
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Kiwi or kiwis are flightless birds native to New Zealand, in the genus Apteryx and family Apterygidae. At around the size of a chicken, kiwi are by far the smallest living ratites. DNA sequence comparisons have yielded the surprising conclusion that kiwi are much more related to the extinct Malagasy elephant birds than to the moa with which they shared New Zealand. There are five recognised species, two of which are vulnerable, one of which is endangered, and one of which is critically endangered. All species have negatively affected by historic deforestation but currently the remaining large areas of their forest habitat are well protected in reserves. At present, the greatest threat to their survival is predation by mammalian predators. The kiwi is a symbol of New Zealand, and the association is so strong that the term Kiwi is used internationally as the colloquial demonym for New Zealanders. The Māori language word kiwi is generally accepted to be of imitative origin from the call, with its long decurved bill and brown body, the curlew resembles the kiwi. So when the first Polynesian settlers arrived, they may have applied the word kiwi to the new-found bird, the genus name Apteryx is derived from Ancient Greek without wing, a-, without or not, pterux, wing. The name is usually uncapitalised, with the either the anglicised kiwis or, consistent with the Māori language. There are five species of kiwi, as well as a number of subspecies. Relationships in the genus Apteryx The largest species is the great spotted kiwi or Roroa, Apteryx haastii and it has grey-brown plumage with lighter bands. The female lays just one egg, which both parents then incubate, the population is estimated to be over 20,000, distributed through the more mountainous parts of northwest Nelson, the northern West Coast, and the Southern Alps. The small little spotted kiwi, Apteryx owenii is unable to withstand predation by introduced pigs, stoats and cats, about 1350 remain on Kapiti Island. It has been introduced to other islands and appears to be becoming established with about 50 Little Spots on each island. A docile bird the size of a bantam, it stands 25 cm high and she lays one egg, which is incubated by the male. Females lay as many as three eggs in a season, each one in a different nest, the distribution of these kiwi is limited to a small area on the west coast of the South Island of New Zealand. The southern brown kiwi, Tokoeka, or Common kiwi, Apteryx australis, is a common species of kiwi, known from south and west parts of the South Island
34.
Eurasian oystercatcher
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The Eurasian oystercatcher also known as the common pied oystercatcher, or palaearctic oystercatcher, or just oystercatcher, is a wader in the oystercatcher bird family Haematopodidae. It is the most widespread of the oystercatchers, with three races breeding in western Europe, central Eurasia, Kamchatka, China, and the western coast of Korea, no other oystercatcher occurs within this area. This oystercatcher is the bird of the Faroe Islands. The oystercatcher is one of the largest waders in the region and it is 40–45 cm long, the bill accounting for 8–9 cm, and has a wing-span of 80–85 cm. They are obvious and noisy birds, with black and white plumage, red legs. Despite its name, oysters do not form a part of its diet. The bird still lives up to its name, as few if any other wading birds are capable of opening oysters at all and this oystercatcher is unmistakable in flight, with white patches on the wings and tail, otherwise black upperparts, and white underparts. Young birds are brown, have a white neck collar. The call is a distinctive loud piping, the bill shape varies, oystercatchers with broad bill tips open molluscs by prising them apart or hammering through the shell, whereas pointed-bill birds dig up worms. Much of this is due to the wear resulting from feeding on the prey, individual birds specialise in one technique or the other which they learn from their parents. Bill length shows clinal variation with an increase from west to east, the subspecies longipes has distinctly brownish upperparts and the nasal groove extends more than halfway along the bill. In the subspecies ostralegus the nasal groove stops short of the half-way mark, the osculans subspecies lacks white on the shafts of the outer 2–3 primaries and has no white on the outer webs of the outer five primaries. This is a species over most of its range. The European population breeds mainly in northern Europe, but in winter the birds can be found in north Africa, similar movements are shown by the Asian populations. The birds are gregarious outside the breeding season. The nest is a scrape on pebbles, on the coast or on inland gravelly islands. Both eggs and chicks are highly cryptic, because of its large numbers and readily identified behaviour, the oystercatcher is an important indicator species for the health of the ecosystems where it congregates. Extensive long-term studies have been carried out on its behaviour, in northern Germany, in the Netherlands
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Black oystercatcher
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The black oystercatcher is a conspicuous black bird found on the shoreline of western North America. It ranges from the Aleutian Islands of Alaska to the coast of the Baja California peninsula, the black oystercatcher is the only representative of the oystercatcher family over most of its range, overlapping slightly with the American oystercatcher on the coast of Baja California. Within its range it is most commonly referred to as the oystercatcher, although this name is also used locally for the blackish oystercatcher. Its scientific name is derived by John James Audubon from that of his friend John Bachman, although the species is not considered threatened, its global population size is estimated between 8, 900–11,000 individuals. S. Fish & Wildlife Service focal species for priority conservation action, the black oystercatcher is a large entirely black shorebird, with a long bright red bill and pink legs. It has a yellow iris and a red eye-ring. Its plumage varies slightly from north to south, being further north. The black oystercatcher is restricted in its range, never straying far from shores and it has been suggested that this bird is seen mostly on coastal stretches which have some quieter embayments, such as jetty protected areas. It forages in the zone, feeding on marine invertebrates, particularly molluscs such as mussels, limpets. It will also take crabs, isopods and barnacles and it hunts through the intertidal area, searching for food visually, often so close to the waters edge it has to fly up to avoid crashing surf. It uses its bill to dislodge food and pry shells open. The black oystercatcher is a bird during the nesting season. Some pairs have been recorded staying together for many years, nests are small bowls or depressions close to the shore in which small pebbles and shell fragments are tossed in with a sideward or backard flick of the bill. Around 2 to 3 eggs are laid in this nest, these are very hard, the chicks are capable of leaving the nest after one day, and will stay in the territory for a long time after fledging. The fledged juveniles will stay in the territory until the breeding season. If the parents migrate, that years chicks will migrate with them, blackish oystercatcher Black Oystercatcher, The Birds of North America No 155 B
36.
Raccoon
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The raccoon, sometimes spelled racoon, also known as the common raccoon, North American raccoon, northern raccoon and colloquially as coon, is a medium-sized mammal native to North America. The raccoon is the largest of the family, having a body length of 40 to 70 cm. Its grayish coat mostly consists of dense underfur which insulates it against cold weather, two of the raccoons most distinctive features are its extremely dexterous front paws and its facial mask, which are themes in the mythology of several Native American ethnic groups. Raccoons are noted for their intelligence, with studies showing that they are able to remember the solution to tasks for up to three years, the diet of the omnivorous raccoon, which is usually nocturnal, consists of about 40% invertebrates, 33% plant foods, and 27% vertebrates. As a result of escapes and deliberate introductions in the century, raccoons are now also distributed across mainland Europe, Caucasia. Though previously thought to be solitary, there is now evidence that raccoons engage in social behavior. Home range sizes vary anywhere from 3 hectares for females in cities to 5,000 hectares for males in prairies, after a gestation period of about 65 days, two to five young, known as kits, are born in spring. The kits are subsequently raised by their mother until dispersal in late fall, although captive raccoons have been known to live over 20 years, their life expectancy in the wild is only 1.8 to 3.1 years. In many areas, hunting and vehicular injury are the two most common causes of death, the word raccoon was adopted into English from the native Powhatan term, as used in the Virginia Colony. It was recorded on Captain John Smiths list of Powhatan words as aroughcun and it has also been identified as a Proto-Algonquian root *ahrah-koon-em, meaning one who rubs, scrubs and scratches with its hands. Similarly, Spanish colonists adopted the Spanish word mapache from the Nahuatl mapachitli of the Aztecs, in French and European Portuguese, the washing behavior is combined with these languages term for rat, yielding, respectively, raton laveur and ratão-lavadeiro. The colloquial abbreviation coon is used in words like coonskin for fur clothing and in phrases like old coon as a self-designation of trappers. In the 1830s, the U. S. Whig Party used the raccoon as an emblem, causing them to be known as coons by their political opponents. Soon after that it became an ethnic slur, especially in use between 1880 and 1920, and the term is considered offensive. In 1780, Gottlieb Conrad Christian Storr placed the raccoon in its own genus Procyon and it is also possible that Storr had its nocturnal lifestyle in mind and chose the star Procyon as eponym for the species. Based on fossil evidence from France and Germany, the first known members of the family Procyonidae lived in Europe in the late Oligocene about 25 million years ago. Similar tooth and skull structures suggest procyonids and weasels share a common ancestor, after the then-existing species crossed the Bering Strait at least six million years later in the early Miocene, the center of its distribution was probably in Central America. Coatis and raccoons have been considered to share common descent from a species in the genus Paranasua present between 5.2 and 6.0 million years ago
37.
Skunk
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Skunks are mammals known for their ability to spray a liquid with a strong odor. Different species of skunk vary in appearance from black-and-white to brown or cream colored, 1630s, squunck, from a southern New England Algonquian language seganku, from Proto-Algonquian */šeka, kwa/, from */šek-/ to urinate + */-a, kw/ fox. Skunk has historic use as an insult, attested from 1841, skunk cabbage is attested from 1751, earlier skunkweed. In 1634, a skunk was described in the Jesuit Relations, The other is a low animal, I mention it here, not on account of its excellence, but to make of it a symbol of sin. I have seen three or four of them and it has black fur, quite beautiful and shining, and has upon its back two perfectly white stripes, which join near the neck and tail, making an oval which adds greatly to their grace. The tail is bushy and well furnished with hair, like the tail of a Fox and it is more white than black, and, at the first glance, you would say, especially when it walks, that it ought to be called Jupiters little dog. But it is so stinking, and casts so foul an odor, no sewer ever smelled so bad. I would not have believed it if I had not smelled it myself, I believe the sin smelled by Saint Catherine de Sienne must have had the same vile odor. Skunk species vary in size from about 15.6 to 37 in long and they have moderately elongated bodies with relatively short, well-muscled legs and long front claws for digging. Although the most common fur color is black and white, some skunks are brown or grey, all skunks are striped, even from birth. They may have a thick stripe across back and tail. Some also have stripes on their legs, skunks are omnivorous, eating both plant and animal material and changing their diets as the seasons change. They eat insects and larvae, earthworms, grubs, rodents, lizards, salamanders, frogs, snakes, birds, moles and they also commonly eat berries, roots, leaves, grasses, fungi and nuts. In settled areas, skunks also seek garbage left by humans, less often, skunks may be found acting as scavengers, eating bird and rodent carcasses left by cats or other animals. Pet owners, particularly those of cats, may experience a skunk finding its way into a garage or basement where pet food is kept, skunks commonly dig holes in lawns in search of grubs and worms. Skunks are one of the predators of the honeybee, relying on their thick fur to protect them from stings. The skunk scratches at the front of the beehive and eats the guard bees that come out to investigate, mother skunks are known to teach this behavior to their young. Skunks are crepuscular and solitary animals when not breeding, though in the parts of their range
38.
Mink
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Mink are dark-colored, semiaquatic, carnivorous mammals of the family Mustelidae, which also includes weasels, otters and ferrets. There are two extant species referred to as mink, the American mink and the European mink, the extinct sea mink is related to the American mink, but was much larger. The American mink is larger and more adaptable than the European mink, Due to variations in size, an individual mink usually cannot be determined as European or American with certainty without looking at the skeleton. There is one exception to rule, all European minks have a large white patch on their upper lip. Thus, any mink with no such patch is certainly of the American variety, taxonomically, both American and European minks used to be placed in the same genus Mustela, but most recently the American mink has been reclassified as belonging to its own genus Neovison. Its treatment has also been a focus of animal rights and animal welfare activism, American mink have found their way into the wild in Europe and South America, after being released from mink farms by animal rights activists or otherwise escaping from captivity. In the UK, under the Wildlife & Countryside Act 1981, any live mink caught in traps must be humanely killed. American mink are believed by some to have contributed to the decline of the less hardy European mink through competition, trapping is used to control or eliminate feral American mink populations. Mink oil is used in medical products and cosmetics, as well as to treat, preserve. European mink Mustela lutreola American mink Neovison vison Sea mink Neovison macrodon The male weighs about 1 kg and is about 62 cm in length, Farm bred males can reach 3.2 kg. The female weighs about 600 g and reaches a length of about 51 cm, the sizes above do not include the tail which can be from 12.8 centimetres to 22.8 centimetres. A minks rich glossy coat in its state is brown and looks silky, but farm-bred mink can vary from white to almost black. Their pelage is deep, rich brown, with or without white spots on the underparts, the breeding season lasts April to May. Mink show the phenomenon of delayed implantation. Although the true gestation period is 39 days, the embryo may stop developing for a variable period, between 45 and 52 days is normal. There is only one litter per year and they may have between six and ten cubs or kittens per litter. Mink are kept in captivity primarily for the production of their fur and they are often kept in battery cages and frequently exhibit stereotypies. These abnormal, repetitive behaviours increase near their feeding time, specifically pacing and cage biting, stereotypies have also been noted to increase during human presence
39.
Otter
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Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic or marine, with diets based on fish, Lutrinae is a branch of the weasel family Mustelidae, which also includes badgers, honey badgers, martens, minks, polecats, and wolverines. The word otter derives from the Old English word otor or oter and this, and cognate words in other Indo-European languages, ultimately stem from the Proto-Indo-European language root *wódr̥, which also gave rise to the English word water. An otters den is called a holt or couch, male otters are called dogs or boars, females are called bitches or sows, and their offspring are called pups. The collective nouns for otters are bevy, family, lodge, romp or, the feces of otters are typically identified by their distinctive aroma, the smell of which has been described as ranging from freshly mown hay to putrefied fish, these are known as spraints. The gestation period in otters is about 60 to 86 days, the newborn pup is cared for by the bitch, dog and older offspring. Bitch otters reach sexual maturity at two years of age and males at approximately three years. The holt is built under tree roots or a rocky cairn and it is lined with moss and grass. After one month, the pup can leave the holt and after two months, it is able to swim, the pup lives with its family for approximately one year. Otters live up to 16 years, they are by nature playful and its usual source of food is fish, and further downriver, eels, but it may sample frogs and birds. Otters have long, slim bodies and relatively short limbs and their most striking anatomical features are the powerful webbed feet used to swim, and their seal-like abilities holding breath underwater. Most have sharp claws on their feet and all except the sea otter have long, the 13 species range in adult size from 0.6 to 1.8 m in length and 1 to 45 kg in weight. The Oriental small-clawed otter is the smallest otter species and the giant otter and they have very soft, insulated underfur, which is protected by an outer layer of long guard hairs. This traps a layer of air which keeps them dry, warm, several otter species live in cold waters and have high metabolic rates to help keep them warm. European otters must eat 15% of their weight each day. In water as warm as 10 °C, an otter needs to catch 100 g of fish per hour to survive, most species hunt for three to five hours each day and nursing mothers up to eight hours each day. For most otters, fish is the staple of their diet and this is often supplemented by frogs, crayfish and crabs. Some otters are expert at opening shellfish, and others feed on available small mammals or birds
40.
Gull
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Gulls, often referred to as seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and only related to auks, skimmers. Until the 21st century, most gulls were placed in the genus Larus, an older name for gulls is mew, cognate with German Möwe, Danish måge, Dutch meeuw, and French mouette, this term can still be found in certain regional dialects. Gulls are typically medium to large birds, usually grey or white and they typically have harsh wailing or squawking calls, stout, longish bills, and webbed feet. Most gulls, particularly Larus species, are ground-nesting carnivores, which take food or scavenge opportunistically. Live food often includes crabs and small fish, gulls have unhinging jaws which allow them to consume large prey. Apart from the kittiwakes, gulls are typically coastal or inland species, the large species take up to four years to attain full adult plumage, but two years is typical for small gulls. Large white-headed gulls are typically long-lived birds, with an age of 49 years recorded for the herring gull. Gulls nest in large, densely packed noisy colonies and they lay two or three speckled eggs in nests composed of vegetation. The young are precocial, being born with dark mottled down, gulls—the larger species in particular—are resourceful, inquisitive and intelligent birds, demonstrating complex methods of communication and a highly developed social structure. For example, many gull colonies display mobbing behaviour, attacking and harassing would-be predators, certain species have exhibited tool use behaviour, using pieces of bread as bait with which to catch goldfish, for example. Many species of gulls have learned to coexist successfully with humans and have thrived in human habitats, others rely on kleptoparasitism to get their food. Gulls have been observed preying on live whales, landing on the whale as it surfaces to peck out pieces of flesh. Gulls range in size from the gull, at 120 g and 29 cm, to the great black-backed gull. They are generally uniform in shape, with bodies, long wings. The tails of all but three species are rounded, the exceptions being Sabines gull and swallow-tailed gulls, which have forked tails, and Rosss gull, gulls have moderately long legs, especially when compared to the similar terns, with fully webbed feet. The bill is heavy and slightly hooked, with the larger species having stouter bills than the smaller species. The bill colour is yellow with a red spot for the larger white-headed species and red
41.
Crow
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A crow is a bird of the genus Corvus. The term crow is used both as part of the name of many species, and collectively for all of Corvus
42.
Fox
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Foxes are small-to-medium-sized, omnivorous mammals belonging to several genera of the family Canidae. Foxes are slightly smaller than a domestic dog, with a flattened skull, upright triangular ears, a pointed, slightly upturned snout. Twelve species belong to the group of Vulpes genus of true foxes. Foxes live on every continent except Antarctica, by far the most common and widespread species of fox is the red fox with about 47 recognized subspecies. The global distribution of foxes, together with their reputation for cunning, has contributed to their prominence in popular culture and folklore in many societies around the world. The hunting of foxes with packs of hounds, long an established pursuit in Europe, the word fox comes from Old English, which derived from Proto-Germanic *fuhsaz. This in turn derives from Proto-Indo-European *puḱ-, meaning ’thick-haired, tail’. Male foxes are known as dogs, tods or reynards, females as vixens, a group of foxes is referred to as a skulk, leash, or earth. Foxes are generally smaller than members of the family Canidae such as wolves, jackals. For example, in the largest species, the red fox, males weigh on average between 4.1 and 8.7 kg, while the smallest species, the fennec fox, weighs just 0.7 to 1.6 kg. Fox-like features typically include a face, pointed ears, an elongated rostrum. Foxes are digitigrade, and thus, walk on their toes, unlike their dog relatives, foxes have partially retractable claws. Fox vibrissae, or whiskers, are black, the whiskers on the muzzle, mystaciae vibrissae, average 100-110mm long, while the whiskers everywhere else on the head average to be shorter in length. Whiskers are also on the forelimbs and average 40mm long, pointing downward and backward, other physical characteristics vary according to habitat and adaptive significance. Fox species differ in fur color, length, and density, coat colors range from pearly white to black and white to black flecked with white or grey on the underside. Fennec foxes, for example, have ears and short fur to aid in keeping the body cool. Arctic foxes, on the hand, have tiny ears and short limbs as well as thick, insulating fur. Red foxes, by contrast, have a typical auburn pelt, a foxs coat color and texture may vary due to the change in seasons, fox pelts are richer and denser in the colder months and lighter in the warmer months
43.
Stoat
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Originally from Eurasia, it crossed into North America some half million years ago, where it naturalized and joined the notably larger closely related native long-tailed weasel. The name ermine is often, but not always, used for the stoat in its white winter coat. In the late 19th century, stoats were introduced into New Zealand to control rabbits, the stoat is classed by the IUCN as least concern, due to its wide circumpolar distribution, and because it does not face any significant threat to its survival. It was nominated as one of the worlds top 100 worst invaders, Ermine luxury fur was used in the 15th century by Catholic monarchs, who sometimes used it as the mozzetta cape. It was also used in capes on images such as the Infant Jesus of Prague, the root word for stoat is likely either the Dutch word stout or the Gothic word stautan. This seems to come from the Lithuanian word šarmu, in Ireland, the stoat is referred to as a weasel, while in North America it is called a short-tailed weasel. A male stoat is called a dog, hob, or jack, the collective noun for stoats is either gang or pack. The stoat is the product of a process begun 5–7 million years ago, the stoats ancestors were larger than the current form, and underwent a reduction in size as they exploited the new food source. The stoat first arose in Eurasia, shortly after the long-tailed weasel arose as its image in North America 2 million years ago. The stoat thrived during the Ice Age, as its size and long body allowed it to easily operate beneath snow. The stoat and the long-tailed weasel remained separated until half a million years ago, combined phylogenetic analyses indicate the stoats closest living relative is the mountain weasel, though it is also closely related to the least weasel and long-tailed weasel. Its next closest relatives are the New World Colombian weasel and the Amazon weasel, as of 2005,37 subspecies are recognized. The stoat has a neck, the head being set exceptionally far in front of the shoulders. The trunk is cylindrical, and does not bulge at the abdomen. The greatest circumference of body is more than half its length. The skull, although similar to that of the least weasel, is relatively longer. The projections of the skull and teeth are developed. The eyes are round, black and protrude slightly, the whiskers are brown or white in colour, and very long
44.
Long-tailed weasel
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It is distinct from the short-tailed weasel, also known as a stoat, a close relation which originated in Eurasia and crossed into North America some half million years ago. The long-tailed weasels ancestors were larger than the current form, the long-tailed weasel arose in North America 2 million years ago, shortly before the stoat evolved as its mirror image in Eurasia. The species thrived during the Ice Age, as its size and long body allowed it to easily operate beneath snow. The long-tailed weasel and the stoat remained separated until half a million years ago, however, unlike the latter species, the long-tailed weasel never crossed the land bridge, and did not spread into Eurasia. The long-tailed weasel is one of the members of the genus Mustela in North America. It adds that I n most populations, females are 10–15% smaller than males, thus making them about the size as large male stoats. A third states they range from 11 to 22 inches in length, with the tail measuring an additional 3 to 6 inches and it maintains the long-tailed weasel weighs between 3 and 9 ounces with males being about twice as large as the females. The eyes are black in daylight, but glow bright green when caught in a spotlight at night. The dorsal fur is brown in summer, while the underparts are whitish, the tail has a distinct black tip. Long-tailed weasels in Florida and the southwestern US may have markings of a white or yellowish colour. In northern areas in winter, the long-tailed weasels fur becomes white, sometimes with yellow tints, the long-tailed weasel moults twice annually, once in autumn and once in spring. Each moult takes about 3–4 weeks and is governed by day length, unlike the stoat, whose soles are thickly furred all year, the long-tailed weasels soles are naked in summer. The long-tailed weasel has well-developed anal scent glands, which produce a strong, the long-tailed weasel mates in July–August, with implantation of the fertilized egg on the uterine wall being delayed until about March. Litter size generally consists of 5–8 kits, which are born in April–May, the kits are born partially naked, blind and weighing 3 grams, about the same weight of a hummingbird. The long-tailed weasels growth rate is rapid, as by the age of three weeks, the kits are well furred, can crawl outside the nest and eat meat, at this time, the kits weigh 21–27 grams. At five weeks of age, the eyes open. Weaning begins at this stage, with the kits emerging from the nest, the kits are fully grown by autumn, at which time the family disbands. The females are able to breed at 3–4 months of age, the long-tailed weasel dens in ground burrows, under stumps or beneath rock piles
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Dasypeltis
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Dasypeltis is a genus of colubrid snakes. It is one of only two groups of snakes known to have adapted to feed exclusively on eggs. They are non-venomous and found throughout the continent of Africa, primarily in forested or wooded habitats that are home to numerous species of birds. Individuals in a specific locality tend to share similar color and pattern and they vary in size greatly, from 30–100 cm in length. They are agile climbers, and have a sense of smell to tell whether an egg is rotten or too far developed to be comfortable to eat. Then the snake carefully squeezes every last bit of out of the inside of the egg. They are remarkably efficient, and waste very little of the contents of an egg, a sequence of a Montane Egg-eating Snake, Dasypeltis atra consuming a quail egg. Dasypeltis species are available in the exotic pet trade. Most egg-eating snakes never get enough to consume typical chicken eggs, so smaller ones must be provided. Once a reliable source of food is obtained, Dasypeltis make easy, captive breeding is virtually unknown, so almost all specimens available are wild caught. Many owners have resorted to feeding their Dasypeltis because the animal seems not to be eating. However, evidence has shown that, like large constrictors, these snakes may go for long periods without eating after a large meal. As long as the snake is behaving normally and does not appear to be in physical distress, when a specimen seems to be off its food, offering it eggs approximately monthly is appropriate. If the snake does not eat but continues to drink, is active, and sheds, then it does not need to be force fed
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Indian egg-eating snake
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The Indian egg-eating snake or Indian egg-eater is a rare species of egg-eating snake found in the Indian subcontinent. It is also called Westermanns snake, reflecting its scientific name, the snake belongs to the monotypic genus Elachistodon. The Indian egg-eating snake is found in Bangladesh, India, recent discoveries of the species come from Maharashtra, Gujarat, Punjab, Madhya Pradesh and Telangana. This species is brown to black, with bluish white flecks posteriorly. The head is brown with a black arrow mark, the ventrals are white with brown dots. Adults may attain a length of 78 cm, with a tail 11 cm long. A nocturnal, terrestrial species that shows remarkable dexterity in scaling vegetation, when provoked, it raises the anterior portion of the body, forming ‘S’ shaped coils as a defensive strategy. Elachistodon westermanni exclusively feeds on eggs that lack embryonic growth. It has special adaptations such as a vertebral hypapophysis, a projection of the backbone, the only other snakes that share these egg-eating adaptations are in the genus Dasypeltis found in Africa. Genus information Elachistodon westermanni at the Reptarium. cz Reptile Database
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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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Cowbird
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Cowbirds are birds belonging to the genus Molothrus in the family Icteridae. They are of New World origin, the non-brood parasitic baywing was formerly placed in this genus, it is now classified as Agelaioides badius. These birds feed on insects, including the numbers that may be stirred up by cattle. In order for the birds to remain mobile and stay with the herd, the cowbird will watch for when its host lays eggs, and when the nest is left unattended, the female will come in and lay its own eggs. The female cowbird may continue to observe the nest after laying her eggs, if the cowbird egg is removed, the female cowbird may destroy the hosts eggs
