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Winter White Dwarf Hamster
The winter white dwarf hamster (''Phodopus sungorus''), also known as the Russian dwarf hamster, Djungarian hamster, Dzungarian hamster, striped dwarf hamster, Siberian hamster, or Siberian dwarf hamster, is one of three species of hamster in the genus '' Phodopus''. It is ball-shaped and typically half the size of the Syrian hamster, so is called a dwarf hamster along with all ''Phodopus'' species. Features of the winter white hamster include a typically thick, dark grey dorsal stripe and furry feet. As winter approaches and the days shorten, the winter white dwarf hamster's dark fur is almost entirely replaced with white fur. In captivity, this does not usually happen as animals maintained as pets are generally housed indoors and exposed to artificial light that prevents the recognition of short winter daylengths. In the wild, they originate from the wheat fields of Kazakhstan, the meadows of Mongolia and Siberia, and the birch stands of Manchuria. Winter white dwarf hamsters a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peter Simon Pallas
Peter Simon Pallas Fellow of the Royal Society, FRS FRSE (22 September 1741 – 8 September 1811) was a Prussia, Prussian zoologist, botanist, Ethnography, ethnographer, Exploration, explorer, Geography, geographer, Geology, geologist, Natural history, natural historian, and Taxonomy, taxonomist. He studied natural sciences at various universities in Germany in the early modern period, early modern Germany and worked primarily in the Russian Empire between 1767 and 1810. Life and work Peter Simon Pallas was born in Berlin, Kingdom of Prussia, the son of Professor of Surgery Simon Pallas. He studied with private tutors and took an interest in natural history, later attending the University of Halle and the University of Göttingen. In 1760, he moved to the University of Leiden and passed his doctor's degree at the age of 19. Pallas travelled throughout the Dutch Republic and to London, improving his medical and surgical knowledge. He then settled at The Hague, and his new ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subspecies
In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morphology), but that can successfully interbreed. Not all species have subspecies, but for those that do there must be at least two. Subspecies is abbreviated as subsp. or ssp. and the singular and plural forms are the same ("the subspecies is" or "the subspecies are"). In zoology, under the International Code of Zoological Nomenclature, the subspecies is the only taxonomic rank below that of species that can receive a name. In botany and mycology, under the International Code of Nomenclature for algae, fungi, and plants, other infraspecific name, infraspecific ranks, such as variety (botany), variety, may be named. In bacteriology and virology, under standard International Code of Nomenclature of Prokaryotes, bacterial nomenclature and virus clas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pigmentation
A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly insoluble and chemically unreactive in water or another medium; in contrast, dyes are colored substances which are soluble or go into solution at some stage in their use. Dyes are often organic compounds whereas pigments are often inorganic. Pigments of prehistoric and historic value include ochre, charcoal, and lapis lazuli. Economic impact In 2006, around 7.4 million tons of inorganic, organic, and special pigments were marketed worldwide. According to an April 2018 report by ''Bloomberg Businessweek'', the estimated value of the pigment industry globally is $30 billion. The value of titanium dioxide – used to enhance the white brightness of many products – was placed at $13.2 billion per year, while the color Ferrari red is valued at $300 million each year. Physical principles Like all materials, the color of pigments arises because they absor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moulting
In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is a process by which an animal casts off parts of its body to serve some beneficial purpose, either at specific times of the year, or at specific points in its life cycle. In medieval times, it was also known as "mewing" (from the French verb "muer", to moult), a term that lives on in the name of Britain's Royal Mews where the King's hawks used to be kept during moulting time before becoming horse stables after Tudor times. Moulting can involve shedding the Epidermis (skin), epidermis (skin), pelage (hair, feathers, fur, wool), or other external layer. In some groups, other body parts may be shed, for example, the entire exoskeleton in arthropods, including the wings in some insects. Examples In birds In birds, moulting is the periodic replacement of feathers by shedding old feathers while producing new ones. Feathers are dead struct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Density
Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be used: \rho = \frac, where ''ρ'' is the density, ''m'' is the mass, and ''V'' is the volume. In some cases (for instance, in the United States oil and gas industry), density is loosely defined as its weight per unit volume, although this is scientifically inaccurate this quantity is more specifically called specific weight. For a pure substance, the density is equal to its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity and packaging. Osmium is the densest known element at standard conditions for temperature and pressure. To simplify comparisons of density across different systems of units, it is sometimes replaced by the dimensionless quantity "relative den ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whisker
Whiskers, also known as vibrissae (; vibrissa; ) are a type of stiff, functional hair used by most therian mammals to sense their environment. These hairs are finely specialised for this purpose, whereas other types of hair are coarser as tactile sensors. Although whiskers are specifically those found around the face, vibrissae are known to grow in clusters at various places around the body. Most mammals have them, including all non-human primates and especially nocturnal mammals. Monotremes, however, lack them. Whiskers are sensitive tactile hairs that aid navigation, locomotion, exploration, hunting, social touch and perform other functions. This article is primarily about the specialised sensing hairs of mammals, but some birds, fish, insects, crustaceans and other arthropods are known to have similar structures also used to sense the environment. Etymology Vibrissae (from Latin 'to vibrate') from the characteristic motion seen in a small rodent that is otherwise sit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tint
In color theory, a tint is a mixture of a color with white, which increases lightness, while a shade is a mixture with black, which increases darkness. A tone is produced either by mixing a color with gray, or by both tinting and shading. Mixing a color with any neutral color (black, gray, and white) reduces the chroma, or colorfulness, while the perceived hue can be affected slightly (see Abney effect and Bezold-Brücke shift). In the graphic arts, especially printmaking and drawing, "tone" has a different meaning, referring to areas of continuous color, produced by various means, as opposed to the linear marks made by an engraved or drawn line. In common language, the term ''shade'' can be generalized to encompass any varieties of a particular color, whether technically they are shades, tints, tones, or slightly different hues. Meanwhile, the term ''tint'' can be generalized to refer to any lighter or darker variation of a color (e.g. " tinted windows"). When ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Captivity (animal)
Animal captivity is the confinement of domestic and wild animals. More specifically, animals that are held by humans and prevented from escaping are said to be in captivity. The term animal captivity is usually applied to wild animals that are held in confinement, but this term may also be used generally to describe the keeping of domesticated animals such as livestock or pets. This may include, for example, animals in farms, private homes, zoos, aquariums, public aquariums and laboratories. Animal captivity may be categorized according to the particular motives, objectives, and conditions of the confinement. History All throughout history, domestic animals like pets and livestock were kept in captivity and tended by humans. However, pets and livestock were not the only animals to be put in captivity and receive human care because wild animals had this as well. Despite the fact that wild animals have been harbored by humans for thousands of years, this captivity has not always ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Body Weight
Human body weight is a person's mass or weight. Strictly speaking, body weight is the measurement of mass without items located on the person. Practically though, body weight may be measured with clothes on, but without shoes or heavy accessories such as mobile phones and wallets, and using manual or digital weighing scales. Excess or reduced body weight is regarded as an indicator of determining a person's health, with body volume measurement providing an extra dimension by calculating the distribution of body weight. Average adult human weight varies by continent, from about in Asia and Africa to about in North America, with men on average weighing more than women. Estimation in children There are a number of methods to estimate weight in children for circumstances (such as emergencies) when actual weight cannot be measured. Most involve a parent or health care provider guessing the child's weight through weight-estimation formulas. These formulas base their findings on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winter White Hamster Merle Sapphire
Winter is the coldest and darkest season of the year in temperate and polar climates. It occurs after autumn and before spring. The tilt of Earth's axis causes seasons; winter occurs when a hemisphere is oriented away from the Sun. Different cultures define different dates as the start of winter, and some use a definition based on weather. When it is winter in the Northern Hemisphere, it is summer in the Southern Hemisphere, and vice versa. Winter typically brings precipitation that, depending on a region's climate, is mainly rain or snow. The moment of winter solstice is when the Sun's elevation with respect to the North or South Pole is at its most negative value; that is, the Sun is at its farthest below the horizon as measured from the pole. The day on which this occurs has the shortest day and the longest night, with day length increasing and night length decreasing as the season progresses after the solstice. The earliest sunset and latest sunrise dates outside th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
