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Beaver
Beavers are large, semiaquatic rodents in the genus ''Castor'' native to the temperate Northern Hemisphere. There are two extant species: the North American beaver (''Castor canadensis'') and the Eurasian beaver (''C. fiber''). Beavers are the second-largest living rodents after the capybaras. They have stout bodies with large heads, long chisel-like incisors, brown or gray fur, hand-like front feet, webbed back feet and flat, scaly tails. The two species differ in the shape of the skull and tail and fur color. Beavers can be found in a number of freshwater habitats, such as rivers, streams, lakes and ponds. They are herbivorous, consuming tree bark, aquatic plants, grasses and sedges. Beavers build dams and lodges using tree branches, vegetation, rocks and mud; they chew down trees for building material. Dams impound water and lodges serve as shelters. Their infrastructure creates wetlands used by many other species, and because of their effect on other organisms in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North American Beaver
The North American beaver (''Castor canadensis'') is one of two extant beaver species, along with the Eurasian beaver (''Castor fiber''). It is native to North America and introduced in South America ( Patagonia) and Europe (primarily Finland and Karelia). In Canada and the United States, the species is often referred to simply as "beaver", though this causes some confusion because another distantly related rodent, '' Aplodontia rufa'', is often called the "mountain beaver". Other vernacular names, including American beaver and Canadian beaver, distinguish this species from the other extant beaver species, '' Castor fiber'', which is native to Eurasia. The North American beaver is one of the official national wildlife of Canada symbols and is the official state mammal of Oregon and New York. Taxonomy Evolution The first fossil records of beaver are 10 to 12 million years old in Germany, and they are thought to have migrated to North America across the Bering Strait. The ol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eurasian Beaver
The Eurasian beaver (''Castor fiber'') or European beaver is a beaver species that was once widespread in Eurasia, but was hunted to near-extinction for both its fur and castoreum. At the turn of the 20th century, only about 1,200 beavers survived in eight relict populations in Europe and Asia. It has been reintroduced to much of its former range, and now occurs from Spain, Central Europe, Great Britain and Scandinavia to a few regions in China and Mongolia. It is listed as least concern on the IUCN Red List, as it recovered well in most of Europe. It is extirpated in Portugal, Moldova, and Turkey. Taxonomy ''Castor fiber'' was the scientific name used by Carl Linnaeus in 1758, who described the beaver in his work ''Systema Naturae''. Between 1792 and 1997, several Eurasian beaver zoological specimens were described and proposed as subspecies, including: *''C. f. albus'' and ''C. f. solitarius'' by Robert Kerr in 1792 *''C. f. fulvus'' and ''C. f. variegatus'' by Johann Matth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Castor Fiber
The Eurasian beaver (''Castor fiber'') or European beaver is a beaver species that was once widespread in Eurasia, but was hunted to near-extinction for both its fur and castoreum. At the turn of the 20th century, only about 1,200 beavers survived in eight relict populations in Europe and Asia. It has been reintroduced to much of its former range, and now occurs from Spain, Central Europe, Great Britain and Scandinavia to a few regions in China and Mongolia. It is listed as least concern on the IUCN Red List, as it recovered well in most of Europe. It is extirpated in Portugal, Moldova, and Turkey. Taxonomy ''Castor fiber'' was the scientific name used by Carl Linnaeus in 1758, who described the beaver in his work ''Systema Naturae''. Between 1792 and 1997, several Eurasian beaver zoological specimens were described and proposed as subspecies, including: *''C. f. albus'' and ''C. f. solitarius'' by Robert Kerr in 1792 *''C. f. fulvus'' and ''C. f. variegatus'' by Johann Matth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beaver Dam
A beaver dam or beaver impoundment is a dam built by beavers to create a pond which protects against predators such as coyotes, wolves and bears, and holds their food during winter. These structures modify the natural environment in such a way that the overall ecosystem builds upon the change, making beavers a keystone species and ecosystem engineers. They build prolifically at night, carrying mud and stones with their forepaws and timber between their teeth. Construction A minimum water level of is required to keep the underwater entrance to beaver lodges from being blocked by ice during the winter. In lakes, rivers and large streams with deep enough water, beavers may not even need to build dams, and instead simply live in bank burrows and lodges. If the water is not deep enough to keep beavers safe from predators and their lodge entrances ice-free, beavers build dams.Beavers start construction by diverting the stream to lessen the water's flow pressure. Branches and logs are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodents
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for New Zealand, Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity. Rodents are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat, including human-made environments. Species can be arboreal, fossorial (burrowing), saltatorial/richochetal (leaping on their hind legs), or semiaquatic. However, all rodents share several morphological features, including having only a single upper and lower pair of ever-growing incisors. Well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, and hamsters. Rabbits, hares, and pikas, who ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fur Trade
The fur trade is a worldwide industry dealing in the acquisition and sale of animal fur. Since the establishment of a world fur market in the early modern period, furs of boreal ecosystem, boreal, polar and cold temperate mammalian animals have been the most valued. Historically the trade stimulated the exploration and colonization of Siberia, northern North America, and the South Shetland Islands, South Shetland and South Sandwich Islands. Today the importance of the fur trade has diminished; it is based on pelts produced at fur farms and regulated fur-bearer trapping, but has become controversial. Animal rights organizations oppose the fur trade, citing that animals are brutally killed and sometimes skinned alive. Fur has been replaced in some clothing by synthetic fiber, synthetic imitations, for example, as in ruffs on hoods of parkas. Continental fur trade Russian fur trade Before the European colonization of the Americas, Russia was a major supplier of fur pelts to W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Castoreum
Castoreum is a yellowish exudate from the castor sacs of mature beavers. Beavers use castoreum in combination with urine to scent mark their territory. Both beaver sexes have a pair of castor sacs and a pair of anal glands, located in two cavities under the skin between the pelvis and the base of the tail. The castor sacs are not true glands (endocrine or exocrine) on a cellular level, hence references to these structures as preputial glands, castor glands, or scent glands are misnomers. It is used as a tincture in some perfumesInternational Perfume Museum, Grasse, France, Website: and was sometimes used as a food additive in the early 1900s. The sacs brought per ounce when auctioned at the May–June 2016 North American Fur Auction. Chemical composition At least 24 compounds are known constituents of beaver castoreum. Several of these have pheromonal activity, of which the phenols 4-ethylphenol and catechol and the ketones acetophenone and 3-hydroxyacetophenone were str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keystone Species
A keystone species is a species which has a disproportionately large effect on its natural environment relative to its abundance, a concept introduced in 1969 by the zoologist Robert T. Paine. Keystone species play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and numbers of various other species in the community. Without keystone species, the ecosystem would be dramatically different or cease to exist altogether. Some keystone species, such as the wolf, are also apex predators. The role that a keystone species plays in its ecosystem is analogous to the role of a keystone in an arch. While the keystone is under the least pressure of any of the stones in an arch, the arch still collapses without it. Similarly, an ecosystem may experience a dramatic shift if a keystone species is removed, even though that species was a small part of the ecosystem by measures of biomas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Castor Californicus
''Castor californicus'' is an extinct species of beaver that lived in western North America from the end of the Miocene to the early Pleistocene. The species was similar to but larger than the extant North American beaver, '' C. canadensis''. References Further reading * Prehistoric beavers Prehistoric mammals of North America Miocene rodents Pleistocene rodents † A dagger, obelisk, or obelus is a typographical mark that usually indicates a footnote if an asterisk has already been used. The symbol is also used to indicate death (of people) or extinction (of species). It is one of the modern descendan ... Taxa named by Vernon Lyman Kellogg Fossil taxa described in 1911 {{paleo-rodent-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Castor Praefiber
Castor most commonly refers to: * Castor (star), a star in the Gemini constellation *Castor, one of the Dioscuri/Gemini twins Castor and Pollux in Greco-Roman mythology Castor or CASTOR may also refer to: Science and technology * Castor (rocket stage), a family of solid-fuel rocket stages * Castor (software), data binding framework for Java * ''CASTOR'' (nuclear waste), cask for storage and transport of radioactive material * ''CASTOR'' experiment, "Centauro and Strange Object Research" at CERN * CASTOR (spacecraft), proposed space telescope * Castor sugar, fine sugar * Caster (or Castor), an undriven wheel * Caster (or Castor) angle, relevant to a steered wheel Biology * Castor oil plant, plant from which castor bean grows **Castor oil, oil of the castor bean **Castor wax, produced from castor oil *''Castor'', a genus name of the beaver **Castoreum, natural scent derived from the beaver People Given name Ancient * Castor of Rhodes, Greek grammarian and rhetorician *Drusus the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Castor Neglectus
Castor most commonly refers to: * Castor (star), a star in the Gemini constellation *Castor, one of the Dioscuri/Gemini twins Castor and Pollux in Greco-Roman mythology Castor or CASTOR may also refer to: Science and technology * Castor (rocket stage), a family of solid-fuel rocket stages * Castor (software), data binding framework for Java * ''CASTOR'' (nuclear waste), cask for storage and transport of radioactive material * ''CASTOR'' experiment, "Centauro and Strange Object Research" at CERN * CASTOR (spacecraft), proposed space telescope * Castor sugar, fine sugar * Caster (or Castor), an undriven wheel * Caster (or Castor) angle, relevant to a steered wheel Biology * Castor oil plant, plant from which castor bean grows **Castor oil, oil of the castor bean **Castor wax, produced from castor oil *''Castor'', a genus name of the beaver **Castoreum, natural scent derived from the beaver People Given name Ancient * Castor of Rhodes, Greek grammarian and rhetorician *Drusus the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wetland
A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (Anoxic waters, anoxic) processes prevailing, especially in the soils. The primary factor that distinguishes wetlands from terrestrial land forms or Body of water, water bodies is the characteristic vegetation of aquatic plants, adapted to the unique anoxic hydric soils. Wetlands are considered among the most biologically diverse of all ecosystems, serving as home to a wide range of plant and animal species. Methods for assessing wetland functions, wetland ecological health, and general wetland condition have been developed for many regions of the world. These methods have contributed to wetland conservation partly by raising public awareness of the functions some wetlands provide. Wetlands occur naturally on every continent. The water in wetlands is either freshwater, brackish or seawater, saltwate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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