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Kaibab Squirrel
The Kaibab squirrel (''Sciurus aberti kaibabensis'') is a tassel-eared squirrel that lives in the Kaibab Plateau in the Southwest United States, in an area of . The squirrel's habitat is confined entirely to the ponderosa pine forests of the North Rim of Grand Canyon National Park and the northern section of Kaibab National Forest around the town of Jacob Lake, Arizona. This squirrel is not found anywhere else in the world. In 1965, of Kaibab squirrel habitat within Grand Canyon National Park and Kaibab National Forest were declared the Kaibab Squirrel National Natural Landmark. Description Kaibab squirrels usually have a black belly (which is sometimes gray), white tail, tufted ears and chestnut brown head. The tufts on the ears grow longer with age and may extend above the ears in the winter, and may not be visible in the summer. Ecology The Kaibab squirrel lives in ponderosa pine forests, where it builds its nest out of twigs and pine needles. Kaibab squirrels, ponderosa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clinton Hart Merriam
Clinton Hart Merriam (December 5, 1855 – March 19, 1942) was an American zoologist, mammalogist, ornithologist, entomologist, ecologist, ethnographer, geographer, naturalist and physician. He was commonly known as the 'father of mammalogy', a branch of zoology referring to the study of mammals. Early life Clinton Hart Merriam was born in New York City in 1855 to Clinton Levi Merriam, a U.S. congressman, and Caroline Hart, a judge's daughter and a graduate of Rutgers Institute. The name Clinton, shared by both father and son, was in honor of New York governor DeWitt Clinton, whom the Merriam family had connections with. To avoid confusion, the younger Merriam went by his first initial combined with his middle name, his mother's maiden name, and thus often appears as C. Hart Merriam in both the literature of his time and thereafter. Although born in New York City, where his parents were staying the winter, the family home and place where Merriam spent his boyhood days was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acorn
The acorn, or oaknut, is the nut of the oaks and their close relatives (genera ''Quercus'' and '' Lithocarpus'', in the family Fagaceae). It usually contains one seed (occasionally two seeds), enclosed in a tough, leathery shell, and borne in a cup-shaped cupule. Acorns are long and on the fat side. Acorns take between 5 and 24 months (depending on the species) to mature; see the list of ''Quercus'' species for details of oak classification, in which acorn morphology and phenology are important factors. Etymology The word ''acorn'' (earlier ''akerne'', and ''acharn'') is related to the Gothic name ''akran'', which had the sense of "fruit of the unenclosed land". The word was applied to the most important forest produce, that of the oak. Chaucer spoke of "achornes of okes" in the 14th century. By degrees, popular etymology connected the word both with "corn" and "oak-horn", and the spelling changed accordingly. The current spelling (emerged 15c.-16c.), derives from asso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural History Of The Grand Canyon
Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are part of nature, human activity is often understood as a separate category from other natural phenomena. The word ''nature'' is borrowed from the Old French ''nature'' and is derived from the Latin word ''natura'', or "essential qualities, innate disposition", and in ancient times, literally meant "birth". In ancient philosophy, ''natura'' is mostly used as the Latin translation of the Greek word '' physis'' (φύσις), which originally related to the intrinsic characteristics of plants, animals, and other features of the world to develop of their own accord. The concept of nature as a whole, the physical universe, is one of several expansions of the original notion; it began with certain core applications of the word φύσις by pre-So ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic Fauna Of Arizona
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammals Of The United States
About 490 species of mammals are recorded in the United States. Unincorporated territories like for example Puerto Rico, Guam or Northern Mariana Islands are not covered. Mammals introduced and extinct in the Holocene except Pleistocene/Holocene boundary are included. According to the IUCN Red List 3 of these species are critically endangered, 20 endangered, 15 vulnerable, 20 near threatened and 4 extinct. Some species are identified as indicated below: *(A) - Accidental *(E) - Extinct *(Ex) - Extirpated (extinct in the US, but exists elsewhere in the world) *(I) - Introduced The following tags are used to highlight each species' conservation status as assessed by the International Union for Conservation of Nature: (v. 2013.2, the data are current as of March 5, 2014) and the Endangered Species Act: (the data are current as of March 28, 2014) Subclass: Theria Infraclass: Metatheria Order: Didelphimorphia (common opossums) ---- Didelphimorphia is the order of common ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sciurus
The genus ''Sciurus'' contains most of the common, bushy-tailed squirrels in North America, Europe, temperate Asia, Central America and South America. Species The number of species in the genus is subject to change. In 2005, Thorington & Hoffman- whose taxonomic interpretation is followed by the IUCN website- accepted 28 species in the genus: Genus ''Sciurus'' *Subgenus ''Sciurus'' **Allen's squirrel, ''Sciurus alleni'' **Arizona gray squirrel, ''Sciurus arizonensis'' **Mexican gray squirrel, ''Sciurus aureogaster'' **Eastern gray squirrel, ''Sciurus carolinensis'' **Collie's squirrel, ''Sciurus colliaei'' **Deppe's squirrel, ''Sciurus deppei'' **Japanese squirrel, ''Sciurus lis'' **Calabrian black squirrel, ''Sciurus meridionalis'' **Mexican fox squirrel, ''Sciurus nayaritensis'' **Fox squirrel, ''Sciurus niger'' ** Peters's squirrel, ''Sciurus oculatus'' **Variegated squirrel, ''Sciurus variegatoides'' **Eurasian red squirrel, ''Sciurus vulgaris'' **Yucatan squirrel, ''Sciur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (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 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 ranks, such as variety, may be named. In bacteriology and virology, under standard bacterial nomenclature and virus nomenclature, there are recommendations but not strict requirements for recognizing other important infraspecific ranks. A taxonomist decides whether ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geographical Isolation
Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from each other to an extent that prevents or interferes with gene flow. Various geographic changes can arise such as the continental drift, movement of continents, and the formation of mountains, islands, bodies of water, or glaciers. Human activity such as agriculture or developments can also change the distribution of species populations. These factors can substantially alter a region's geography, resulting in the separation of a species population into isolated subpopulations. The vicariant populations then undergo Genetics, genetic changes as they become subjected to different Natural selection, selective pressures, experience genetic drift, and accumulate different mutations in the separated populations' gene pools. The barriers prevent t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation tends to exist within any given population as a result of genetic mutation and recombination. Evolution occurs when evolutionary processes such as natural selection (including sexual selection) and genetic drift act on this variation, resulting in certain characteristics becoming more common or more rare within a population. The evolutionary pressures that determine whether a characteristic is common or rare within a population constantly change, resulting in a change in heritable characteristics arising over successive generations. It is this process of evolution that has given rise to biodiversity at every level of biological organisation, including the levels of species, individual organisms, and molecules. The theory of evolution by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abert's Squirrel
Abert's squirrel or the tassel-eared squirrel (''Sciurus aberti'') is a tree squirrel in the genus ''Sciurus'' native to the southern Rocky Mountains from the United States to the northern Sierra Madre Occidental of Mexico, with concentrations found in Arizona, New Mexico, and southwestern Colorado. It is closely associated with, and largely confined to, mature ponderosa pine forests. It is named in honor of the American naturalist John James Abert; nine subspecies are recognised. It is recognizable by its tufted ears, gray color, pale underparts and rufous patch on the lower back. The squirrel feeds on the seeds and cones of the Mexican pinyon and the ponderosa pine when they are available, but will also take fungi, buds, bark, and carrion. Breeding normally occurs in summer, with a spherical nest being built high in the canopy. Etymology Abert's squirrel is named after Colonel John James Abert, an American naturalist and military officer who headed the Corps of Topographical En ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proceedings Of The Academy Of Natural Sciences Of Philadelphia
The ''Proceedings of the Academy of Natural Sciences of Philadelphia'' is a peer-reviewed scientific journal published by Academy of Natural Sciences of Drexel University The Academy of Natural Sciences of Drexel University, formerly the Academy of Natural Sciences of Philadelphia, is the oldest natural science research institution and museum in the Americas. It was founded in 1812, by many of the leading natura ... since 1841. References External links Publications established in 1841 Academic journals published in the United States Drexel University {{sci-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungus
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from the other eukaryotic kingdoms, which by one traditional classification include Plantae, Animalia, Protozoa, and Chromista. A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related organisms, named the ''Eumycota'' (''true f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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